Dissertation/Thèse

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2022
Thèses
1
  • LEONARDO DE SOUZA DIAS
  • MIX DESIGN METHODOLOGY BASED ON BASIC CONSTITUENT RELATIONSHIPS OF MIXTURES FOR 3D CONCRETE PRINTING (3DCP)

  • Leader : MARCOS ALYSSANDRO SOARES DOS ANJOS
  • MEMBRES DE LA BANQUE :
  • ANA CECILIA VIEIRA DA NOBREGA
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • ULISSES TARGINO BEZERRA
  • Data: 15 févr. 2022


  • Afficher le Résumé
  • 3D printing using cementitious materials has gained prominence in recent research, however there are still many gaps in the parameters required for dosing the mixtures with printability, because these parameters depend on the interaction of the printing system (printer type, pumping, extrusion, printing speed, etc.) with the intrinsic properties of cementitious mixtures, such as particle size of the materials, cement types and mineral additions, volumetric water/binder ratios (Vw/Vb), paste/aggregate volume (Vp/Vs), paste volume (Vp), water volume (Vw) and sand/total solids ratio (S/total solids). This paper analyzed six mixtures for printing with variations in the cement: sand (by mass) ratios, keeping constant the water/dry materials (Vw/Md) ratio, evaluating the printing capacity of these mixtures in a gantry-type 3D printer with mechanized movement in its axes, possessing a material deposition extruder nozzle. The evaluation of the printing capacity was carried out taking into account the visual aspects, pumpability, and filament integrity. The mixtures were then submitted to mini-slump tests, spreading on a consistency table, squezze-flow and deformation under load of the printed filaments at printing intervals of 0, 15 and 30 min, and then the ideal ranges of constitutive ratios of the mixtures (Vp, Vp/Vs, Vw/Vb, Vw, S/solids) compatible with printing were determined. The properties in the hardened state, flexural and compressive strength, adhesion between layers, specific mass and voids index were determined for specimens extracted from printed pieces with cuts in sizes as specified in standards for each test. The results showed that for the printing system used there is an ideal range for these constitutive relations, and that the mixtures even presenting different viscous flow, measured according to squeeze flow, can be printable, as long as they meet the ideal ranges for the determined relations. With respect to the interface of the printed layers, these are critical points of fragility possibly due to factors such as the formation of regions with voids and loss of surface moisture, which favors the reduction of mechanical performance of the parts especially with the increase of deposition time. On the other hand, the increase of time provided a positive effect on the stability and deformation of the filaments, since it favors the stiffness of the substrate offering greater support to the later printed segment.

2
  • FRANCISCA IRES VIEIRA DE MELO
  • CITY INFORMATION MODELING AS A TOOL IN URBAN MANAGEMENT: APPLICATION OF GIS-BIM INTEGRATION

  • Leader : JOSYANNE PINTO GIESTA
  • MEMBRES DE LA BANQUE :
  • JOSYANNE PINTO GIESTA
  • LUCIANA DE FIGUEIREDO LOPES LUCENA
  • LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • TAMMS MARIA DA CONCEICAO MORAIS CAMPOS
  • Data: 18 févr. 2022


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  • Urban centers are becoming increasingly complex environments, causing changes that are expressed both in the city landscape and in people's behavior and lifestyle, thus causing transformations that directly impact the urban socio-spatial structuring. Thus, this study aims to elaborate guidelines for GIS-BIM software integration, in order to facilitate decision making in urban planning. To this end, the Design Science Research (DSR) research method will be used, through which an artifact presenting approaches for GIS-BIM integration was developed, through the compatibility of georeferencing and modeling of a neighborhood in the city of Pau dos Ferros/RN - Brazil. As a result, a proposal with guidelines for GIS-BIM integration was developed and through its application it was possible to obtain the total modeling of the neighborhood with 1,496 modeled buildings, where the parameters of gauge, built area and projection area of the building can be extracted automatically. The development of this integration contributes to reducing the cost of time and resources to produce geographic information, as well as facilitating the visualization and understanding of the territory studied.

3
  • MARCELLA DE SENA BARBOSA
  • DEVELOPMENT OF COMPOSITES FOR 3D PRINTING WITH REDUCED CEMENT CONSUMPTION

  • Leader : MARCOS ALYSSANDRO SOARES DOS ANJOS
  • MEMBRES DE LA BANQUE :
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • ANA CECILIA VIEIRA DA NOBREGA
  • KLEBER CAVALCANTI CABRAL
  • ULISSES TARGINO BEZERRA
  • Data: 22 févr. 2022


  • Afficher le Résumé
  • Recently, 3D concrete printing (3DCP) based on additive manufacturing techniques has been gaining prominence in the construction industry. However, in order to meet the extrusion requirements, 3DCP mixtures are usually dosed with high Portland cement contents. Therefore, a solution seen as promising to make this technology more sustainable is the reduction of cement consumption through partial replacement by mineral additions. In view of this, the present research aims to develop composites for 3D printing containing different percentages of limestone filer and metakaolin as binder fraction of the analysis compositions. The proposed mixtures encompass substitution contents of 30% (using only limestone filer) and 40% (one with 40% limestone filer and another containing 30% limestone filer with 10% metakaolin). In the fresh state, these mixtures were evaluated through the tests of spread, slump, bulk density, incorporated air content, squeeze-flow and buildability. In the hardened state, analyses of flexural strength, compression, adherence between layers, specific mass, void index and water absorption by immersion were performed. In general, the mixtures demonstrated compliance with the requirements of the printer handled. A highlight is given to the composite containing 30% of filer with 10% of metakaolin that, with the ideal amount of mixing water, showed excellent fluidity, good print quality, and ideal viscosity level after extrusion for good shape retention of the printed element. The behavior in the hardened state indicated that it was related to cement consumption. The higher this parameter, the better the mechanical performance of the mixtures. The results show the possibility of obtaining printable composites with reduced cement consumption, establishing itself as a relevant alternative for 3DCP printing by meeting the criteria required for the printing system used.

4
  • GIAN MELO DE SOUZA
  • STUDY OF MIXTURES COMPOSED OF SCHEELITE RESIDUES AND DIFFERENT TYPES OF SOILS INTENDED FOR PAVEMENT

  • Leader : ENIO FERNANDES AMORIM
  • MEMBRES DE LA BANQUE :
  • ENIO FERNANDES AMORIM
  • FAGNER ALEXANDRE NUNES DE FRANCA
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • RENATO SAMUEL BARBOSA DE ARAÚJO
  • Data: 27 juil. 2022
    Ata de defesa assinada:


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  • Over time, the need to reuse solid waste increases to reduce the environmental impacts caused by its storage. Mining is an activity that generates a significant volume of tailings that result from the ore beneficiation process. The scheelite beneficiation process causes a high amount of waste and its largest Brazilian deposit is located in the municipality of Currais Novos, in the scheelite province comprising the Brejuí, Barra Verde, Boca de Laje and Zangarelhas mines. Thus, this research intends to analyze the use of these residues of the coarse, fine and benefited types in mixtures with three local soils, for application in layers of pavements for adequate disposal of these residues. From data obtained in previous research by Barreto (2020), Costa Filho (2017) and Souza (2019) optimized mixtures were obtained to verify possible classification in granulometric gradings of national and international standards with residue proportions of 20, 40 and 60 %. The mixtures of the residue with Soil 01 showed more significant effects because it has coarser granulometry and zero plasticity, demonstrating greater potential for use in road paving. Solo 02 and Solo 03 did not allow compliance with the analyzed regulations due to their higher proportions of fine materials and greater plasticity. According to the Unified Soil Classification System (USCS) and the Highway Research Board (HRB) all mixtures with Soil 01 were considered as coarse-grained materials. In view of its use as base course material, the mixture of Solo 01 with 20% of processed waste made it possible to fit into the “D” and “E” gradings of national and international standards and all mixtures with 20% of waste thickness allowed framing in the “E” grading.

5
  • DENN'S SANTANA PERÔNICA
  • NONLINEAR ANALYSIS OF TRUSSES IN HIPERELASTICITY BY POSITIONAL FINITE ELEMENT METHOD

  • Leader : DANIEL NELSON MACIEL
  • MEMBRES DE LA BANQUE :
  • DANIEL NELSON MACIEL
  • MARCELO GRECO
  • RODRIGO BARROS
  • ROGERIO CARRAZEDO
  • Data: 8 août 2022
    Ata de defesa assinada:


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  • In recent years, there has been an increase in the use of hyperelastic materials in structures, such as vulcanized or natural polymers. As a result, it becomes relevant to expand the knowledge regarding the mechanical performance of these materials through the development of numerical models that simulate their behavior and that are capable of presenting more realistic predictions. For materials represented by hyperelastic models, the consideration of physical and geometric nonlinearities is more adequate to represent their mechanical behavior when subjected to large deformations. Thus, the present work aims at the implementation of a computer program, with the purpose of analyzing and comparing the mechanical behavior of trusses considering the physical nonlinearity, described by hyperelastic models, and the geometric nonlinearity using the positional formulation in finite elements, comparing the result with the linear solutions. The Newton-Raphson iterative algorithm was adopted to solve the problem of non-linearity and the validation of the implemented program took place through the comparison with analytical solutions and experimental results of scientific works.

6
  • VICTOR LINDEMBERG DE LIMA ALENCAR
  • Soil-cement stabilization with the addition of hospital ash  waste 

  • Leader : MARIA DEL PILAR DURANTE INGUNZA
  • MEMBRES DE LA BANQUE :
  • ANA PATRICIA NUNES BANDEIRA
  • ENIO FERNANDES AMORIM
  • MARIA DEL PILAR DURANTE INGUNZA
  • Data: 12 août 2022
    Ata de defesa assinada:


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  • This work presents the analysis of the physicochemical, mineralogical and mechanical behavior of the chemical stabilization of soil with Portland cement and RSS ash as an additive. The technical feasibility of using this compound in layers of road pavements was investigated. A sandy soil, ordinary Portland cement with addition of pozzolan and RSS ash were used. The methodology involved the investigation of the samples from tests of geotechnical characterization of the soil and the mechanical behavior of soil-cement and soil-cement-ash mixtures. Compaction tests were carried out on specimens molded with pure soil and soil-cement in normal, intermediate and modified energies with cement contents added of 0%, 3%, 6% and 9%. The mix that presented the best result was with the addition of 9% of cement, in the modified energy, with an 8.95% increase in strength in relation to the initial one. The CBR test was carried out in pure soil, at a normal energy and humidity above 5.94%, the minimum values of CBR required for sub-base were reached, however, it did not reach the values required for use in pavement bases . Simple compression tests were carried out and, at normal energy and 9% cement content, the result of 25.31 kgf/cm² was found, which meets the minimum required for the use of soil-cement in pavements. This cement content was used for the compression tests with the soil-cement-gray, with the ash content of 5%, 10% and 20% in the normal energy, obtaining the values of 56.62 kgf/cm² , 38.43 kgf/cm² and 32.46 kgf/cm², respectively. In all traces with the addition of RSS ash, the values of the simple compressive strength obtained an increase. The incorporation of up to 20% of ash to the trace demonstrated that it is technically feasible to use RSS ash in the chemical stabilization of soil-cement in sub-bases and pavement bases.

7
  • FÁBIO LINDEMBERG COELHO CORTEZ
  • RELIABILITY ANALYSIS OF THE FOUNDATON OF A HYPERSTATIC VIADUCT: A CASE STUDY

  • Leader : YURI DANIEL JATOBA COSTA
  • MEMBRES DE LA BANQUE :
  • JOHN ELOI BEZERRA
  • LEONARDO HENRIQUE BORGES DE OLIVEIRA
  • YURI DANIEL JATOBA COSTA
  • Data: 22 août 2022


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  • Reliability analysis is an important tool for quantifying uncertainties involved in the design and construction of civil engineering structures. Appropriate failure probabilities and safety factors associated with the maximum allowed risk can be assessed from a reliability analysis. The purpose of this research is to estimate the failure probability of the pile foundation of a hyperstatic viaduct. The foundation of the viaduct included 43 steel H-piles, driven with a hydraulic hammer. The reliability analysis was carried out using the method put forward by Cintra and Aoki (2010) and the Monte Carlo simulation. Mobilized vertical resistances on the piles were estimated using the dynamic formulations by Chellis (1951) and Smith (1960) modified by Aoki (1996). The input parameters required in these formulations are the pile embedded length, the set and the elastic rebound, and were obtained in the field during the driving of the piles. Vertical loads on the top of the piles were estimated following Brazilian standards NBR 7187/2003 and NBR 7188/2013, as well as the Engesser-Courbon method. The input parameters were fitted to normal distributions and were tested with the Kolmogorov-Smirnov hypothesis test. Cintra and Aoki’s (2010) method provided convergent results for both dynamic formulations, around 1/2000. On the other hand, the Monte Carlo method yielded divergent failure probabilities, equal to 1/196 and 1/ 10000, for the solutions by Chellis (1951) and Smith (1960) modified by Aoki (1996), respectively.

8
  • ANTUNES FRANÇA EDUARDO
  • IDENTIFICATION AND EVALUATION OF FLOOD POINTS IN THE NEIGHBORHOODS PETRÓPOLIS AND RIBEIRA IN THE CITY OF NATAL / RN WITH SUPPORT OF GEOTECHNOLOGIES

  • Leader : VENERANDO EUSTAQUIO AMARO
  • MEMBRES DE LA BANQUE :
  • ADA CRISTINA SCUDELARI
  • MARCELO SOARES TELES SANTOS
  • VENERANDO EUSTAQUIO AMARO
  • Data: 26 août 2022
    Ata de defesa assinada:


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  • Urban flooding has become frequent in Brazilian cities due to soil sealing caused by disorderly urbanization of cities, the occurrence of extreme precipitation events and the occurrence of failures in the urban drainage system. In the city of Natal/RN, the neighborhoods of Ribeira and Petrópolis have flood points that cause socioeconomic and sanitary disorders to the population. Thus, this study aims to identify and evaluate areas susceptible to flooding in these neighborhoods based on the use of geotechnologies. For that, topographic, geological, geomorphological, land use and land cover and urban drainage system were integrated into a Geographic Information System (GIS) environment, with the support of in situ ground control bases on the ground obtained with the Global Navigation Satellite System (GNSS). The obtained Digital Terrain Model (MDT) and Digital Surface Model (MDS) allow the identification of topographic depressions and the surface runoff pathway. The results showed the occurrence of eight depressions with surface runoff confluence, among which six with historical occurrence of flooding, besides revealing that the rain drainage system is poorly distributed. Therefore, the areas around the topographic lows are the most susceptible to flooding in this urban sector.

     

9
  • MICHELINE DOS ANJOS E MELLO
  • Thermal degradation of geosynthetics used in flexible pavements with hot mix asphalt

  • Leader : FAGNER ALEXANDRE NUNES DE FRANCA
  • MEMBRES DE LA BANQUE :
  • ENIO FERNANDES AMORIM
  • FAGNER ALEXANDRE NUNES DE FRANCA
  • FERNANDO HENRIQUE MARTINS PORTELINHA
  • Data: 29 août 2022
    Ata de defesa assinada:


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  • The road transport is responsible for a large part of the transport of cargo and people in Brazil, therefore, keeping pavements in good condition implies benefits for the economy and for users, however, it is common for flexible pavement to crack throughout its lifetime. Usually, a new bituminous layer is adopted to repair cracked pavements, but in a short time the cracks are reflected or propagated from the old layer to the new one. A solution adopted to reduce and delay the reflection cracking is the use of geosynthetics, however, these materials can be thermally and mechanically damaged during the installation process. In this way, it is important to verify if these damages are considerable and if they hinder the materials from fulfilling the function for which they were designed. Thus, this research aims to analyze the thermal and mechanical degradation suffered by geosynthetics used as anti-reflective cracking systems and, additionally, to verify if there is an improvement in this analysis with the use of aluminum foil. For this, four types of geocomposites were used and their samples were classified into: virgin samples, which were not subjected to damage; samples with thermal damage, on which the asphalt concrete with high working temperature was deposited and uniformed; samples with thermal and mechanical damage, which, in addition to being subjected to the effect of high temperature, were also exposed to mechanical action due to asphalt concrete compaction. All the damaged samples were
    divided symmetrically and in one part aluminum foil was placed before exposure to the damage and in the other part the asphalt mixture was placed directly, therefore, the damaged samples were categorized as with and without aluminum foil. Afterwards, the samples were cut to be tested according to ASTM D6637 (2015). The results of the tensile tests provided parameters such as tensile strength, grip displacement and slope of the lines. Such parameters were analyzed and used as degradation indicators. It was possible to conclude that the
    severity of damage depends on the raw material of the geosynthetic, as well as the damage type to which it was subjected.

10
  • LUANA RAQUEL JUVINO DA SILVA
  • COASTAL EROSION AND LANDSLIDE RISK MAP ON PIPA BEACH, MUNICIPALITY OF TIBAU DE SUL/RN

  • Leader : VENERANDO EUSTAQUIO AMARO
  • MEMBRES DE LA BANQUE :
  • MARIA DEL PILAR DURANTE INGUNZA
  • PAULO VICTOR DO NASCIMENTO ARAÚJO
  • VENERANDO EUSTAQUIO AMARO
  • Data: 29 août 2022
    Ata de defesa assinada:


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  • The eastern coast of the Rio Grande do Norte (RN) is the domain of active cliffs and sandy beaches, often associated with mobile dunes and fixed by vegetation, intercepted by rivers and estuaries. Along this gological-geomorphological context of natural fragility of the seashore is inserted the Municipality of Tibau do Sul, specifically the stretch of Pipa Beach, where socioeconomic activities are strongly based on international tourism, with repercussions on national and regional tourism, encouraged by the opportunities of business and investments in the real estate sector, in addition to the construction of second homes. Such factors indicate the importance of tourism and real estate activity for the municipality and, consequently, with relevant public and private financing and investments on a range of seafront subjected to intense natural and anthropogenic coastal dynamics, in which disasters have occurred due to use and occupation of land carried out inadequately and based on ineffective public policies. Therefore, the current work presents a methodology for the determination of risk indices in the region of Praia de Pipa/RN based on geospatial databases, reports of historical rainfall data and wave climate reanalysis data, integrated on Geographic Information System. Vulnerability indices were calculated through weighted statistical analysis of thematic classes of geology, geomorphology, land use and occupation, slope, vegetation and extreme precipitation events. The validation of the thematic maps took place throughout the field surveys, in which coastal erosion processes were also verified and investigated, the points of flooding and surface rainwater runoff, as well as the existence of containments structures improperly implanted, which end up enhancing the process of coastal erosion in the area. From the compilation of information collected in the field and analysis of the previous maps, a map of risk of erosion and gravitational mass movements was elaborated to areas defined as high risk (R3) and very high risk (R4). The indexes were calculated through weighted statistical analysis of thematic classes of geology, geomorphology, land use and cover, slope, vegetation and extreme precipitation events. The risk map is essential to strengthen the understanding of coastal areas and provide, to the public managers responsible for the coastal environmental and the community at large, with information that assists in decisions regarding the interventions that could be taken to reduce the degree of risk and in the preparation of contingency plans, as well as for licensing and inspection decisions on coastal regions.

11
  • RAYANNE KARLLA SANTOS DA SILVA
  • DEGRADATION OF GEOSYNTHETICS BY NATURAL WEATHERING IN COASTAL AREA

  • Leader : FAGNER ALEXANDRE NUNES DE FRANCA
  • MEMBRES DE LA BANQUE :
  • ENIO FERNANDES AMORIM
  • FAGNER ALEXANDRE NUNES DE FRANCA
  • FERNANDO HENRIQUE MARTINS PORTELINHA
  • JOSE IVAN DE MEDEIROS
  • Data: 30 août 2022
    Ata de defesa assinada:


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  • Geosynthetics are polymeric materials used in various engineering projects. Among them, its use in coastal protection works stands out with high application potential, together with granular materials for erosion control. The durability, after exposure to the weather, needs to be known for a more accurate dimensioning. Like any polymeric material, they are subject to degradation due to exposure to UV radiation. Both ASTM D5970 (2019) and ASTM D1435 (2013) contain guidelines for the exposure of geosynthetics to UV radiation. In this sense, this work presents a comparison between the two patterns by the change in the exposure slope of a PP geotextile in a coastal environment by the seaside of Natal/RN. In addition, the influence of the color, and consequently the temperature, of the exposure table, as well as its interaction with granular material, was evaluated. The exposure time was 176 days, divided into three distinct periods (42, 84 and 176 days) and the tensile strength of the samples was compared with those obtained from virgins. The results indicated small differences in UV degradation due to the slope of exposure. On the other hand, the color of the exposure table produced greater degradation in those samples exposed on black tables, compared to those on white tables and the most critical result was for samples exposed in sand. The data obtained in this study are essential for the design and adoption of mitigation measures in coastal engineering works that use geosynthetics.


12
  • PLENYO NAHEN GONZAGA ARAÚJO
  • Numerical modeling static liquefaction of aeolian dune sand in a critical state framework

  • Leader : OLAVO FRANCISCO DOS SANTOS JUNIOR
  • MEMBRES DE LA BANQUE :
  • FAGNER ALEXANDRE NUNES DE FRANCA
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • OSVALDO DE FREITAS NETO
  • RICARDO NASCIMENTO FLORES SEVERO
  • Data: 31 août 2022


  • Afficher le Résumé
  • Static liquefaction failure of sloping grounds has resulted in significant damage to built structures and loss of lives. Often, constitutive models, through a Finite Element approach, are used to identify the risks. NorSand is a constitutive model based on critical state soil mechanics for particulate materials that integrate the state parameter into its constitutive framework to model dense and loose sands material with the same parameter set. Importantly, it can identify the liquefaction potential by simulating softening behavior due to pore pressure increase of loose soils in undrained conditions. This work aims to validate the drained and undrained behavior of aeolian dune sand from Natal, Brazil, and predict static liquefaction. The geotechnical software PLAXIS was used to perform the model. The model was validated by comparing simulations to 16 real drained and undrained tests performed on contractive and dilative samples. Undrained triaxial tests were performed at a confining pressure equal to p’0 = 100 kPa in loose states to show the model performance. The results showed the ability of the model to simulate liquefaction failure resulting from the excess pore pressure in undrained stress paths, along with the capability to dilate and compact in drained triaxial compression.

13
  • VALTESON DA SILVA SANTOS
  • Effect of fine content on the critical state parameters of transitional soils
  • Leader : OLAVO FRANCISCO DOS SANTOS JUNIOR
  • MEMBRES DE LA BANQUE :
  • ARTHUR GOMES DANTAS DE ARAUJO
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • OSVALDO DE FREITAS NETO
  • Data: 1 sept. 2022


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  • Misturas de areias e finos apresentam comportamento que diverge dos materiais puros. Essas misturas são chamadas solos transicionais. Diversos estudos observaram que há um teor de finos a partir do qual as propriedades da mistura passam a ser governadas pela matriz de finos. Esse parâmetro é chamado teor de finos de transição. Freire (2019) determinou parâmetros de compressibilidade e resistência para misturas de finos e uma areia provenientes da Formação Pós-Barreiras, coletado na cidade de Natal, Brasil. Este trabalho dá prosseguimento ao trabalho de Freire (2019). O estudo teve como objetivo analisar parâmetros de estados críticos dos mesmos materiais. Os teores de finos utilizados foram: 0, 10, 20, 30, 40, 50, 75 e 100% em relação a massa de sólidos da mistura. Foram realizados ensaios de caracterização geotécnica das misturas e ensaios triaxiais não-drenados para determinação dos parâmetros de estados críticos. Para os ensaios triaxiais não drenados foram utilizadas tensões confinantes efetivas de 50 kPa, 100 kPa e 200 kPa. Foi observado que a linha de estado crítico não é única para as misturas analisadas. O teor de finos de transição obtido pelo modelo de Ueda variou entre 19,7% e 24,3%. O ângulo de atrito efetivo máximo observado ocorreu para o teor de finos de transição. O modelo de empacotamento de Alfred mostrou-se uma boa ferramenta para obtenção do teor de finos que resultaria no maior ângulo de atrito efetivo para o estado crítico. Os resultados obtidos indicam que a distribuição granulométrica da areia e dos finos influencia significativamente o teor de finos de transição. Este trabalho também propõem a aplicação de uma Hipótese Topológica (HT) sobre as transições de fase de misturas de solo. São apresentadas mudanças consideráveis na topologia das misturas que corroboram o comportamento transicional. Por fim, discute-se o conceito de estados críticos de uma visão topológica.

14
  • JOÃO AURIMAR CORREIA DE MORAIS NETO
  • Numerical study of complementary reinforcement in two pile caps with partially embedded socket with shear key interface

  • Leader : RODRIGO BARROS
  • MEMBRES DE LA BANQUE :
  • FABIANA STRIPARI MUNHOZ
  • DANIEL DE LIMA ARAÚJO
  • JOEL ARAUJO DO NASCIMENTO NETO
  • RODRIGO BARROS
  • Data: 25 nov. 2022
    Ata de defesa assinada:


  • Afficher le Résumé
  • Pile caps are foundation elements that presents a complex structural behavior and are characterized by the presence of several sets of reinforcement that aim to improve their characteristics when loaded. In this context, this paper aimed to study the influence of the inclusion of complementary vertical reinforcement in two pile caps with partially embedded socket with shear key interface and to propose new configurations of auxiliary reinforcements for its detailing. Non-linear three-dimensional numerical analyzes were developed using the ABAQUS finite element software. The numerical study was preceded by a peak force calibration step based on experimental results obtained by Barros (2013). After calibrating the model, numerical studies were carried out containing the complementary vertical reinforcement, first, presenting the experimental parameters shown by Barros (2013) and then another study where the fck of the cap was varied between 35, 40, 45 and 50 MPa, which also considered different reinforcement arrangements and steel areas. Stress levels in concrete and reinforcement, shape of struts, slope of stress vectors, cracking and failure mode were analyzed. The results showed that the inclusion of the complementary vertical reinforcement did not cause significant changes in the models studied, even when magnified by four times their steel area. However, the studies identified high tensile stresses in the concrete mass located in the region between the column and the pile with inclinations angle close to 30º, which are caused by the shear of the cap. Based on the reinforcement of such tensile stresses, this research analyzed four proposals for complementary reinforcement. With the exception of the “MA” proposal, the other reinforcements showed satisfactory results in terms of increasing the inclination and shape of the connecting rod, reducing internal cracks in the concrete mass, reducing tensile stresses in the cap and transfer the central loads to regions over the piles. Such benefits translated into an increase in the load capacity of the block by 6.79% to 12.79%.

2021
Thèses
1
  • FELIPE CARLOS DE ARAÚJO LEAL
  • STATIC AND SEISMIC ANALYSIS OF WIND TURBINE FOUNDATION IN PILED RAFT

  • Leader : OSVALDO DE FREITAS NETO
  • MEMBRES DE LA BANQUE :
  • OSVALDO DE FREITAS NETO
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • ALEXANDRE DUARTE GUSMÃO
  • ERINALDO HILÁRIO CAVALCANTE
  • Data: 24 mai 2021


  • Afficher le Résumé
  • The present dissertation proposes to evaluate the static and seismic behavior of piled rafts foundations for a wind turbine located in the city of Macau, on the northern coast of the state of Rio Grande do Norte. Static and seismic analysis were performed using the Finite Element Method, using the ABAQUS software. Initially, in the static analysis, it was observed that in a piled raft with 24 piles (originally predicted number of piles in the foundation design) the raft resisted 63% of the vertical load applied on system, which demonstrates the importance of considering the raft-soil contact in this case. It was concluded, in the static analysis, that a piled raft with 8 piles (RE8) was sufficient to fulfill the necessary safety and displacement criteria. In this case, the raft started to support 85% of the vertical load applied on foundation and the criterion that limited the reduction of more piles was the rotational stiffness, which is related to the differential settlement of the foundation. For seismic analysis, an artificial accelerogram compatible with the seismic conditions observed in Brazil was generated. It was observed that the action of the earthquake at the base of the model caused variations in the loads and vertical displacements of the foundations, as well as in their rotational and translational stiffness, throughout the duration of the event. The RE8, a proposal optimized for a situation of only static loading, experienced an increase in settlement of up to 34% during the seismic loads, as well as decreases of the same order of magnitude in its rotational and translational stiffness. This made the foundation unsuitable for the case, as it did not meet the displacement criteria imposed by the wind turbine manufacturer, as well as the possibility of structural failure due to pile traction. Finally, it was noticed that a piled raft with 20 piles (RE20) fulfilled all the design criteria during static and seismic loads and, therefore, proved to be a suitable foundation proposal for the case. It was concluded that, although the seismic loads are of low magnitude, consistent with the Brazilian territory, it is capable of causing important effects in rigorous structures, such as wind turbine foundations.

2
  • LETÍCIA AZEVEDO DE FARIAS PEREIRA
  • COMPARATIVE ANALYSIS OF PAVIMENTS STRUCTURES USING CDW AND DIMENSIONED FROM DIFFERENT PARAMETERS

  • Leader : ENIO FERNANDES AMORIM
  • MEMBRES DE LA BANQUE :
  • ENIO FERNANDES AMORIM
  • LAURA MARIA GORETTI DA MOTTA
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • VERÔNICA TEIXEIRA FRANCO CASTELO BRANCO
  • Data: 7 juil. 2021


  • Afficher le Résumé
  • This dissertation presents designs of flexible pavement structures developed considering two different methods, which make use of the resilience modulus (MR) and the California Bearing Ratio (CBR), applying soil mixtures with construction and demolition residues/wastes (CDW), and soil-gravel mixtures in base layer and/or sub-base, in order to develop a cost comparison between these methods and between materials. The soil, coming from the city of Ipueira/RN, was identified by the MCT assay as NG’, with non-laterite behavior, the CDW and gravel used had nominal sizes of 19mm. Mixtures of soil-gravel and soil-CDW were made using pure soil and aggregates in the percentages of 15%, 30%, 45% and 60%, by mass. Resilience modulus tests were carried out in all mixtures and permanent deformation (DP) in mixtures with soil-CDW in the proportion of 70% soil and 30% residue. The MR tests were carried out at 1 Hz and the permanent deformation tests with a minimum application of 150,000 load cycles, at 2 Hz frequency. The characterization and analysis of the mixtures showed that the evaluated proportions did not obtain adequate framing in the granulometric ranges for use in the base layer. The results obtained in the RM tests were satisfactory and the mixtures of soil-gravel 70-30 and soil-CDW 70-30 presented the highest values of mean MR. The parameters of the regressions (R²) obtained in the Statistica 10.0 software through the composite model executed based on the data from the MR tests, showed that the mixtures have a significant influence of the confinement and deviation stresses considered simultaneously. Based on the regression parameters, pavement structures designed with the MeDiNa software were proposed. The material selection criterion for the design using the CBR method made it impossible to use the soil-CDW 70-30 in the base layer, but in the design performed in the MeDiNa software it was found that this material can be used in base and sub-base layers, in certain design situations, since it was possible to adjust structures that met the fatigue criteria of the coating and permanent deformations for the useful life period.

3
  • JOÃO PAULO PIERRE VIEIRA

  • Method for production system design of social housing projects with support from the building information modeling process

  • Leader : REYMARD SAVIO SAMPAIO DE MELO
  • MEMBRES DE LA BANQUE :
  • FÁBIO KELLERMANN SCHRAMM
  • JOSYANNE PINTO GIESTA
  • LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • REYMARD SAVIO SAMPAIO DE MELO
  • Data: 23 juil. 2021


  • Afficher le Résumé
  • The Architecture, Engineering, and Construction industry is notably known for its high variability and low productivity. The rational use of resources is decisive for the success of construction projects. In Social Housing Projects, characteristics such as repeatability, short deadlines, and several units make production scheduling a decisive activity in the enterprise's results. The production system design (PSD) can organize the production system and structure resources in a manageable way. In this way, the planning of processes and construction represent a differential in the development of projects. Thus, Building Information Modeling (BIM) emerges as an essential ally in production management. Previous studies indicate synergy between these two areas. However, these studies are incipient, approaching the interaction between PSD and BIM implicitly and not presenting the relationship between the two themes. This research aims to propose a method of developing PSD for Social Housing Projects with support from BIM. The research method employed was Design Science Research. The proposed method was divided into pre-modeling, base unit modeling, and enterprise modeling.

4
  • ADNA ÉRICA MELO DE SOUSA FONTES
  • MECHANICAL, THERMAL AND ACOUSTIC ANALYSIS OF MORTARS WITH REPLACEMENT OF FINE AGGREGATE BY EXPANDED CLAY

  • Leader : KLEBER CAVALCANTI CABRAL
  • MEMBRES DE LA BANQUE :
  • KLEBER CAVALCANTI CABRAL
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • WENDELL ROSSINE MEDEIROS DE SOUZA
  • Data: 27 juil. 2021


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  • In the Civil Construction scenario, the thermal and acoustic performance of buildings is a relevant topic for scientific research, especially after the publication of ABNT NBR 15575:2013, known as the performance standard. Under this bias, the objective of the work was to analyze the mechanical, thermal and acoustic behavior of lining mortars, using different contents of a fine fraction of expanded clay as a partial substitute for the conventional aggregate. To carry out the work, the thermal conductivity of the mortars was determined and laboratory tests were carried out with the aid of incidence and heat transfer and noise simulators in the samples, as well as tests to determine the physical properties of materials and mechanical properties of the mixtures. The results show that the mortars incorporating expanded clay did not show significant impacts on their mechanical properties and with regard to sound insulation. On the other hand, it was observed that the increase in the expanded clay content in the composition of the mixes reduced the thermal conductivity and increased the thermal insulation of the samples. Thus, the influence of light aggregate on the thermal behavior of the mortars under study is evident, without compromising their mechanical and acoustic behavior.

5
  • LISIEUX FEITOSA GONDIM PIPOLO
  • Study of cement paste with partial and total replacement of manipueira by mixing water.
  • Leader : WILSON ACCHAR
  • MEMBRES DE LA BANQUE :
  • WILSON ACCHAR
  • LUCIANA DE FIGUEIREDO LOPES LUCENA
  • JAQUELIGIA BRITO DA SILVA
  • SHEYLA KAROLINA JUSTINO MARQUES
  • VAMBERTO MONTEIRO DA SILVA
  • Data: 28 juil. 2021


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  • Cement paste is the union of two basic inputs in the civil construction sector, water, and cement. From it, mortar and concrete, the most consumed elements in the construction industry, are prepared. Given the great demand for these inputs, some questions arise about the environmental impact, regarding the high consumption of natural resources and the social impact of the use of treated water for less noble activities than human supply. In this way, researches have been developed to replace the traditional materials of cement paste with by-products that provide similar or better properties in cementitious materials and minimize the consumption of natural goods by replacing them with by-products from other productive activities. The cassava processing process (Manihot esculenta Crantz) for the production of starch and flour generates cassava, a milky liquid by-product that flows from the roots during the pressing process with a high content of hydrocyanic acid and high biochemical oxygen demand (BDO). In 2020, Brazil was responsible for the production of 18.96 million tons of cassava root, which is equivalent to 14.95 ton/ha. It is estimated that the production of manipueira reaches a ratio of 3:1, for each 3kg of pressed roots, 1 of cassava leaves is generated. Accumulation in small surrounding areas or its disposal in water bodies (alteration of self-purification and eutrophication capacity). Considering this context, the objective of this research is to analyze the behavior of the cement paste in the fresh and hardened state, in addition to its microstructure when replacing totally and partially the hydration water by liquid cassava. In this way, seven proportions of replacement of liquid cassava by the hydration water of the cement paste in 10%, 15%, 20%, 25%, 50%, 75%, and 100% were studied. The characterization of cement and manipueira (by-product) was carried out. Next, the pastes were analyzed for their properties in the fresh state (normal consistency, mini-slump, and setting time) and hardened (compressive strength, flexural tensile strength, capillary absorption, immersion absorption, bulk density). They were carried out in the samples of compositions of l counted with Scanning Electron Microscopy (SEM), X-Ray Diffraction (DRX), X-Ray Fluorescence (FRX), and Thermogravimetry (TG/DTG). In the fresh state, the presence of manipueira caused a delay in setting time and promoted a plasticizer behavior to the cement pastes in all the proposed formulations. In the hardened state, it promoted an increase in compressive strength in formulations with up to 20% replacement and a sharp drop in other proportions. It was also verified a decrease in specific mass, an increase in the void index, and absorption by capillarity in all variations of replacing the cassava tree with water. The results indicated that the formulation of the cement paste with replacement of the hydration water by cassava plant with the best performance in the evaluated items was 20%, making the by-product, cassava mill viable, as a viable material for application in cement-based products.

6
  • JEANDSON WILLCK NOGUEIRA DE MACEDO
  • Coating mortar produced from the replacement of natural aggregate with scheelite residue and stone dust
     
  • Leader : WILSON ACCHAR
  • MEMBRES DE LA BANQUE :
  • JAQUELIGIA BRITO DA SILVA
  • LUCIANA DE FIGUEIREDO LOPES LUCENA
  • SHEYLA KAROLINA JUSTINO MARQUES
  • VAMBERTO MONTEIRO DA SILVA
  • WILSON ACCHAR
  • Data: 28 juil. 2021


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  • The exploration of aggregates involves the extraction of non-renewable natural resources, and with that, it modifies the environment, causing environmental impacts. In 2019 alone, Brazil produced around 312 million tons of sand, an aggregate that is usually extracted from river beds, causing various damages to the environment, such as erosion, siltation of rivers, and soil contamination. In this context, the reuse of waste is an alternative that connects the economy to sustainability, mainly due to its ability to reduce production costs and, at the same time, promote the reduction of consumption of natural resources, as well as providing adequate management for by-products from various industries, such as those from the scheelite beneficiation process and rock crushing. The state of Rio Grande do Norte concentrates the largest reserves of scheelite in Brazil, which are explored to obtaining tungsten, one of the most used minerals in the production of various industrial segments. During the extraction of this element, tons of solid waste are generated and stored outdoors, occupying large areas, providing impacts to the environment. Stone dust is the fine by-product originating from the rock crushing process to obtain gravel for civil construction, which, in turn, is usually deposited in the quarries yard, in large volumes, providing various environmental impacts and respiratory diseases. In Brazil, this by-product is used mainly in the production of concrete and industrialized mortar, however, its use in the production of mortar and concrete in construction works is still very limited. Faced with this problem, this research aims to study the performance of coating mortars produced with total replacement of natural aggregate by residual binary sands consisting of stone dust and scheelite by-products. For this, the characterization of waste and materials used in the manufacture of mortars was carried out, including FRX, DRX, and SEM analyses. Then, mortars were formulated at a ratio of 1:3 in volume, with total replacement of natural sand by residual scheelite sand and crushing.  The mortars were analyzed for their properties in the fresh state (consistency, mass density, incorporated air content, and water retention) and hardened (tensile strength, compression strength, immersion absorption, capillary absorption, bulk density, and microstructure). In the end, coatings were performed, which in turn, were evaluated for adherence to traction. The study of the packing and particle size distribution of the aggregates allowed the production of high-quality residual sand from the combination of stone dust and coarse scheelite residue, which are significant environmental liabilities of mining in the state of Rio Grande do Norte, Brazil. The mortar produced with this composition, in the fresh state, although denser, had better consistency, greater water retention, and incorporated air content similar to the reference mortar. In the hardened state, the formulation achieved high mechanical strength, higher mass density, lower absorption, both by immersion and capillarity, among all the evaluated mortars, as well as a tensile adhesion performance close to the reference mortar and, above the minimum values established by Brazilian standards for mortar coatings, which confirms the feasibility of using the composition of crushing sand and scheelite as an aggregate for mortars.

     
7
  • LUIZ RICARDO DA SILVA LINHARES
  • Semirigid concections analysis for dynamic nonlinear 2D frames

  • Leader : DANIEL NELSON MACIEL
  • MEMBRES DE LA BANQUE :
  • DANIEL NELSON MACIEL
  • JOEL ARAUJO DO NASCIMENTO NETO
  • MARCELO GRECO
  • Data: 29 juil. 2021


  • Afficher le Résumé
  • In the design of high-performance structures, a dynamic analysis with physical and geometric nonlinearities is commonly used, using the Finite Element Method (FEM). In this context, there are some gantries that adopt devices for the control of vibrations, as well as the presence of non-linear semi-rigid connections. However, in order to carry out a refined structural analysis, it is necessary to consider these aspects in the projects. The objective of this work is to evaluate an alternative way of including viscoelastic bonds with non-linear behavior through a formulation that uses nodal positions instead of displacements as unknowns of the problem, called positional formulation. The Reissner kinematics will be used to consider the effects of shear, the Newton-Raphson iterative algorithm will be adopted to solve the nonlinear problem and the Kelvin-Voigt rheological model to represent the viscoelastic behavior of the bonds. The validation of the implemented code will be done through the resolution of numerical examples from the literature.

8
  • FLAVIANO FERREIRA DOS SANTOS NETO
  • 10 years of expressive real estate production in Natal/RN: Spatial distribution

     
  • Leader : LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • MEMBRES DE LA BANQUE :
  • JOSYANNE PINTO GIESTA
  • LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • LUIZ FERNANDO MAHLMANN HEINECK
  • Data: 30 juil. 2021


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  • This work aims to promote a spatial analysis of the real estate developments that were registered from 2005 to 2014 in the city of Natal/RN, in order to analyze how the real estate developers acted in the urban space, producing what? Where? and when? For this, one of the content analysis techniques was applied to the documents that make up the real estate development registry, in order to develop a methodological sequence that can be replicated in any Brazilian city, thus favoring dissemination of the production process and systematization of a nationwide georeferenced database. By following this methodological itinerary, an analysis universe was formulated containing more than 300 developments, arranged in 5 different types of real estate projects. This information was analyzed from some perspectives that favor the detailing of the phenomenon studied, namely: number of floors, construction pattern of housing units, composition of real estate production and annual volume of launches. The results indicate that 75% of the city's real estate production is arranged in 4 urban agglomerations, relatively homogeneous, with their own location, predominant construction typology and well-defined expansion period. This type of analysis transcends the spatial and collaborates to identify the existence of factors that contributed to the formation of such characteristic types of production, such as: urban legislation, the population's wage income, the circulation of international tourists in the city and the Federal Government housing programs.

     
9
  • THAYANNE LARA GONDIM SILVA
  • REAL ESTATE PROMOTION AND MAIN ROADS: A STUDY ON SPATIAL CORRELATION IN NATAL/RN

  • Leader : LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • MEMBRES DE LA BANQUE :
  • ALMIR MARIANO DE SOUSA JUNIOR
  • LUCIANA DE FIGUEIREDO LOPES LUCENA
  • LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • MAGDA MARIA PINHEIRO DE MELO
  • Data: 18 août 2021


  • Afficher le Résumé
  • The real estate development developed in the city of Natal followed the economic transformations and urban legislation in force in the city, defining the location of the projects and their typological characteristics, acting as an important agent for transforming the urban space. The performance of real estate developers contributed to the process of urban expansion, promoting population density in specific regions of the city. The consequent increase in the number of vehicles and the deficiency in the expansion of road infrastructure resulted in the compromise of urban mobility. This work aims to establish possible spatial correlations between vertical housing production, in the period from 1990 to 2018, and arterial roads in the city of Natal. For this, an extensive database was used, and, through the QGIS® software, aspects of the spatial distribution of the projects were defined, emphasizing the number of housing units, the verticalization (number of floors) and the number of parking spaces . The results point to an asymmetrical distribution of housing units between the administrative zones of Natal, but a direct relationship between the construction of projects and arterial roads, since many of them follow the extension of these roads. The East and South Zones concentrate the largest number of housing units, buildings with the highest number of floors and with greater availability of parking spaces, unlike the North and West Zones, which bring together real estate production for populations with lower purchasing power. The presence of infrastructure, the concentration of stores, services in education, health and leisure and better access routes may justify the greater intensity of projects in the East and South Zones, revealing possible criteria in the decision-making process of real estate developers. Due to the proximity of the properties to arterial roads, congestion points, environmental pollution by the emission of gases and higher noise levels can already be observed in these areas. The conclusions of this research can support both the decision-making of promoters and contribute to the public authorities to adopt measures and actions to guide the best use of infrastructure, without compromising urban mobility, affecting the quality of life of people.

10
  • BRUNO ÍTALO FRANCO DE OLIVEIRA
  • LIFE CYCLE COST EVALUATION OF CEMENTARY MATERIALS: A STUDY FOR INDUSTRIALIZED MORTARS.


  • Leader : LUCIANA DE FIGUEIREDO LOPES LUCENA
  • MEMBRES DE LA BANQUE :
  • CLAUDIA COUTINHO NÓBREGA
  • JOSYANNE PINTO GIESTA
  • LUCIANA DE FIGUEIREDO LOPES LUCENA
  • Data: 1 sept. 2021


  • Afficher le Résumé
  • The construction industry is one of the biggest consumers of energy and materials. Understanding how this consumption occurs during its life cycle is extremely relevant for planning changes for the sector. Thus, considering the importance of analyzing the environmental and economic aspects of these materials from the perspective of the life cycle, this research sought to identify the impacts caused by the production of cementitious materials, in particular the ACII mortar, based on a study of case in a company located in the interior of the Northeast, using a life cycle cost (LCC) methodology. Costs were assessed using a costeffective approach, associating the internal and external lifecycle costs of the crib to the gate. The production of mortars was analyzed using alternative scenarios in order to minimize the uncertainties inherent to the process. For each scenario, mitigating alternatives for the main associated environmental impacts were analyzed, in order to verify their feasibility and effectiveness. The CCV results showed that cement has a high economic and environmental impact and that internal costs are the biggest contributors to the total costs of the process, due to the high amounts of raw materials and inputs used and the company's quest to become more sustainable. The heated economy scenario enabled better results in terms of economic viability, mainly motivated by the low dollar exchange rate. The scenario with economy in retraction, on the other hand, can make it difficult for measures to reduce environmental impacts to be implemented, thus making it difficult to improve production. The use of personal protective equipment, together with the installation of an exhaust system and the replacement of common portlant cement with LC3 cement, proved to be a viable and effective way to mitigate the associated environmental impacts, however, they require many resources and time for its implementation. The study concludes that the inclusion of life cycle thinking in the decisionmaking process proved to be of paramount importance for obtaining a more sustainable production, since it considers the different stages of the life cycle. 

11
  • FERNANDA KAREN MELO DA COSTA
  • Influence of concrete strength in live load bending moment distribution in bridges widened

  • Leader : JOSE NERES DA SILVA FILHO
  • MEMBRES DE LA BANQUE :
  • JOSE NERES DA SILVA FILHO
  • RODRIGO BARROS
  • RODRIGO GUSTAVO DELALIBERA
  • Data: 17 sept. 2021


  • Afficher le Résumé
  • This research consists of the analysis of the distribution of bending moments and shear forces due to the live load in the beams of straight reinforced concrete bridges that have undergone a process of enlargement of the superstructure. For this purpose, analytical models of load sharing in bridge decks were developed based on the principles of the Leonhardt method and numerical models, using the Finite Element Method (FEM), with the aid of the CSiBridge® program, version 21. Bridge situations with different numbers of beams and with concretes of different strengths in the widening region were analyzed, which allowed to conclude that the distribution of forces between beams of the same geometry fundamentally depends on the strength of the concrete in the widening region and that the greater it is the strength of the concrete in the widening more efforts are absorbed by the new beams and less by the existing beams. In addition, it was found that the increases and decreases in efforts in the beams as a function of the concrete strength follow closely linear functions and, mainly, 2nd order polynomials.

12
  • YNGRID RAYANE FREITAS DO NASCIMENTO
  • Widened curved bridges: an analysis of the distribution of bending moments and shear forces due to the live load.

  • Leader : JOSE NERES DA SILVA FILHO
  • MEMBRES DE LA BANQUE :
  • JOSE NERES DA SILVA FILHO
  • RODRIGO BARROS
  • GILBERTO GOMES
  • LEANDRO MOUTA TRAUTWEIN
  • Data: 18 oct. 2021


  • Afficher le Résumé
  • A significant fraction of Brazilian bridges is at risk of becoming functionally obsolete and structurally deficient if they are not reinforced and widened to conform to the new dimensional and load patterns. Still, technical literature mainly focuses on designing and constructing new structures, leaving the field of bridge widening relatively unexplored. In this context, this research aims to analyze the distribution of bending moments and shear forces due to the mobile load in curved bridges that have undergone a process of widening. This approach allows an analysis of how the transverse variation of stiffness affects bending moment and shear force distribution. The study considered the variation of additional segment's concrete strength, curvature radius, girder number, and cross-section type, as well as diaphragm insertion, 72 models were developed. The results were based on Bending Moment (BMDF) and Shear Force Distribution Factor (SFDF), which were obtained through FEM, using the CsiBridge v22. The analysis considered the design truck in two different positions on the deck, constituting the load cases 01 and 02. Additionally, this work contemplates two approximated analytical methods (V-Load and M/R), whose results were confronted with those determined through FEM. In conclusion, the variations tend to grow with the strengthening of the additional segments. Regarding load case 02, in general, stresses relocate toward the additional and stiffer areas, relieving the original girders. However, concerning load case 01, more often than not, the additional internal girders also experience stress reduction, which is not desirable. In relation to the curvature radius, it was found that this parameter does not alter the effects provoked by transverse stiffness variation. Comparing the results from MEF with those from the V-Load Method, it was verified that the divergences tend to increase with the reduction of curvature radius. Also, this comparison is not significantly affected even in models with variable stiffness along the cross-section. The M/R method was found inadequate, considering that its results for the internal girders tend to be unconservative.

13
  • NICOLE NAHARA SOUZA DE OLIVEIRA
  • ANALYSIS AND MODELING OF STRUCTURAL MASONRY SHEAR WALLS CONSIDERING THE CRACKING EFFECTS

  • Leader : JOEL ARAUJO DO NASCIMENTO NETO
  • MEMBRES DE LA BANQUE :
  • JOEL ARAUJO DO NASCIMENTO NETO
  • RODRIGO BARROS
  • JOSÉ CARLOS LOPES RIBEIRO
  • GUILHERME ARIS PARSEKIAN
  • Data: 28 oct. 2021


  • Afficher le Résumé
  • This research consists an analyze of structural masonry shear wall behavior considering the effects of the cracking in mortar joints taking into account the cracking effects. For this purpose, it was used the simplified Equivalent Bars Model, including link elements between the bars to simulate the cracking numerically. The analyzes were performed using the software SAP2000 and consisted in the modeling of some shear walls that was tested experimentally by outher reseacher. In a second step, we proceeded with the modeling of a real building with 19 floors, using the equivalent bar model with link elements and a hybrid model formed by joining the MBEq and the Three-dimensional Portico, based on Yagui model. The results indicated that the idealized computational modeling reproduced consistently the effects of cracking, properly simulating the nonlinear behavior of masonry The results have shown that the idealized computational modeling reproduced satisfactory the effects of cracking, simulating the nonlinear behavior of the masonry.

14
  • DANIEL ALVES DE LIMA
  • Dynamic analysis of 2D frames using the Finite Element Method

  • Leader : RODRIGO BARROS
  • MEMBRES DE LA BANQUE :
  • AREF KALILO LIMA KZAM
  • FERNANDA RODRIGUES MITTELBACH
  • RAIMUNDO GOMES DE AMORIM NETO
  • RODRIGO BARROS
  • Data: 29 oct. 2021


  • Afficher le Résumé
  • The dynamic analysis of 2D frames is a relevant topic for structural engineers, since the civil construction advances, in a quick way, technologically as the time passes. This allows the creation of increasingly taller structures which are highly stressed due to dynamic loads, such as the wind. Thus, this work aims at the development of a computational code using MATLAB software and its language of the same name. The code solves 2D portals problems through the Finite Elements Method (FEM), using frame elements, obtaining the internal efforts of the structure, and in addition it analyzes certain displacements, at the user's discretion, through two methods consolidated in the study of structural dynamics, the methods of Newmark and Houbolt. Additionally, the load intensity varies over time, through a sinusoidal function, and the deformed configuration of the structure is plotted.

15
  • ANDERSON NUNES SILVA
  • EVALUATION OF THE MECHANICAL BEHAVIOR OF CONCRETE REINFORCED WITH RESIDUAL POLYESTER FIBERS

  • Leader : LUCIANA DE FIGUEIREDO LOPES LUCENA
  • MEMBRES DE LA BANQUE :
  • LUCIANA DE FIGUEIREDO LOPES LUCENA
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • VIVIANE MUNIZ FONSECA
  • LÊDA CHRISTIANE DE FIGUEIRÊDO LOPES LUCENA
  • Data: 29 oct. 2021


  • Afficher le Résumé
  • The use of residual fibers in the composition of concrete has been the object of several researches that seek to obtain fibers at lower cost, considering materials considered unserviceable and enabling improvements in the physical and mechanical properties of this composite. In this perspective, this research aims to evaluate the effect of incorporating rubberized polyester waste in the mechanical mechanism of concrete. For this purpose, they were analyzed as properties in the fresh and hardened state of conventional concrete reinforced with residual polyester fibers, in two lengths (40mm and 60mm) and in three contents (0%, 0.15% and 0.30% in in relation to the volume of the concrete). In the fresh state, the slump test was performed and for the hardened state, at 28 days, the tests of physical index, axial compression strength, tensile strength by diametrical compression, tensile strength in bending, tensile strength in fracture and tenacity. The results of the treatments increased that the addition of fibers causes a reduction in workability as the addition content and length of the fibers increase. In the hardened state, it was observed that with the addition of fibers there is a tendency to increase the void index and the water absorption content of the concrete. Fiber-reinforced concrete with a lower density than fiber-free concrete. The fibers increased the axial compression strength and tensile strength by diametrical compression of all the mixes, with the 40mm fiber reinforced mixes better results. In no flexural tensile test, the mixes reinforced with 60mm residual fibers had the best performance, with the 0.15% reinforcement content changed being the best result. Concretes with fiber fibers tenacity higher than the reference mix. Finally, it was verified that the residual polyester fibers allowed improvements in some mechanical properties of the concrete, increased the deformation capacity and the strength of the cementitious composite.

16
  • HUEDLY CHAVES DOS SANTOS
  • Evaluation of self-compacting concretes with RCD sand reinforced with steel and polyethylene fibers subjected to chloride accelerated

  • Leader : MARCOS ALYSSANDRO SOARES DOS ANJOS
  • MEMBRES DE LA BANQUE :
  • KLEBER CAVALCANTI CABRAL
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • ULISSES TARGINO BEZERRA
  • Data: 1 nov. 2021


  • Afficher le Résumé
  • The production of Construction Waste (CW) has been growing every year, and to dispose of it correctly has become a necessity. One solution is to reuse it as recycled aggregate in concrete. However, its use as a substitute for natural aggregates in concretes shows that there is a reduction in durability properties, as well as mechanical strengths. To alleviate this problem, the addition of fibers to the concrete and the use of self-compacting concrete (SCC) can be alternatives to improve the mechanical behavior, since the SCC use low water / cement ratios. Recently, the research has intensified the study of CW in concrete, with the objective of understanding its behavior. The objective of this paper is to evaluate the mechanical behavior under to compression and bending stress, the tenacity and the durability of self-compacting concrete with the addition of steel fibers and commercial polyethylene, combined with the use of recycled aggregate as fine aggregate with recycled aggregate from CW, fighting the action chloride ions through accelerated physical salt attack cycles. The definition of the fiber content and superplasticizer additive was carried out by means of the study of mortars to then verify the behavior of the SCC in the fresh state. In the hardened state, the behavior of compression, bending and toughness must be applied before and after cycles of wetting and drying in saline solution, in addition to the determination of the diffusion coefficient of chloride ions. Compressive strengths, flexural tensile strength and toughness are expected to show better results in SCC with fibers compared to SCC without fibers, especially in SCC with steel addition fibers. As for the behavior against the attack by chloride ions, there is no consensus on the behavior of concretes using CW, as there are works that indicate better behavior and there are works that indicate worse, in addition, there are few works that replace the fine aggregate with CW.

17
  • RAQUEL FERREIRA DO NASCIMENTO
  • EFFECT OF HYDROXYPROPYLMETHYLCELLULOSE ON LIGHT THERMAL MORTARS BASED ON EXPANDED VERMICULITE

  • Leader : KLEBER CAVALCANTI CABRAL
  • MEMBRES DE LA BANQUE :
  • KLEBER CAVALCANTI CABRAL
  • LUCIANA DE FIGUEIREDO LOPES LUCENA
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • WENDELL ROSSINE MEDEIROS DE SOUZA
  • Data: 1 nov. 2021


  • Afficher le Résumé
  • Insulating and low-density cementitious materials have been increasingly studied in order to improve thermal insulation conditions in buildings and the possibility of reducing the weight of buildings. One of the ways to develop this type of material is through the use of light aggregates or additives that allow the incorporation of air. Thus, the present study aims to verify the influence of the use of Hydroxypropylmethylcellulose (HMPC) on the thermal and mechanical properties of light mortars based on expanded vermiculite, with replacement of sand by light aggregate in the proportions of 0%, 20%, 40 %, 60% and 100%, for sets of mortars with and without HPMC. To determine the properties of the fresh and hardened state of the mortars, the tests of compressive strength and tensile strength in bending, water absorption by immersion, mass density, modulus of elasticity and water loss by evaporation were performed. The thermal performance was obtained through the simplified method of NBR 15575-3 (ABNT, 2013) and through a simulator. The results indicate that the incorporation of HPMC causes an increase in the material's void index, promoting a reduction in mechanical strength and elastic modulus. This fact does not constitute an obstacle to its use, because, for a coating mortar, it is important to have flexibility in order to acquire a greater possibility of absorbing deformations. It is also noted that the incorporation of HPMC produces a mortar with lower mass density, reflecting in a lighter material with high thermal insulation capacity, in such a way that the 100% vermiculite composition can insulate approximately 20°C, while the complete system (mortar+brick+mortar) insulates approximately 43ºC, values that are higher when compared to the mortar without HPMC. Thus, it is concluded that the incorporation of HPMC allowed an increase in thermal insulation in light mortars based on vermiculite, due to the increase in the void ratio provided by this additive, directly influencing the mechanical properties of the material.

18
  • ALBERT JONATHA BATISTA
  • CHARACTERIZATION OF GRANITE QUARRY WASTE FOR GEOTECHNICAL PURPOSES

  • Leader : MARIA DEL PILAR DURANTE INGUNZA
  • MEMBRES DE LA BANQUE :
  • MARIA DEL PILAR DURANTE INGUNZA
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • ANA PATRICIA NUNES BANDEIRA
  • Data: 4 nov. 2021


  • Afficher le Résumé
  • The municipality of Parelhas-RN can be considered as one of the main producers of ornamental stones,
    mainly composed of granites and marbles, from the state and the northeast region. Nowadays, due
    the great concern with the environment, the debate about reusing materials is increasing, aiming the economic impacts and environmental issues. Based on that and the large volume of waste generated by the mining company, the main objective of the present work is to characterize waste from the granite mining process of a mining activity located in the city of Parelhas-RN and to identify the potntial uses for the waste, replacing natural aggregate, in geotechnical purposes. The following characterizations were carried out: microstructural and chemical characterization, physical characterization and mechanical characterization. The microstructural and chemical characterization was carried out  by scanning electron microscope (SEM). The physical characterization was composed by tests to determine the specific mass, absorption and porosity accordind to ABNT NBR 15845-2: 2015 standard, the mechanical characterization was performed to determine the mechanical streght of the samples, according to ABNT NBR 15845-5: 2015. In general, the samples collected, at the three collection points, obtained high mechanical strength, indicating that the unaltered samples can be used as a natural aggregate for geotechnical purposes.

19
  • WILLIAM VIEIRA GOMES
  • URBAN FLOODING ANALYSIS FROM UNMANNED AERIAL VEHICLES: A CASE STUDY IN PAU DOS FERROS/RN

  • Leader : VENERANDO EUSTAQUIO AMARO
  • MEMBRES DE LA BANQUE :
  • ADA CRISTINA SCUDELARI
  • JORGE LUÍS DE OLIVEIRA PINTO FILHO
  • VENERANDO EUSTAQUIO AMARO
  • Data: 12 nov. 2021


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  • Brazilian cities, given the rapid urban expansion and the lack of infrastructure in terms of sanitation services, are highly susceptible to the occurrence of environmental disasters, especially floods and flooding. Thus, this work aimed to develop a method for analyzing urban flooding based on high spatial resolution Digital Elevation Models (DEM) through the photogrammetric processing of Unmanned Aerial Vehicle (UAV) images, associated with strategic survey in GNSS. For this purpose, bibliographic and cartographic research was carried out. An aerophotogrammetric survey was carried out, enabling the verification of image quality and alignment; the production of three digital surface models (MDS), one being simplified, unchanged and corrected; and the production of an orthomosaic. Remote sensing was also used, enabling a delimitation of the drainage network, micro-basins, topographic depressions and flood simulation. Thus, 7 topographic depressions were identified and two drainage galleries were modeled. In these depressions, the misallocation of existing drainage instruments or even their inexistence was found, impacting no potential for accumulation of rainwater in its entirety. In other cases, the accumulated rainwater only flows to other locations after a depth of 30 cm.

20
  • BIANCA ALENCAR VIEIRA
  • xxxxxxxxxxx

     
  • Leader : CARINA MAIA LINS COSTA
  • MEMBRES DE LA BANQUE :
  • Caroline Tomazoni Santos
  • FERNANDO HENRIQUE MARTINS PORTELINHA
  • YURI DANIEL JATOBA COSTA
  • Data: 26 nov. 2021


  • Afficher le Résumé
  • xxxxxxxxxxxx

     
21
  • DIEGO LIMA DANTAS
  • NON-LINEAR ANALYSIS OF REINFORCED CONCRETE PILE CAPS AS A FOUNDATION OF ONSHORE AIR GENERATOR CONSIDERING THE LATERAL FRICTION BETWEEN PILES AND THE SOIL

  • Leader : RODRIGO BARROS
  • MEMBRES DE LA BANQUE :
  • JOEL ARAUJO DO NASCIMENTO NETO
  • JOSE NERES DA SILVA FILHO
  • RODRIGO BARROS
  • RODRIGO GUSTAVO DELALIBERA
  • Data: 29 nov. 2021


  • Afficher le Résumé
  • In the search for alternative sources to meet the growing demand for energy, wind production has been highlighted due to the great potential for its use in Brazil. Given the magnitude of the foundations of wind turbines, understanding their structural behavior is essential for designing optimized solutions that reduce costs and facilitate the implementation of this technology on a large scale. From this perspective, this research seeks to deepen the studies on the structural behavior of foundations for onshore wind turbines, represented by reinforced concrete pile caps. Computational models were developed using the Finite Element Method (FEM) with the aid of the Ansys Workbench R20 software, considering the contribution of the lateral friction of the pile shaft in the conduction of loads to the ground, using non-linear numerical modeling. The reinforcements of a wind tower foundation were designed and two different mesh organizations were proposed: circular (CR) and orthogonal (OR). It was observed that the reinforced blocks, although classified as flexible foundations due to their geometry, presented a behavior similar to that of rigid blocks, with a tendency to linearize the reactions and vertical displacements. The results showed that the distribution of reinforcement in orthogonal mesh provided smaller vertical displacements for the blocks. In the different types of soils considered, the vertical displacements of the OR models were, on average, 10.74% lower than those of the CR models. On the other hand, the consumption of steel, in kilograms, was considerably lower in the CR models. The amount of steel used in the reinforcement of the CR models was 30.97% smaller than in relation to the OR models.

22
  • IVENS LORRAN CLEMENTE DE LACERDA
  • NÃO CONSTA

  • Leader : ADA CRISTINA SCUDELARI
  • MEMBRES DE LA BANQUE :
  • ADA CRISTINA SCUDELARI
  • CYNTHIA ROMARIZ DUARTE
  • VENERANDO EUSTAQUIO AMARO
  • Data: 1 déc. 2021


  • Afficher le Résumé
  • Não consta

23
  • ALINE RIBEIRO DA SILVA
  • MAPPING RISK OF MASS MOVEMENT IN MÃE LUÍZA, APARECIDA SECTOR, NATAL / RN

  • Leader : OLAVO FRANCISCO DOS SANTOS JUNIOR
  • MEMBRES DE LA BANQUE :
  • ANA PATRICIA NUNES BANDEIRA
  • LEONARDO FLAMARION MARQUES CHAVES
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • RICARDO NASCIMENTO FLORES SEVERO
  • Data: 8 déc. 2021


  • Afficher le Résumé
  • The occupation of slopes near riverbanks is quite recurrent in many regions of Brazil. Most of them irregularly and occurring without adequate planning. Due to that, natural characteristics unsuitable for land use, along with anthropic actions, end up causing mass movements, which can seriously affect the local communities. In Natal do Rio Grande in the North, this reality also occurs, as is the case of the neighborhood of Mãe Luíza. Given this scenario, this study aims to map the risks of mass movement in an area belonging to the neighborhood of Mãe Luíza, between Camaragibe and Atalaia streets. The risk mapping of the area under study was carried out based on the methodology proposed by Brazil (2007). Three classes of risks were defined: low, medium and high risk. Three critical areas were analyzed, in which thirty-four properties were analyzed. Among these, only six are at risk of medium mass movement and all the other twenty-eight properties are at high risk. The high risk attributed to the properties was mainly due to the precariousness of the existing slope protection structures in the area under study, that associated with factors such as high waterproofing rate, irregular constructions, among other factors. Thus, to guarantee the habitability of the properties analyzed, it is evident the need for corrective measures in the situations encountered, in addition to public policies for controlling the occupation of risk areas.

24
  • VANESSA DE SOUZA BATISTA
  • POTENTIAL OF THE USE OF LIMESTONE MINING WASTE FOR STABILIZATION OF EXPANSIVE SOILS

  • Leader : OLAVO FRANCISCO DOS SANTOS JUNIOR
  • MEMBRES DE LA BANQUE :
  • ANA PATRICIA NUNES BANDEIRA
  • MARIA DEL PILAR DURANTE INGUNZA
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • RICARDO NASCIMENTO FLORES SEVERO
  • Data: 15 déc. 2021


  • Afficher le Résumé
  • POTENTIAL OF THE USE OF LIMESTONE MINING WASTE FOR STABILIZATION OF EXPANSIVE SOILS

25
  • JEFFERSON TEÓFILO FERREIRA DA SILVA
  • EVALUATION OF THE DEGRADATION OF GEOTEXTILES SUBMITTED TO EXPOSURE BY ULTRAVIOLET RADIATION IN THE MUNICIPALITY OF MOSSORÓ / RN
  • Leader : FAGNER ALEXANDRE NUNES DE FRANCA
  • MEMBRES DE LA BANQUE :
  • ENIO FERNANDES AMORIM
  • FAGNER ALEXANDRE NUNES DE FRANCA
  • RICARDO NASCIMENTO FLORES SEVERO
  • Data: 17 déc. 2021


  • Afficher le Résumé
  • It is essential that geosynthetics have a good durability when applied in the most diverse environments. Thus, it is important to evaluate how the material behaves in terms of its resistance to different degrading agents. The present research aimed to study the levels of degradation, carrying out tests, with variable specimen sizes, in which they were exposed, to ultraviolet radiation for a predetermined time. A woven geotextile was used, exposed to natural aging tests, in the municipality of Mossoró-RN. The material will be exposed for a period of approximately 3 months, with samples being obtained for the times of 1, 2 and 3 months for each type of test. The degradation test took place outdoors, using a table topped with naval plywood, in which samples with different sizes and thicknesses were placed. At the end of each determined period of time, samples were taken and prepared in specimens of thickness 50 and 200 mm, with lengths of 600 and 1000 mm, totaling 4 different specimen sizes, to carry out tests to determine the geotextile weight and unconfined tensile strength. The study proved to be of great importance for obtaining parameters, regarding the exposure of the material given a brief period of time, concluding that the geotextile presents good functionality in its use, in works that demand a certain amount of time for the installation of the material.

26
  • RAILTON RAWLYSON DANTAS CAMARA
  • APPLICATION OF THE DISCRETE ELEMENT METHOD ON THE STUDY OF THE CYCLIC RESPONSE OF A SEMI-INTEGRAL BRIDGE ABUTMENT


  • Leader : YURI DANIEL JATOBA COSTA
  • MEMBRES DE LA BANQUE :
  • LEONARDO HENRIQUE BORGES DE OLIVEIRA
  • WILSON CARTAXO SOARES
  • YURI DANIEL JATOBA COSTA
  • Data: 28 déc. 2021


  • Afficher le Résumé
  • Integral and semi-integral bridges are alternatives for conventional bridges, which routinely present problems associated with expansion joints and bearings. However, the cyclic lateral displacements of the superstructure, induced by temperature variations, lead to a complex interaction between the backfill and the abutment of an integral or semi-integral bridge, which requires in-depth assessment of the behavior of these bridges. In this research, ISSS’s Rocky software was used to build a computational model based on the discrete element method (DEM) for investigating the response of a granular backfill to the cyclic displacements a semi-integral bridge abutment located in Texas, USA. In order to bring the stresses and strains in the numerical model to the same level of the stresses and strains developed in the bridge abutment in the field, the numerical simulations were carried out with a gravitational acceleration equal to 3 g. The cyclic sequence of imposed lateral displacements was chosen to simulate the completion of the bridge in the summer. The prescribed lateral displacement magnitude of ± 5 mm was selected to represent the annual cyclic response of the bridge. Results indicated an increase in the lateral earth pressure coefficient on the abutment’s face and an increase in  settlements on the backfill surface with the cycles. A good agreement was found between the results obtained in the present work and results obtained from simulations performed for the same bridge using the finite element method (FEM). Additional DEM simulations were performed to investigate the influence of the lateral displacement amplitude, the completion season of the bridge construction and the type of abutment movement. Variations of the lateral displacement amplitude and variations of the abutment movement type were found to play a significant influence on lateral earth pressures on the abutment wall and on vertical displacements of the backfill soil, while variations of the completion season of the bridge construction had little influence on the results.

2020
Thèses
1
  • ANDERSON DANTAS DE MORAIS
  • GEOTECHNICAL PROPERTIES OF THE BARREIRAS
    FORMATION SEDIMENTS AND ESTABILITY ANLYSES IN
    CLIFFS CONSIDERING UNSATURATED SOIL CONDITION: CASE

    STUDY IN BARRA DE TABATINGA / RN.

  • Leader : OLAVO FRANCISCO DOS SANTOS JUNIOR
  • MEMBRES DE LA BANQUE :
  • FAGNER ALEXANDRE NUNES DE FRANCA
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • OSVALDO DE FREITAS NETO
  • RICARDO NASCIMENTO FLORES SEVERO
  • Data: 2 mars 2020


  • Afficher le Résumé
  • In the state of Rio Grande do Norte exists outcrops of cliffs that belongs to the Barreiras Formation, which cities and infrastructure works are developed on. In this region, mass movements are reported in relevant proportions, especially in rainy season. The development of coastal cities and the growing tourism market in this area has demanded the study of the cliffs and their material, so that new engineering projects are safely implemented. The aims of this work were to study the geotechnical properties of the Barreiras Formation soils that make up the Barra de Tabatinga / RN beach cliff and to evaluate the stability of the cliff from the deterministic point of view. The studied cliff was divided into three predominant soils, which are located at the base (AM-01), middle (AM-02) and top (AM-03) layers. In these soils, were performed characterization tests (geotechnical, chemical and mineralogical), tests to determine the soil-water retention curve, permeability tests, triaxial and diametral compression tests under saturated and unsaturated conditions. Considering the Unified Soil Classification System (SUCS), samples AM-01, AM-02 and AM-03 were respectively classified as similar in behavior to silt-clay sand (SM-SC), silt sand (SM) and poorly graded sand (SP). The chemical analysis identified oxides of silicon, aluminum and iron in higher percentages. Regarding the mineralogical analyzes, the presence of Quartz and Kaolinite were detected in all samples. Samples AM-01 and AM-02 showed bimodal soil-water retention curves, unlike the top sample, which presented unimodal fit. In addition, all of them presented close to zero cohesion and angle of friction around 30° in the saturated condition. However, when unsaturated, the strength parameters increased considerably, especially the cohesion. In unsaturated condition, the top soil is the least shear and tensile strength. Concerning stability analyzes, these were performed in Slope / W (Geostudio, 2012) considering three different hypotheses: fully saturated cliff (hypothesis 01); totally dry cliff (hypothesis 02) and the water infiltration on cliff top (hypothesis 03) through numerical modeling in Seep / W (Geostudio, 2012). Hypothesis 03 attempted to approach the actual critical condition, trying to consider the effect of rain on cliff stability. Therefore, it was concluded that for the considered rain, the cliff rupture is characterized, since FS = 1 is reached. Moreover, it was observed that the rupture occurs completely through the top layer material and can reach depths of up to 8 meters. 

2
  • TIAGO FEITOSA GONDIM
  • Geotechnical application of mining residue in cover system of waste landfill.

  • Leader : MARIA DEL PILAR DURANTE INGUNZA
  • MEMBRES DE LA BANQUE :
  • MARIA DEL PILAR DURANTE INGUNZA
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • OSVALDO DE FREITAS NETO
  • RICARDO NASCIMENTO FLORES SEVERO
  • Data: 19 mars 2020


  • Afficher le Résumé
  • The use of mining residues within production chains, such as civil construction, is an important environmental solution for mining activities in Brazil. Researchers have shown that different types of mining residues can be incorporated into some types of geotechnical works, fulfilling the function of hydraulic barrier. In this scenario, the use of scheelite residue in environmental geotechnics works could be an environmentally sustainable solution for this material. This work aims to evaluate the technical viability of using scheelite mining residues as a compacted coating with hydraulic barrier function in waste landfill covering systems. Physical characterization, compacting, hydraulic conductivity on rigid and flexible wall permeameters, XRF/XRD and SEM and erodibility tests were performed on four materials formed by mixing two residues generated during the scheelite processing at the Brejuí Mine in Currais Novos/RN. During the hydraulic conductivity tests, it was observed that, in the samples that contained a higher percentage of fine particles (< 0,075 mm), there was a progressive decrease in the permeability of the compacted material, from 1,76x10 -6  to 2,18x10 -8  m/s, but not necessarily a significant variation in the density or porosity, indicating that the incorporated fines filled the voids of the larger particles increasing the flow tortuosity. The decrease in permeability can be explained by morphological factors specific to the material used, indicating that its behavior differs from the expected behavior for a soil. The F100 and F75G25 samples proved to be viable for the intended application (hydraulic barrier in landfill covering), meeting international normative requirements. The other composites (F50G50 and F25G75) could be applied for other purposes within a waste landfill: as regularization and/or protection layers. The obtained results demonstrate the technical viability of the intended use of the material.

3
  • ALISSON CABRAL BARRETO
  • Technical Performance of Mixtures of Different Types of Soils with CDW for Use in Paving Works.

  • Leader : ENIO FERNANDES AMORIM
  • MEMBRES DE LA BANQUE :
  • ENIO FERNANDES AMORIM
  • MARIA DEL PILAR DURANTE INGUNZA
  • RENATO SAMUEL BARBOSA DE ARAÚJO
  • Data: 27 mars 2020


  • Afficher le Résumé
  • The growth of the urbanization process that has occurred in the last decades has caused an increase in civil construction and, consequently, an increase in the generation of waste arising from this process. The waste from construction and demolition of civil works (CDW) represents the majority of the volume of waste that is generated in large urban centers, and it is necessary that an appropriate destination be carried out to mitigate the environmental impacts and the social problems they cause. Based on these factors, several researches were carried out in different
    regions of Brazil and the world in order to use this residue as an alternative material in paving works. In this context, this work aims to analyze the use of CDW associated with different types of soil from the state of Rio Grande do Norte, aiming at its use in paving works. For this, the percentages of CDW of 25%, 50% and 75%, by mass, were added to the soil, in order to verify the benefit that this increase can cause in the characteristics of the materials. The experimental program was carried out using CDW samples obtained by a private company, and soil samples extracted from three major regions in the state of Rio Grande do Norte. The laboratory investigation methods were based on physical characterization, compaction, CBR and grain break analysis tests. The results obtained show that depending on the percentage of residue and the type of soil, the increase of CDW to the soil causes the CBR values to rise and improve the properties of the samples. Thus, the replacement of part of the natural aggregate by CDW is a potential alternative for application in pavement works.

4
  • ANA LÍGIA PESSOA SAMPAIO
  • PROPOSAL OF AN EARTHBAG CONSTRUCTION SYSTEM WITH INCORPORATION OF CASSAVA WASTE WATER.

  • Leader : WILSON ACCHAR
  • MEMBRES DE LA BANQUE :
  • WILSON ACCHAR
  • LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • CLAWSIO ROGERIO CRUZ DE SOUSA
  • VAMBERTO MONTEIRO DA SILVA
  • Data: 27 mars 2020


  • Afficher le Résumé
  • The Brazilian territory is not uniform and has specific bioclimatic contexts for each region, categorized into eight bioclimatic zones with different parameters and conditions to achieve comfort, however they are not taken in account when thinking about new materials and construction techniques in the country. The Bioclimatic Zone 07, which cover part of the Brazilian savanna and savannah in which walls with high thermal mass are recommended, and 08, which comprises a good part of the North of Brazil and the coast of the Northeast, with the suggestions of
    light constructions, cross the state of Rio Grande do Norte, but there are no options for building systems that meet the recommendations of Zone 07 in the civil engineering segment. Thinking about it, techniques that allow the use of soil for construction, very abundant, still guaranteeing high thermal mass and other thermo-acoustic properties without compromising cost would be a great solution. At the same time, some qualities observed in the study of the substitution of water by cassava waste water, the residue of washing cassava, usually discarded, indicate its potential to be applied in blocks. In this scenario, this work goes through the construction system proposed from two perspectives: regarding the bioclimatic context, focusing on climatic conditions; and as for the properties of construction materials, studying their shape, constitution, resistance and even the treatment of their surfaces. Therefore, the aim of this work is to propose an earth construction system based on Brickeradobe with incorporation of cassava waste water instead of tap water. It starts from a reference study and experimental research in the laboratory in order to characterize the materials in terms of their properties, not only physical-mechanical, but also chemical- mineralogical, in which the form, the casing and the composition, the latter being defined through the formulation proposals and after the mechanical tests have been carried out. Among the main tests carried out, we did resistance compression tests at 07 and 28 days, water absorption by capillarity and thermal conductivity at 28 days for soil and water (SA), soil and manipueira (SM), soil with 10% cement and water (CA) and soil with 10% cement and manipueira (CM) cmpositions. With all formulations showing results of compressive strength above 1 MPa, with three of them above 2 MPa, and the composition with only soil and manipueira obtaining resistance values similar to the cement and water formulation, the potential of manipueira as a catalyst by favoring some cationic exchanges and improving the workability of the material, facilitating its compaction and generating denser blocks. Subsequently, two houses with 1m² of internal area and 1.50 m in height were built at UFRN, in which execution time, costs and their thermo-acoustic performance were measured through monitoring. Regarding the thermal properties, the Thermal Resistance, Thermal Transmittance, Solar Callus Factor and Thermal Delay of the blocks isolated and inserted in the system were also evaluated, obtaining excellent performance, while still being about 20% cheaper than the conventional masonry system, but requiring more physical effort.

     

5
  • WESLLEY EUNATHAN FERNANDES LIMA
  • Proposition of an educational scenario for teaching BIM in a blended learning perspective. 

  • Leader : REYMARD SAVIO SAMPAIO DE MELO
  • MEMBRES DE LA BANQUE :
  • ANA REGINA MIZRAHY CUPERSCHMID
  • JOSYANNE PINTO GIESTA
  • REYMARD SAVIO SAMPAIO DE MELO
  • Data: 10 juin 2020


  • Afficher le Résumé
  • Given the demand for professionals with Building Information Modelling (BIM) skills, the teaching of this paradigm in civil engineering undergraduate courses is no longer an option and becomes a necessity.In addition, the insertion of active learning methodologies becomes important in view of the mandatory insertion as recommended by the National Curriculum Guidelines for the Undergraduate Engineering Course.The aim of this research is to propose an educational scenario for BIM teaching from the perspective of blended learning.For that, Design Science Research was adopted as a research method, through practical experience in a course in the civil engineering curriculum of the Federal University of Rio Grande do Norte (UFRN), where BIM was inserted through two modalities of blended learning:station rotation and flipped classroom. In this sense, three versions of the educational scenario were developed, in each of these versions there was a refinement in relation to the previous version. The development of this educational scenario contributes to the teaching of BIM and blended learning courses linked to AEC and contributed to the strengthening of the teaching-learning process of students through an active learning.

6
  • ROBSON RIBEIRO
  • NON-LINEAR SOIL-STRUCTURE INTERACTION OF A PILED RAFT WIND TURBINE FOUNDATION: EFFECTS ON THE MODAL AND DYNAMIC ANALYSIS ON A NREL 5 MW WIND TURBINE

  • Leader : JOSE NERES DA SILVA FILHO
  • MEMBRES DE LA BANQUE :
  • DANIEL NELSON MACIEL
  • JOSE NERES DA SILVA FILHO
  • LUIZ CARLOS DE ALMEIDA
  • Data: 26 juin 2020


  • Afficher le Résumé
  • Wind turbine support structures are dynamically sensible structures. With the rotor diameter rise, in order to increase energy production, this situation tends to get more critical, giving rise to the needing of more accurate studies regarding system’s dynamic behaviour. It is known that, due to previous researches and design practice, soil-structure interaction plays a major role in the wind turbine natural frequencies of vibration, as well as in the stresses and displacements when applying dynamic operational and wind loads. Considering this scenario, the present research seeks to study non-linear soil-structure interaction models for analysing wind turbine towers. It was used a wind turbine model from National Research Laboratory (NREL) with nominal power of 5 MW and geotechnical data of Wind Power Plant Miassaba 3, located in the Rio Grande do Norte State. Four different SSI models were used: an analytic model with the expressions from DNV (2002); non-linear numerical FEM model (ABAQUS) using p-y, t-z and Q-z load transfer curves from API (2005); non-linear numerical FEM model (ABAQUS) calibrated with pile load test from Miassaba’s construction site; non-linear FEM model (ABAQUS) with elasto-plastic constitutive model (Mohr-Coulomb failure criteria) also calibrated with the same pile load tests. The results shows a discrepancy between analytical and numerical models, where the former provides larger values of global foundation stiffness, the differences being more critical for extreme load case scenarios. This fact brings attention towards to the needing of non-linear models for the dynamic behaviour assessment, in order to have more reliable foundation design. Additionally, the effects of SSI were evaluated in term of dynamic amplificatory factor of 1P load, which revealed a 16% and 20% foundation load increasing, respectively, in overturning moment and horizontal force.

7
  • OLÍMPIA LOURES VALE PUJATTI
  • PARAMETRIC ANALYSIS OF DISTRIBUTION OF THE BENDING MOMENT AND SUPPORT REACTIONS DUE TO THE LIVE LOAD IN SKEWED BRIDGES OF DECKS WITH MULTIPLE GIRDERS AND SLABS

  • Leader : JOSE NERES DA SILVA FILHO
  • MEMBRES DE LA BANQUE :
  • JOSE NERES DA SILVA FILHO
  • JOÃO DA COSTA PANTOJA
  • RODRIGO BARROS
  • Data: 10 juil. 2020


  • Afficher le Résumé
  • The structural analysis of the bridges with skew longitudinal geometry presents greater complexity when compared to a straight bridge. Therefore, there is a 0shortage of research on the subject both nationally and internationally. The objective of this work was to perform a parametric study of the bending moment distribution according to the moving load and the support reactions in skew bridges made with grid and slab. To reach this purpose, numerical models were constructed for structural systems of bridges with trays in beams molded in loco and in slab, using the Finite Element Method using the computer program CSiBridge v21, in order to acheive: (a) the influence of the addition of supporting and intermediate crossbeams on the bending moment distribution and on the support reactions of skewed bridges with multiple grids and, (b) the distribution of bending moments and support reactions on the skewed bridges with slabs. The analysis proposal recommended by the American Association of State Highway and Transportation Officials (AASHTO LRFD, 2017) was also applied, in order to compare the results with those obtained in the modeling. The results showed in the situations of the orthogonal bridge with longitudinal girders a symmetrical distribution of the bending moment distribution factor (BMDF’s) due to the mobile load. In all the situations studied on the bridges with side members, with the introduction of the angle of skewed, changes occurred in the distribution of the bending moments. The global analytics of the support reactions due to the mobile load showed that in the orthogonal bridge models, the reactions were evenly distributed, presenting equal values for the supports positioned at the same distance in relation to the central axis. The introduction of obscurity generated an uneven behavior of the reactions, with an increasing trend towards the obtuse angle. For some models, the percentage variation between the support close to the obtuse angle and the support used as a reference, close to the acute angle reached almost 50%. In the hidden bridges in slab, in all the cases analyzed, the ix obscurity generated a significant reduction in the reaction of the support close to the acute angle, with an increasing trend towards the obtuse angle, presenting itself higher in the support closer to the obtuse angle. When the behavior of the bending moment was analyzed, it was also possible to observe a change in its behavior with the introduction of skews. In general, the Mx and My moment, in module, became larger close to the obtuse angle. Finally, the percentages and variations observed for the slab model were much higher than those observed in the grid models.

8
  • MARIA CECÍLIA DE SOUZA E SOUZA
  • APPLICATION OF BIM IN THE INFRASTRUCTURE SECTOR: STUDY IN A WATER AND SEWAGE COMPANY OF THE RN.

  • Leader : JOSYANNE PINTO GIESTA
  • MEMBRES DE LA BANQUE :
  • HEITOR DE ANDRADE SILVA
  • JOSYANNE PINTO GIESTA
  • MAX LIRA VERAS DE ANDRADE
  • REYMARD SAVIO SAMPAIO DE MELO
  • Data: 15 juil. 2020


  • Afficher le Résumé
  • The lack of diverse infrastructures (transport, sanitation, energy, etc.) in Brazil is known and the public sector is the largest owner of this type of enterprise. Infrastructure is considered fundamental for a country's productivity and economic development, it integrates markets and connects economic agents, helps reduce costs and the flow of information. In most countries, investment in infrastructure is on the list of political and economic priorities. However, Brazil is one of the countries that invests less in the sector: the current contribution is around 2% of GDP. China and India apply rates of 7% and 5.5% of GDP. The United States invests about 2.5% only with maintenance in water and transportation. Besides being scarce and poorly applied, part of the Brazilian investment ends up withheld in paralyzed works. According to the Ministry of Planning, Development and Management, in 2017, 18.5% of the paralyzed projects were in the infrastructure sector. BIM may be a solution for the infrastructure sector, given its characteristics in terms of assertiveness, accuracy, compatibility and extraction of reliable information. Recognizing the relevance of BIM, the federal government recently published Decree nº. 9,983, of August 22, 2019, which provides for the National Strategy for Dissemination of Building Information Modelling and established the Strategy Management Committee and began to require the adaptation of Brazilian public sectors to the BIM paradigm. Studies point out that the implementation of BIM in infrastructure has occurred in several countries ¬– especially in the USA, with emphasis on studies in the area of transportation ¬– and the existence of a gap when it comes to infrastructure of public services, specifically in water supply and sewage systems. In this study, no nationwide research on BIM in infrastructure was identified, as well as a characterization made in the public agencies of the RN that showed the almost non-existent use of BIM by the sector. Faced with this situation, the interest and importance of analyzing and evaluating the applicability of the Construction Information Modelling in infrastructure projects arises, given that, in Brazil, this type of undertaking is under the responsibility of public authorities and has a strong influence on the economy and development of a nation. This master's thesis aims to develop a method for implementing BIM in the infrastructure sector of public services, specifically in water supply and sewage systems. The research method used is the Design Science Research which had as its final product the proposition of a method (artefact), formed by a set of guidelines, which guides and orders the adequacy of the sector of projects studied to BIM. The proposed method is the greatest and most important contribution of this work, with the systematic review of the literature, which addresses the applicability of BIM in the infrastructure sector, and a diagnosis on the use of BIM in public agencies (responsible for infrastructure enterprises) in the RN. 

9
  • SARA DE OLIVEIRA MARQUES LUNA
  • INCREMENTAL ANALYSIS INCLUDING SHRINKAGE, CREEP AND CONSTRUCTIVE EFFECTS ON REINFORCED CONCRET TRANSFER GIRDER

  • Leader : RODRIGO BARROS
  • MEMBRES DE LA BANQUE :
  • HIDELBRANDO JOSE FARKAT DIOGENES
  • JOSE NERES DA SILVA FILHO
  • RODRIGO BARROS
  • Data: 17 juil. 2020


  • Afficher le Résumé
  • The numeric modeling and methods of measurement applied to reinforced concrete structures could differ from the buildings’ real conditions. The effects of staged constructive method, in which loads are positioned on the floors bellow, and the time strains, such as creep and shrinkage when taken into account in conventional structural analysis, occur in a simplified manner. For hyperstatic structure under high loads cases - as is the case of transition beams - are even more relevant the mentioned effects, which could be crucial for ensuring the structural safety. Therefore, it is indispensable to apply the incremental analysis method and knowing the consequences to the stress and strains caused by construction loads and time strains. The aim of this study is modelling a 10- storey standard building on the SAP 2000 software containing a hyperstatic transfer girder on the ground floor. It will be considered the shrinkage, creep and constructive effects, analyzing a 2D gantry, trying to identify how these deformations influence the values of maximum moments in the beam in question. The main results comprises an increase in the moment of transition change as a whole, as well as displacements. The percentage increases between the use of conventional and incremental analysis were higher for the more paved gantries, however, a more sudden variation of effort occurs when the building has lower heights and more floors are added.

10
  • PEDRO HENRIQUE DOS SANTOS SILVA
  • NUMERICAL ANALYSIS OF A SEMI-INTEGRAL BRIDGE ABUTMENT UNDERGOING CYCLIC LATERAL DISPLACEMENTS

  • Leader : YURI DANIEL JATOBA COSTA
  • MEMBRES DE LA BANQUE :
  • YURI DANIEL JATOBA COSTA
  • CARINA MAIA LINS COSTA
  • JORGE GABRIEL ZORNBERG
  • JOSÉ ANTÔNIO SCHIAVON
  • Data: 18 sept. 2020


  • Afficher le Résumé
  • Integral abutment bridges (IABs) and semi-integral abutment bridges (SIABs) are structural systems built without thermal expansion joints at the abutments. In view of this peculiar characteristic, the abutment undergoes combined movements of translation and rotation due to expansion and contraction of the superstructure caused by temperature variations. Such behavior favors the increase of lateral earth pressures on the abutment and vertical displacements of the backfill surface, due to a complex soil-structure interaction mechanism associated with the cyclic lateral displacement of the abutment. The purpose of the present investigation is to assess the effects of cyclic lateral displacements on the response of the backfill-abutment system of a SIAB. A finite element model was developed and validated based on field data from an instrumented SIAB located in the State of Texas, USA. Field data were obtained from pressure cells installed against the abutment, and from temperature sensors positioned under the bridge superstructure. The soil stress-strain behavior was represented by a hyperbolic constitutive model, and the effects of expansion and contraction of the superstructure were given by prescribed horizontal displacements estimated from the temperature variations measured by the temperature sensors. Predictions with the proposed numerical model were found to produce a good match with the field data. After the validation phase, numerical simulations were performed to predict the daily and annual response of the backfill- abutment system, as well as to analyze the influence of the completion season of the bridge construction, the pile foundation stiffness, and the displacement magnitude on the response of the system. The lateral earth pressures on the abutment and the vertical displacements of the backfill surface increased with cycles. Earth pressures presented a nonlinear distribution along the abutment height. The largest settlements occurred near the backfill-abutment interface and decreased with increasing distance from the abutment. A heave was formed at a certain distance from the abutment. Earth pressures tended to reach a steady state after some cycles while vertical displacements were not found to stabilize. The completion season of the bridge construction influenced the vertical displacements but not the earth pressures. Earth pressures and vertical displacements were not affected by the pile foundation stiffness. The displacement magnitude influenced in both the earth pressures and the vertical displacements.

11
  • DÉBORA PATRÍCIA BATISTA DA ROCHA
  • LIFE CYCLE ASSESSMENT OF ARTIFICIAL LIGHTWEIGHT AGGREGATES PRODUCED WITH INDUSTRIAL WASTE AND
    RED CLAY (NORTHEAST/BRAZIL)

  • Leader : MARCOS ALYSSANDRO SOARES DOS ANJOS
  • MEMBRES DE LA BANQUE :
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • LUCIANA DE FIGUEIREDO LOPES LUCENA
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • CLAUDIA COUTINHO NÓBREGA
  • Data: 9 oct. 2020


  • Afficher le Résumé
  • The adoption of alternative materials has become an increasingly constant practice in civil construction in the search for sustainable solutions for the conservation of natural resources. The reuse of industrial waste in new construction materials has aroused growing interest in environmental impacts of the production of recycled
    aggregates to replace conventional aggregates. To this end, this study sought to measure the environmental impacts resulting from the production of artificial lightweight aggregates produced with sugarcane biomass ash (SCBA) and red clay from the Northeast of Brazil through the Life Cycle Assessment (LCA) methodology. For this, an industrial production proposal was prepared with specification of the stages and equipment, with the possibility of being adapted to different regions of Brazil. The LCA procedure followed four main steps, prescribed by the ABNT ISO 14040:2009 and ABNT ISO 14044:2009 standards: definition of objective and scope, inventory analysis, impact assessment and interpretation. The system boundary went from the cradle to the gate level and includes the stages of extraction, collection and processing of raw materials and production of lightweight aggregates. The environmental impacts were evaluated for three compositions of the artificial lightweight aggregate (pure clay, 50% replacement and 90% SCBA). The compositions were studied in three locations of the factory: Itajá/RN, Goianinha/RN and Parnamirim/RN. The inventory data were processed using OpenLCA 1.10 software using the CML 2001 non baseline method and midpoint approach. The impact categories studied were: acidification, eutrophication, global warming, human toxicity, ozone depletion, photochemical ozone formation, terrestrial ecotoxicity, freshwater ecotoxicity and marine ecotoxicity. The results showed that
    the use of SCBA in the composition of lightweight aggregates allowed a reduction of up to 87.21% in the use of red clay as a natural resource, in two of the three scenarios analyzed. The aggregate compositions using SCBA showed lesser environmental impacts (except in the category of global warming) compared to the composition of pure clay in scenarios where the location of the factory is close to where the waste is obtained. The transport stages influenced significantly in all impact categories due to the use of fossil fuel (diesel) and the results are very sensitive to transport distances. The stage of burning light aggregates is highlighted in the global warming category. This study clearly showed that lightweight aggregates with the use of industrial waste can contribute to the reduction of environmental impacts during their production. The results can support decision-making processes and the development of similar LCA studies in lightweight artificial aggregates.

12
  • PALOMA COLMANA MARTINS DE FIGUEIREDO
  • THE INFLUENCE OF VERTICAL SPACING BETWEEN REINFORCEMENT LAYERS ON THE GEOSYNTHETIC REINFORCED SOIL DISPLACEMENT OF BRIDGE-SUPPORTING WALLS

  • Leader : CARINA MAIA LINS COSTA
  • MEMBRES DE LA BANQUE :
  • ANA PATRICIA NUNES BANDEIRA
  • CARINA MAIA LINS COSTA
  • LUCIANE MARCELA FILIZOLA DE OLIVEIRA
  • YURI DANIEL JATOBA COSTA
  • Data: 19 oct. 2020


  • Afficher le Résumé
  • The Geosynthetic Reinforced Soil (GRS) bridge-supporting walls are structures in which the bridge abutment is supported directly by the reinforced fill, allowing the reinforced soil structure to function both as a retaining element and a foundation one. The advantages associated to the use of retaining walls includes cost reduction, rapid construction, capability of supporting differential settlements and good seismic performance. However, due to being a fairly recent method, there are scarce studies published regarding this topic. Especially in relation to the effect of vertical spacing between reinforcements layers, considering a constant ratio of geosynthetic stiffness (J) to the vertical spacing (Sv). This research investigated using numerical simulations the influence of the vertical spacing between geosynthetic layers on the reinforced soil mass performance for the same J/Sv ratio. Small values of vertical spacing were assumed, according to the typically used distances in GRS bridge-supporting walls. The finite element method computer software PLAXIS 2D (2016 version) was used to perform the numerical simulation. The validation of the numerical model was made using results of laboratory tests performed at The University of Texas at Austin, USA. The tests were conducted using a rigid box of large dimensions, in which the frontal wall allowed lateral movements. Thereby, it was possible to simulate displacements from the frontal side of the real retaining structure at the bridge abutment in the field. The numerical simulations used to parametric analysis were performed by variating the vertical spacing, the reinforcement stiffness, the height and the length of the reinforced soil. The results indicated that the increase in the stiffness and decrease in the vertical spacing of the geosynthetic layers led to smaller lateral displacements and smaller settlements. Nevertheless, the decrease in the vertical spacing was perceived as a more significant aspect than the reinforcement stiffness. To smaller values of the J/Sv ratio, the modifications of the vertical spacing caused different displacements however, to larger values of that same ratio, changes were not noticeable.

13
  • KAIO GEOVANNE DE MEDEIROS DANTAS
  • Study of local second order effects on shear walls of structural masonry buildings

  • Leader : JOEL ARAUJO DO NASCIMENTO NETO
  • MEMBRES DE LA BANQUE :
  • DANIEL NELSON MACIEL
  • GUILHERME ARIS PARSEKIAN
  • JOEL ARAUJO DO NASCIMENTO NETO
  • Data: 23 oct. 2020


  • Afficher le Résumé
  • The present study consisted of the evaluation of local second order effects on unreinforced shear walls in structural masonry through a numerical approach using the Finite Element Method. For this purpose, an adaptation was made to the equivalent frame model to simulate the out-of-plane response of selected shear panels on two storeys of a building. The validation of the new model was performed by comparing its results with those obtained from an experimental model for slender walls in which a flexion out-of-plane of the walls was mobilized. The shear walls were modeled in three configurations: complete shear panels under loads applied in full extension; isolated columns; and complete shear panels under the application of loads separately in each column. The analysis considered the magnitude of the displacement of the panels, the influence of the columns, as well as the second order moments caused by the models’ geometric nonlinearity. Finally, verifications in the design of panels and isolated columns were carried out using the methodologies prescribed in the Brazilian standards NBR 15961-1: 2011, NBR 16868-1: 2020, and in the British standard BS 5628: 2005, with subsequent comparison with the results obtained from numerical modeling. The analysis of the results showed the influence of the lateral support on the panels’ stiffness, and highlighted the importance of considering the local second order effects in panels’ design, since the required values of compressive strength increased substantially when considering these effects. In addition, it was possible to observe the efficiency of the model developed in the proposed approach, since it presented similar results to those resulting from the prescriptions of NBR 16868-1.

14
  • JEMIMA TABITA FERREIRA DE SOUSA
  • Não consta.

  • Leader : MARCOS ALYSSANDRO SOARES DOS ANJOS
  • MEMBRES DE LA BANQUE :
  • ENIO FERNANDES AMORIM
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • VALTENCIR LUCIO DE LIMA GOMES
  • Data: 29 oct. 2020


  • Afficher le Résumé
  • Não consta.

15
  • EWERTON WEYNEMI CAVALCANTE DOS SANTOS
  • Não consta.

  • Leader : FAGNER ALEXANDRE NUNES DE FRANCA
  • MEMBRES DE LA BANQUE :
  • ENIO FERNANDES AMORIM
  • FAGNER ALEXANDRE NUNES DE FRANCA
  • FERNANDO HENRIQUE MARTINS PORTELINHA
  • JOSE IVAN DE MEDEIROS
  • Data: 30 oct. 2020


  • Afficher le Résumé
  • Não consta.

16
  • TENÓRIO JOSÉ DE BRITO
  • USE OF GEOTECHNOLOGIES APPLIED IN THE FLOOD MAPPING IN SCENARIOS OF LAND USE: A CASE STUDY ON NEIGHBORHOOD ALTO SUMARÉ - MOSSORÓ/RN

     

  • Leader : VENERANDO EUSTAQUIO AMARO
  • MEMBRES DE LA BANQUE :
  • ADA CRISTINA SCUDELARI
  • ALEXANDRE BERNADINO LOPES
  • VENERANDO EUSTAQUIO AMARO
  • Data: 30 oct. 2020


  • Afficher le Résumé
  • Floods have become frequent events in urban spaces around the world and have been analyzed both as a consequence of events related to climate change and disorderly changes in urban space. In the Municipality of Mossoró/RN, there was an accelerated process of urban occupation in the last 10 years, fostered by the Federal Government program Minha Casa Minha Vida. Even though it is a program where the projects precede planning under good engineering practices, in which the implementation of drainage infrastructure is observed and, mandatorily, require evaluation and seal of the municipality authority, problems of flooding occurred in Alto Sumaré neighborhood, treated as a study area. In the analysis of urban growth, remote sensing images available in Google Earth Pro were used and treated in Geographic Information System (GIS) environment. This analysis allowed estimating for the Alto Sumaré neighborhood the percentage of urban sprawl of 180.75% between 2010 and 2017 and 112.75% between 2017 and 2019. The elaboration of Digital Surface Model (DSM) calibrated with control points in the field, based on planialtimetric surveys techniques with Global Navigation Satellite System (GNSS) and referred to the Brazilian Geodesic System, allowed the evaluation of flooding points. The results indicated that the drainage devices installed in the residential developments of the Alto Sumaré neighborhood were guided by the concept of incomplete cushioning, because most of the damping ponds implanted do not have bottom discharger. The absence of this equipment promoted a false safety effect, as it imposes rapid flow when the volumes of the ponds are reached, which increases the contribution area and, therefore, the flow downstream, causing flooding. Accumulation volumes for recurrence times of 5, 10 and 25 years, appreciating the contribution sub-basins of each pond and low topographies identified in the DSM, indicated greater accumulated volume than accumulation capacity reserve at pond Cidade Jardim 1 and Res. Monte Olimpo, for instance, in the 3 recurrence times. Thus, the calculations show that the damping capacity of most ponds is insufficient.

17
  • ITAMAR GONÇALVES DA COSTA
  • EVALUATION OF THE RELATIONSHIP BETWEEN DEFORMATION MODULE AND CBR OF A COMPACTED PAVEMENT

  • Leader : OLAVO FRANCISCO DOS SANTOS JUNIOR
  • MEMBRES DE LA BANQUE :
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • OSVALDO DE FREITAS NETO
  • RAIMUNDO LEIDIMAR BEZERRA
  • Data: 30 nov. 2020


  • Afficher le Résumé
  • This work presents a study on the relationship between deformation module (E) and the California Bearing Ratio (CBR) of a compacted pavement composed of a base layer of well-graded Stony soil overlying a compacted subgrade formed by poorly graduated clay sand. an area located on the north coast of Rio Grande do Norte. The objective of the work is to find out if there is a linear relationship between the deformation module and the CBR by performing in situ and laboratory tests as well as to compare the deformation module obtained with the equation of the international standard NLT 357/98 and the same module obtained by the theory equation (Shell, 1985). For this, field tests of static load test (PCE) were performed on a plate to obtain the deformation module and laboratory tests to obtain the CBR value of the soil. By analyzing the results it was possible to conclude that there is no linear relationship between the deformation module and CBR, with the deformation module presenting results compatible with other current international standards while the CBR values present homogeneous and slightly variable values in relation to their average differently the values of the deformation module that are more variable. The value of the deformation module is compatible with that obtained by the international standard and, using CBR in the methodology of (Shell, 1985), it presents a different value of deformation module.

2019
Thèses
1
  • MANOEL LEANDRO ARAÚJO E FARIAS
  • Uplift behavior of an instrumented helical pile subjected to cyclic loading in sandy soil.

  • Leader : YURI DANIEL JATOBA COSTA
  • MEMBRES DE LA BANQUE :
  • JOSE NERES DA SILVA FILHO
  • WILSON CARTAXO SOARES
  • YURI DANIEL JATOBA COSTA
  • Data: 14 févr. 2019


  • Afficher le Résumé
  • In this paper, the pull-out load behavior of instrumented helical piles subjected to cyclic loading in sandy soil is evaluated. The used pile had three bearing plates and was instrumented with resistance electric strain gauges in three sections along the shaft. Three pull-out load tests were performed, two with quasi-static cyclic loading and one with static loading, to verify the effects of cyclic loading. The tests with quasi-static loads were made with different values of average cyclic load and load amplitude. The results showed a great influence of the way in which the load increments were used due to the densification and disturbance of the surrounding soil. The accumulated displacements tended to stabilize after the 10th cycle, low rates of mean displacement accumulation were not obtained and the number of cycles before failure showed to be dependent on the average load and cyclic amplitude. With the instrumented sections, a reduction in residual cyclic rigidity was observed with the increase in depth along the shaft. Through the analysis of the mobilized loads in the bearing plates along the cycles, it was verified that the contribution to resistance from the lower bearing plate was responsible for most of the load capacity. It was also observed the influence of the interaction factors, which, by causing reloading of the pile, increased the soil rigidity and, consequently, reduced the corresponding displacements. Finally, the application of the quasi-static load cycles, in general, increased the static bearing capacity. In addition, the prediction method that approaches the value obtained in the load test was the individual bearing method.

2
  • ADNA LÚCIA RODRIGUES DE MENEZES
  • CHARACTERIZATION OF EXISTING HISTORIC MORTARS IN ILHA BELA PLANT LOCATED IN THE MUNICIPALITY OF CEARÁ MIRIM / RN

  • Leader : KLEBER CAVALCANTI CABRAL
  • MEMBRES DE LA BANQUE :
  • ERICA NATASCHE DE MEDEIROS GURGEL PINTO
  • KLEBER CAVALCANTI CABRAL
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • Data: 22 févr. 2019


  • Afficher le Résumé
  • Seeking to maintain the identity of a society, the search for conservation of cultural heritage is fundamental. The historical buildings are integral parts of this heritage, as they keep evidence of the constructive history of the building, as well as methods and materials, which is of the utmost importance to meet the principles of restoration of these assets. In this context, the objective of this work is to characterize the coating mortars of the Ilha Bela / RN. For that, an on-site visit was carried out for visual observation and photographic registration of the building, and collection of coating mortar samples for subsequent physical-chemical and mineralogical characterization through visual analysis and laboratory analytical techniques, FRX, XRD, TG / DTG, determination of binder content by acid etching, particle size distribution, water absorption by immersion and compressive strength. From the analyzes it was verified that the studied mortars are rich in lime, with agglomerant of calcitic nature and sand of silicosa origin, as aggregate, with the presence of clay. Mortars A01, A03, A04, A05 and A06 are composed of lime and sand, while mortar A02 consists of lime, sand and clay. The agglomeration / aggregate ratios are: 1: 3 for samples A01 and A04, 1: 8 for samples A02 and A03 and 1: 6 for samples A05 and A06. Thus, based on information on existing mortars, it is possible to design a compatible restoration mortar for the conservation of these historic buildings, highlighting historical and cultural values, thus contributing to the preservation of these state monuments.

3
  • JÔNATAS MACÊDO DE SOUZA
  • SOIL-CEMENT BRICKS MANUFACTURED WITH CASSAVA WASTEWATER IN SUBSTITUTION OF WATER

  • Leader : WILSON ACCHAR
  • MEMBRES DE LA BANQUE :
  • KLEBER CAVALCANTI CABRAL
  • LUCIANA DE FIGUEIREDO LOPES LUCENA
  • VAMBERTO MONTEIRO DA SILVA
  • WILSON ACCHAR
  • Data: 11 mars 2019


  • Afficher le Résumé
  • The construction industry is, admittedly one of the biggest consumers of natural
    resources on the planet. The amount of research aimed at reducing the impacts caused
    by the sector has grown considerably in recent years. The development of new

    construction materials, which contribute to the reduction of environmental impacts in
    the sector, while complying with current standards, has been debated and studied by
    researchers. One of these materials is soil-cement brick, considered an ecological brick
    and has presented enormous potential for the incorporation of waste from several
    industries, which need studies for treatment and/or reuse such as ceramic residues, rice
    husks, residues of PET bottle, etc. An environmental liability that requires research to
    be reused is cassava wastewater, an industrial byproduct (effluent), from the pressing of
    cassava in flour houses, which has a great degradation power due to its high toxicity and
    concentration of matter organic. Some authors have researched alternative solutions for
    the treatment or destination of this residue, and the production of bricks is one of them.
    Therefore, this research aimed to evaluate the physical, mechanical and microstructural
    properties of solid soil-cement bricks, produced with cassava wastewater instead of
    water. After the characterization of the materials composing as soil-cement
    formulations, 3 complete 2k experimental designs with 3 central replicates were
    designed with the aim of reducing the number of samples produced. The bands of the
    materials used were defined in 6% and 12% of cement, 0% and 100% of cassava
    wastewater replacing the water and the age of the tests at 7, 28 and 49 days. Thus, 5
    formulations were studied. The compressive strength tests were performed at 7, 28 and
    49 days. And the water absorption and modified durability tests were performed at 7
    days. In the later age, the microstructure of the bricks with 12% cement and 0% and
    100% of cassava wastewater and 9% of cement and 50% of cassava wastewater was
    studied by means of X-ray diffraction and scanning electron microscopy (SEM). The
    formulation with 12% of cement and 100% of cassava wastewater presented the best
    result in the 7 days compressive strength test, reaching 4.9 MPa. In the water absorption
    test, the same formulation also showed the best performance with the absorption of
    13.45%. In relation to the modified durability test, the composition 6% of cement and
    100% of cassava wastewater had the lowest mass loss, with 0.4%. In tests of X-ray
    diffraction, it was possible to identify the phases kaolinite, quartz, calcite, CASH
    (calcium aluminate silicate hydrate) and CSH (calcium silicate hydrate) in all samples
    analyzed. In the SEM, it was possible to verify the good densification of the samples,
    the soil particles, and typical CSH structures. It is worth mentioning that the bricks
    produced with cassava wastewater presented higher results than those obtained in the
    formulations that did not use the residue. It is possible to conclude that the results

    demonstrate the technical feasibility of the use of cassava wastewater instead of water in
    the production of soil-cement bricks, for use in masonry without structural function.

4
  • DYLSON JUNYER DE SOUZA LOPES
  • ANALYSIS OF ANALYTICAL METHODS OF RIGID TWO PILES CAPS AND THE LIMITS TENSIONS OF THE NODAL REGIONS

  • Leader : RODRIGO BARROS
  • MEMBRES DE LA BANQUE :
  • DANIEL NELSON MACIEL
  • HIDELBRANDO JOSE FARKAT DIOGENES
  • JOSE NERES DA SILVA FILHO
  • RODRIGO BARROS
  • Data: 18 mars 2019


  • Afficher le Résumé
  • The piles caps are of great importance for the balance of the structure
    and among the main difficulties encountered for the design is the fact that there is no
    consonance when dealing with the model of dimensioning and behavior of these
    elements, which leaves various gaps on the considerations that should be made in the
    dimensioning, generating discrepancies, for example, the values of the compressive
    tensions in the connecting rod and reinforcement area. This research led to an analytical
    study, compared to previous experimental tests by Delalibera (2006) and Munhoz
    (2014), using national and international design methods, with the objective of evaluate
    the limits and results that promote. Faced with this, we observe the spanish code as the
    least conservative and Santos (2013), ABNT NBR 6118 (2014) and CEB (1990) as the
    most conservative. Another important factor was the discrepancy of the values of the
    resulting of traction of the theoretical and experimental tie rods, where it presented
    variations according to the pile cap, but in all cases there was conservatism of the
    analytical methods.

5
  • CAIO CORTEZ DE LIMA
  • Identification and evaluation of urban flooding zones with the support of Geotechnologies, in Natal City, Northeast Brazil

  • Leader : VENERANDO EUSTAQUIO AMARO
  • MEMBRES DE LA BANQUE :
  • ANDRE LUIS SILVA DOS SANTOS
  • CARLOS WILMER COSTA
  • LEONLENE DE SOUSA AGUIAR
  • MARCELO SOARES TELES SANTOS
  • VENERANDO EUSTAQUIO AMARO
  • Data: 22 mars 2019


  • Afficher le Résumé
  • Urban floods motivated by heavy rains have caused significant loss of
    life and economic damage in several urban areas of the world. This flooding type have
    become frequent in many Brazilian cities. In Natal City, Rio Grande do Norte (RN)
    State Capital, Northeast Brazil, the urbanization process over the last four decades
    promoted significant soil sealing, which has reflected in numerous urban floods per
    year. This study aims to identify and evaluate areas susceptible to flooding in Natal,
    specifically in the region of Tirol, considering Digital Terrain Model (DTM), Digital
    Surface Model (DSM) of high precision, pluvial drainage system, historical records of
    flooding and hourly precipitations, in addition to reflecting the type of occupation of
    urban lots in the neighborhood. Methodological approaches were conducted and
    integrated into the Geographic Information System (GIS) environment, with the support
    of in loco high accuracy database of Global Navigation Satellite System (GNSS) for
    urban flooding analyses. The results showed that in the study area two topographic
    depressions in sectors of intense commercial and social activities stand out because they
    present geomorphological and anthropic characteristics highly favorable to flooding in
    events of Intense precipitation. Furthermore, the results allowed the generation of a
    superficial flow models with parameters of high applicability for the improvement of
    projects of urban drainage systems and urban management. This study also
    demonstrated that methodological approaches based on the use of Geotechnologies can
    subsidize risk management plans and reduce public expenditures with more effective
    works and emergency actions.

6
  • MANOEL LINDOLFO QUEIROZ NETO
  • Application of Hot Asphalt Concrete Using Waste of Construction and
    Demolition of Works (RCD) in Road in City of Natal / RN

  • Leader : ENIO FERNANDES AMORIM
  • MEMBRES DE LA BANQUE :
  • ENIO FERNANDES AMORIM
  • FAGNER ALEXANDRE NUNES DE FRANCA
  • MOACIR GUILHERMINO DA SILVA
  • WILSON CONCIANI
  • Data: 25 mars 2019


  • Afficher le Résumé
  • The construction industry is responsible for the high generation of solid waste that is
    discarded in nature, contributing to the degradation of the environment. On the other
    hand, the construction sector is one of the main components of the Brazilian economy
    and its production chain brings together a group of activities that total more than 12
    million people, about 13% representing the workforce in the country (FIESP, 2017). At
    the global level, the building materials industry is expected to grow by two and a half
    times between 2010 and 2050 (UNEP, 2002). In Brazil, the construction sector is
    expected to double in size until the year 2022 (CEBEDS, 2009). It is noteworthy that it
    is crucial to take measures aimed at the management of solid waste through cultural and
    technological changes, aiming to meet the needs of a society increasingly enlightened
    and demanding in relation to the preservation of the environment. This work presents a
    proposal for the application of construction and demolition waste (RCD) as recycled
    aggregates in the manufacture of asphalt coating, as an alternative to the use of these
    materials. The work method employed consisted of the collection of residual material in
    the company TcPav, carrying out characterization tests in accordance with the standard

    standards in the area of paving in the national scope, besides DRX, FRX and dosage by
    the Marshall method. Then an experimental section was made using a market trace,
    adapted for use with RCD. In this trait was used recycled aggregate containing gravel 1
    and sand replacing the same aggregate of the natural type in the coating layer. From the
    proposed experimental program it was observed that the residual aggregates had a good
    potential of their use in hot asphaltic coatings based on the analysis of the specimens
    under the volumetric parameters, the Marshall dosage and the experimental section. As
    for the experimental section, it was observed that in the initial months of monitoring a
    detachment of the ceramic aggregates present on its surface was observed. However,
    such detachment has not compromised to the point of damaging the coating, so that the
    asphalt pavement continues to perform satisfactorily the functionality for the vehicles
    which travel therethrough.

7
  • MARIA LUIZA ABATH ESCOREL BORGES
  • Method for the 4D BIM implementation in construction companies

  • Leader : REYMARD SAVIO SAMPAIO DE MELO
  • MEMBRES DE LA BANQUE :
  • REYMARD SAVIO SAMPAIO DE MELO
  • JOSYANNE PINTO GIESTA
  • LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • MAX LIRA VERAS DE ANDRADE
  • Data: 26 mars 2019


  • Afficher le Résumé
  • One of the problems faced in construction is the difficulty in visualizing and
    understanding the planning of the work by traditional planning tools, such as the
    Precedence Diagram Method, the Gantt Chart and the Line of Balance. This happens
    because of the generation of inaccurate and confusing interpretation schedules, due to
    the large number of activities and their precedence, as well as not providing sufficient
    context information, resulting in an abstract representation of the planning. 4D BIM-
    based modeling softwares represent a solution to this problem, since their models are a
    three-dimensional digital representation of an enterprise, associated with the activities
    durations, which allows the visualization of the execution sequence. Previous studies
    have shown that 4D BIM is, yet little discussed in the literature, while national surveys
    reveal a low BIM utilization rate for planning. In order to obtain more accurate regional
    data, BIM was characterized in the Brazilian states of Rio Grande do Norte (RN) and
    Paraíba (PB) and the results showed that local companies still do not use 4D BIM
    modeling. Adopting Design Science Research as a research method, the present work
    aimed to propose a method for the 4D implementation in construction companies,
    focused on the building process simulation using Autodesk Navisworks Manage
    software. The main contributions of this work are the mapping and systematic review of
    the literature regarding on 4D BIM papers, the scenario of the BIM utilization in RN
    and in PB, and the construction of an artifact to guide construction companies to the
    implementation of BIM 4D modeling, showing the potential of using BIM as a support
    tool for planning works.

8
  • NATHALY SANTANA LEAL DE SOUZA
  • Lightweight aggregate development from local raw materials and wastes
    (Northeast/Brazil).

  • Leader : MARCOS ALYSSANDRO SOARES DOS ANJOS
  • MEMBRES DE LA BANQUE :
  • ANA CECILIA VIEIRA DA NOBREGA
  • LUCIANA DE FIGUEIREDO LOPES LUCENA
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • Data: 28 mars 2019


  • Afficher le Résumé
  • Lightweight aggregates can be classified as natural, eg pumice and volcanic tuff, and
    artificial aggregates produced from clay, vermiculite, slag and industrial wastes. They
    are granular materials with porous structure used in several applications as thermal-
    acoustic insulation and in lightweight concretes, for example. The most traditional
    lightweight aggregate is expanded clay, manufactured in Brazil since 1968, in the State
    of São Paulo, whose production is currently concentrated in the Brazilian Southeast.
    The hypothesis that the scientific deepening in the development of lightweight
    aggregates using local waste (Rio Grande do Norte/Northeast/Brazil) may increase the

    use of lightweight aggregates, especially in lightweight structural concrete, in Brazilian
    Northeast. In this context, the study aimed to develop innovative lightweight
    aggregates, from industrial and agroindustrial wastes and regional clays
    (Northeast/Brazil), which are: the sugar cane biomass waste (SCBW), with different
    types of processing; granite and marble cutting waste (GMCW) and different clays. The
    precursors were characterized by surface area (BET), laser grain size, fineness, specific
    and unit mass, as well as thermal (DTA/TG), chemical (XRF) and mineralogical (XRD)
    analyzes. The studied mixtures had a residue content varying from 0% to 100%, and
    were submitted to sintering at temperatures of 1000°C to 1263°C in a muffle furnace.
    The aggregates produced were analyzed by the analysis of several properties: drying
    shrinkage index, visual analysis, particle density, water absorption, bulk density,
    modulus of deformation of the light aggregates, swelling index, weight loss, tensile
    strength and morphology (SEM). There were several aggregates with an particle density
    (PD) of less than 2,00g/cm³, a water absorption (WA) of less than 15% and a bulk
    density (BD) of less than 0,88g/cm³, produced with both residues, in especially those
    produced with SCBW, agroindustrial waste in contents higher than 50%, presenting PD
    of 1,39 g/cm³ and WA of 3%. On the other hand, the compositions with GMCW
    generated lightweight aggregates with PD of 1,56 g/cm³, WA of 8% and BD of 0,85
    g/cm³, in addition to having tensile strength 4 times higher than the lightweight
    aggregate marketed in Brazil. In conclusion, local industrial and agroindustrial wastes,
    associated with local clays, have the potential to produce innovative lightweight
    aggregates with excellent technical characteristics, as well as using wastes in the
    composition, making feasible a noblest destination.

9
  • EVILANE CÁSSIA DE FARIAS
  • Evaluation of durability against the combined attack of CO2 and
    Cl ̄ in self-compacting concretes with high levels of sugar cane biomass
    waste and metakaolin

  • Leader : MARCOS ALYSSANDRO SOARES DOS ANJOS
  • MEMBRES DE LA BANQUE :
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • LUCIANA DE FIGUEIREDO LOPES LUCENA
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • ANA CECILIA VIEIRA DA NOBREGA
  • GIVANILDO ALVES DE AZEREDO
  • Data: 28 mars 2019


  • Afficher le Résumé
  • The self-compacting concrete (SCC) with low comsumption of cement is an
    alternative to produce concretes that less attack the environment. The
    comercial pozzolans, such as metakaolin (MK), and the agroindustrial residues,
    for example the sugarcane biomass waste (RBC), can be used for the benefit of
    the sustainability, associated woth the possibility of maintaining, or improving,

    the rheological, mechanical and durability properties of the SCC. Among the
    mechanisms of concrete degradation, the main causers of corrosion are the
    attack by carbonation and the attack by chloride ions. Thus, the present work
    aims to analyze the performance of self-compacting concretes with high levels
    of MK and RBC submitted to the independent and combined action of
    carbonation (CO2) and chloride ions (Cl ̄). The CO2 attack occurred in an
    accelerated way through a carbonation chamber and the exposition to the
    chloride ions was done through cycles of wetting and drying. For this, SCCs
    with partial cement substitution in percentages up to 50% were analyzed, with
    five traces being performed: one with cement only, one with 30% RBC, the third
    with 20% RBC and 20% metakaolin, the fourth with 30% RBC and 10%
    metakaolin, and the latter with 30% RBC and 20% metakaolin. Subsequently,

    the SCCs properties were evaluated in the fresh state to attest the self-
    adherence criteria recommended by NBR 15823 (ABNT, 2017). In the

    hardened state, were made the tests of compressive strength, depth of
    penetration of CO2 and Cl ̄, diffusion of chloride ions by the non-stationary
    method, ultrasonic pulse velocity, electrical resistivity, corrosion potential, water
    absorption by capillarity and physicial indexes. The results showed being
    possible to produce self-compacting concretes with low comsumption of cement
    using RBC and MK and with resistances above 40MPa. The poor performance
    against carbonation of SCCs with mineral additions can be mitigated by
    increasing the coating thickness. On the other hand, when exposed to chloride,
    the concretes with additional cimentitious show better performance. The
    presence of free chloride in the samples of the SCCs causes a lower
    carbonation front. The Cl ̄ attack occurs much more severely than the
    carbonation. Finally, among the aggressive environments analyzed, the
    combined carbonation and chloride situation was the one that caused the
    greatest damage in relation to the corrosion of the reinforcement.

10
  • ANNA CHRISTINNA SECUNDO LOPES NÓBREGA
  • EVALUATION OF STRUCTURAL MASONRY BUILDINGS ON
    TRANSITION STRUCTURE BEHAVIOR CONSIDERING SOIL-STRUCTURE
    INTERACTION AND CONSTRUCTION LOADS

  • Leader : JOEL ARAUJO DO NASCIMENTO NETO
  • MEMBRES DE LA BANQUE :
  • JOEL ARAUJO DO NASCIMENTO NETO
  • JOSE NERES DA SILVA FILHO
  • LEANDRO MOUTA TRAUTWEIN
  • Data: 29 mars 2019


  • Afficher le Résumé
  • This research consisted on the evaluation of the effects caused by the construction
    sequence and the soil-structure interaction (ISE) in structural masonry buildings up
    transition structures in reinforced concrete. For this, it was used the equivalent frame
    model, developed by Nascimento et al. (2014), to simulate the interaction between the
    structural walls in the first floor of the buildings and the support structure in reinforced
    concrete, and the three-dimensional frame model, studied by Nascimento Neto (1999),
    to simulate the structural walls in the upper floors of building. The analyzes related to
    the construction sequence consisted of the gradual load and stiffness incorporation
    during the construction time; while those related to ISE incorporated the effects of the
    foundations deformability on the stresses distribution in the structure. Four modeling
    methodologies were developed for two buildings with different geometries, and the
    analyzes consisted on the evaluation of the stresses and displacements of the transition
    structure (columns and beams), as well as the stresses distribution at the base of the
    walls, for panels with different types of opening. The results show that the introduction
    of the ISE and the construction sequence do not affect the stresses routing to the
    supports, but their intensities, provoking relief or possible need for reinforcement in
    elements exceed the safety limit, dimensioned in ELU. Besides that, it was confirmed
    that the interaction with the soil reduces the differential settlements of the foundations.

11
  • MARCOS DAIAN FIGUEIREDO DA SILVA SARAIVA
  • CONSIDERATION OF THERMAL EFFECTS IN NONLINEAR
    BIDIMENSIONAL SOLIDS

  • Leader : DANIEL NELSON MACIEL
  • MEMBRES DE LA BANQUE :
  • DANIEL NELSON MACIEL
  • JOEL ARAUJO DO NASCIMENTO NETO
  • JOÃO CARLOS ARANTES COSTA JÚNIOR
  • MARCELO GRECO
  • Data: 29 mars 2019


  • Afficher le Résumé
  • This paper aims to study the thermomechanical behavior in bidimensional solids, taking
    into account the physical and geometric nonlinear effects. To consider the thermal
    effects, a formulation based on the first and second laws of thermodynamic and the
    Helmholtz free-energy is presented here. It is essential to analyze the thermoelastic and
    thermoplastic behavior in dynamic structural response. The Finite Element Method
    based on nodal positions, instead nodal displacements, is employed as geometric
    nonlinear formulation. For dynamic problems, a temporal discretization by several
    temporal integration algorithms conduces to the equation of motion solution. In
    addition, this formulation can be extended to impact problems. Therefore, the
    development of computational routines for the proposed formulation induces numerical
    results are compared with examples from the specialized literature.

12
  • LISYANNE DE VASCONCELOS FREIRE
  • MECHANICAL BEHAVIOR OF SAND AND FINES MIXTURES

  • Leader : OLAVO FRANCISCO DOS SANTOS JUNIOR
  • MEMBRES DE LA BANQUE :
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • MARIA DEL PILAR DURANTE INGUNZA
  • JOSÉ MOURA SOARES
  • RAIMUNDO LEIDIMAR BEZERRA
  • Data: 24 mai 2019


  • Afficher le Résumé
  • In the majority of engineering problems, soil is composed of different
    proportions of coarse and fine particles whose mechanical behavior is different from
    that of sand or pure clay. This study aims to determine both compressibility and strength
    of mixtures composed by sand and fines from a Post-Barreiras sediment collected in
    Natal, Rio Grande do Norte State. Sand-fines mixtures with varying fines contents of 0,
    30, 50, 75 and 100% were prepared. The mechanical characterization was performed by
    means of edometric compression and direct shear tests. It was observed that the
    compressibility parameters vary with fines content and depend on the applied stress and
    sample initial conditions. The transition fines content determined by edometric tests
    varies between 10% and 30%. It was possible to determine a single Intrinsic
    Compression Line (ICL) for the materials studied. Direct shear tests resulted in friction
    angles ranging from 30° to 38°. The addition of 30% fines increases the mixture
    strength in comparison with sand at the maximum void index. For higher fine contents,
    the maximum shear stress decreases until a value close to that observed for the fine
    matrix.

13
  • LEIDIAN ARAGÃO TORRES
  • REAL STATE PRODUCTION AND URBAN EQUIPMENTS: RELATIONS OF ATTRACTIVENESS IN NATAL/RN

  • Leader : LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • MEMBRES DE LA BANQUE :
  • LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • LUCIANA DE FIGUEIREDO LOPES LUCENA
  • TAMMS MARIA DA CONCEICAO MORAIS CAMPOS
  • Data: 31 mai 2019


  • Afficher le Résumé
  • The urban equipment are essential elements in the population's daily lives. It is through them that the city is able to provide a better life quality to its inhabitants, through access to education, health, commerce, etc. However, in Brazilian cities, the distribution of the equipments still happens in an uneven way, strengthening socioeconomic inequalities and harming a significant part of the population. Assuming that the real estate market aims to get the real estate developments closer to these equipments, in order to aggregate the externalities of the surroundings and value its products, the following research question is brought up: is there really attractiveness between the housing production and the urban equipments? This study focus on higher education institutions, hospitals and shopping centers. To accomplish that, it is pointed out the usage of spatial visualization tools such as ArcGIS®, through which it is possible to spatialize, manipulate and create distribution
    maps that aid in the analysis of the areas around the developments. The data used about the real estate developments are collected at the registries of the city. The characteristics gathered are: number of housing units, verticalization and pattern. On the other hand, the ones about the urban equipments are collected through the databases e-MEC, CNES and ABRASCE. As results, it is noticeable that educational institutions are the ones which concentrate the biggest amount of housing units in their surroundings. The hospitals are distributed in the most verticalized region and with developments presenting the highest standards among the ones analyzed - the east zone. The shopping centers are located at the spots with the biggest concentration of units. The north and west zones are the ones which present the biggest lack of equipments. Lastly, it is concluded that the study contributes in the distribution planning of new urban equipments and it is realized that the promoters concentrate the developments where there is the biggest offer.

14
  • VALBERLLAN ALBUQUERQUE RIBEIRO
  • EVALUATION OF THE INFLUENCE OF CURVATURES AND
    DIAPHRAGMS IN THE DISTRIBUTION OF THE BENDING MOMENT DUE TO
    THE LIVE LOAD IN CURVED BRIDGES OF REINFORCED CONCRETE.

  • Leader : JOSE NERES DA SILVA FILHO
  • MEMBRES DE LA BANQUE :
  • JOSE NERES DA SILVA FILHO
  • RODRIGO BARROS
  • LORENZO AUGUSTO RUSCHI E LUCHI
  • Data: 17 juin 2019


  • Afficher le Résumé
  • The structural analysis of bridges with curved longitudinal geometry presents
    greater complexity when compared to with straight bridges. This fact is due to a
    series of consequences caused by the interaction between the bending moment
    and the torsion moment. This makes torsion requests considerable, where they can
    condition the dimensioning and stability of the structure, as well as causing the
    increased distortion of the cross section of the element, generating transverse and
    longitudinal stresses that cannot be neglected. In view of this, the main objective of
    this research is to carry out a parametric study on the Influence of curvatures and
    the insertion of support transversal (diaphragms) in bridges with curved longitudinal
    trajectory in the horizontal plane, in the distribution of bending moment in the spars.
    Thus, for the analysis of the behavior of bridges, numerical models using the Finite
    Element Method (FEM) using the software CsiBridge v20 will be used, as well as
    validated by the V-Load analytical method. The analysis of the results showed that
    the inclusion of the support transversal (diaphragm) made the bending moment
    distribution more balanced for most of the analyzed models. The curvature effect
    significantly altered the distribution of the BMDF in the beams along the cross
    section of curved bridges, showing a trend of progression of these factors as it
    approaches the girder most external to the curve. Such behavior is attributed to the
    coupled effects of the bending moment and torsion moment in the curved girders.
    In addition, the curvature induces a complex state of tensions, since these
    structures are subjected to twist combined with bending and shearing. In addition,
    regarding the influence of the TI's associated to the effect of the monolithic
    systems, there is a tendency of equivalence in the load distribution of the bridges
    as the quantity of TIs is increased for both precast and in situ molded construction
    methods. Finally, with respect to the V-Load Method, although it has been used in
    the past for open-section curved bridges, results of very discrepant bending
    moment distribution are presented when compared with the MEF results.

15
  • ISABELA CAVALCANTI DE SOUZA
  • CONSTRUCTIVE PROCESS OF POST-FORMED GRIDSHELL
    STRUCTURE WITH PINUS USE

  • Leader : EDNA MOURA PINTO
  • MEMBRES DE LA BANQUE :
  • ALFREDO MANUEL PEREIRA GERALDES DIAS
  • EDNA MOURA PINTO
  • JOSE NERES DA SILVA FILHO
  • SANDRO FÁBIO CÉSAR
  • Data: 19 juin 2019


  • Afficher le Résumé
  • The gridshell structures are formed by lamellar or tubular grid-shaped
    elements, being designed and constructed in different materials, such as steel, wood and
    composites. The differential is the use of a reduced amount of material in buildings with
    large internal space, without the need for the presence of auxiliary pillars along the
    span. Thus, works of great extensions like pavilions, hangars and sheds can be executed
    in a short time. This research analyses and demonstrates the gridshells assembly
    process, details the existing construction methods and the types of connections used to
    join the pieces that form the set, giving priority to studies that highlight the use of wood
    as a raw material. A Systematic Mapping Study was also carried out with an emphasis
    on the scientific papers published in the area. This survey helped to chart the world's
    gridshell studies all over the world, identifying the countries and institutions that more
    contributed to spread articles in a 35-year window of time. The work also includes: (i)
    the listing of some existing constructive achievements; (ii) the design process and the
    projected structure modelling; (iii) the execution of small scale and full-size mock-ups;
    (iv) the theoretical and experimental evaluation of project parts; (v) the fabrication of
    the lamellar elements; (vi) the description of the construction of a grid called Dunas
    Gridshell in real scale using the pine woods (genus Pinus), showing its technical details,
    execution time and cost.

16
  • PAULO LEITE DE SOUZA JUNIOR
  • DRAINED AND UNDRAINED BEHAVIOR OF AN AEOLIAN SAND FROM NATAL/RN.

  • Leader : OLAVO FRANCISCO DOS SANTOS JUNIOR
  • MEMBRES DE LA BANQUE :
  • FRANCISCO CHAGAS DA SILVA FILHO
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • OSVALDO DE FREITAS NETO
  • Data: 21 juin 2019


  • Afficher le Résumé
  • The behavior of sands under various loading conditions has been study object in de last decades. Constitutive models able to simulate the behavior of sands have been formulated into the Critical State framework. Researchers showed that the Critical State Line (CSL) can be obtained by drained and undrained tests in samples with different initial densities. This work aims to check drained and undrained behavior of a eolic sand of Natal/RN into the Critical State Soil Mechanics. The drainded and undrained tests were carried out with samples at initial void ratio at 0,6, 0,7 and 0,8, which corresponds to dense , moderately dense and loose states, repectivelly. Tests were conducted under
    confining pressures of 50, 100, 200 and 300 kPa to each molding void ratio. The results showered that a CSL was defined from drained and undrained test in loose and moderated dense sand. The samples of dense sand were not used to define de CSL considering that critical state was not attained at a axial deformation of 20%. The Critical State parameters was obtained using the projections in p’-q and lnp’-v planes. The critical state friction angle of 31,5° is consistent with clean, angular to subangular, quartzite an uniform sands. Were obtained values of 1,26, 1,863 and 0,03 to parameters M, Γ and λ, respectively. The obtained parameters will contribute to analysis and
    numerical simulations of geotechnical structures built on aeolian deposites of dunes at Natal/RN.

17
  • LETÍCIA MARIA MACÊDO DE AZEVEDO
  • Installation of geosynthetics on flexible pavements with CBUQ: Installation
    damage.

  • Leader : FAGNER ALEXANDRE NUNES DE FRANCA
  • MEMBRES DE LA BANQUE :
  • FAGNER ALEXANDRE NUNES DE FRANCA
  • CARINA MAIA LINS COSTA
  • ENIO FERNANDES AMORIM
  • NATÁLIA DE SOUZA CORREIA
  • Data: 27 juin 2019


  • Afficher le Résumé
  • An essential means for locomotion of people and cargoes throughout
    the territory, the road transport gains an important role in the social and economic field.
    However, the low investment in infrastructure causes it to develop pathologies that need
    to be inspected, as well as the mechanisms that originated them, so the proper
    restoration or prevention alternatives can be chosen. Aiming to extend the service life of
    the pavement and to provide for users efficient trafficability conditions that meet
    comfort, economy and safety requirements, technologies have been developed and the
    use of reinforcement in road construction can be highlighted. Geosynthetics has
    increasingly been used in pavements due to reduction of time execution, costs and even
    environmental impacts. Nevertheless, if improperly handled or subjected to external
    agents, polymeric materials may exhibit unsatisfactory performance during its service
    life. Accordingly, this research was developed in an urban area of Natal, Rio Grande do
    Norte, in order to investigate the thermal and mechanical damages in geosynthetics in a
    pavement construction and compare the results obtained with the available literature
    data, since most of the studies are performed in laboratories. Therefore, samples with
    different types of geosynthetics were exposed to high temperature of the CBUQ and to
    compaction activity and then exhumed and tested by means of uniaxial tensile tests.
    Thereby, tensile strength, strain, coefficient of variation, secant tensile modulus and
    reduction factor were evaluated and compared before and after the damage. The results
    showed that subjecting geosynthetics to damages as those occurring in a pavement
    construction, in general, a decrease in tensile strength and strain is observed. Moreover,
    some reduction factors expressed higher values than those available in the literature.

18
  • EMILI CAROLINE DE ABREU ROLIM
  • REAL ESTATE PROMOTION AND YOUR RELATIONSHIP WITH THE GREEN
    AREAS IN NATAL/RN

  • Leader : LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • MEMBRES DE LA BANQUE :
  • LUCIANA DE FIGUEIREDO LOPES LUCENA
  • LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • MARIA FLORESIA PESSOA DE SOUZA E SILVA
  • Data: 28 juin 2019


  • Afficher le Résumé
  • The real estate production in urban centers causes impacts for green
    areas, which often gives space for new buildings. More and more scarce in urban space,
    the vegetation transfers to dwellings benefits that justify the interest of real estate
    developers in projects around the green areas, since the proximity to nature incorporates
    intangible values to real estate like quality of life, landscape, ventilation and fresh air.
    The present case study has as main objective to analyze the relation between the
    location of the real estate developments produced between 1990 and 2018 and the
    arrangement of the green areas in its territory. To correlate spatially these elements, the
    study will use tools of Geographic Information System (GIS) in creating maps, where
    the analyzes were made based on three criteria of the real estate production in the
    surroundings of these green areas: the intensity of the production; the standard of the
    units; and verticalization. As results it was possible to observe that: neighborhoods with
    higher average monthly income are more benefited by investments in public leisure
    areas, a situation that also favors real estate production; in general a greater pattern of
    the units located at a distance of up to 500 meters from a green area is observed, based
    on the average of private area and number of suites; and ventures located at a distance
    of up to 500 meters from a green area are more upright. Finally, it can conclude that the
    study contributed to an equitable planning and equitable planning and distribution of
    benefits of urban green spaces and thant, property developers seek to produce near these
    areas.

19
  • BRENO MARQUES FERREIRA DA SILVA
  • Probabilistic Seacliffs Stability Analysis In Rio Grande Do Norte
    State, Ne Brazil.

  • Leader : OSVALDO DE FREITAS NETO
  • MEMBRES DE LA BANQUE :
  • MAURÍCIO EHRLICH
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • OSVALDO DE FREITAS NETO
  • RICARDO NASCIMENTO FLORES SEVERO
  • Data: 26 juil. 2019


  • Afficher le Résumé
  • The coastline of the State of Rio Grande do Norte is a dynamic region. This area, which
    is composed of sandy beaches and alive cliffs of Barreiras Formation, has natural
    beauties that motivate occupation. Urbanization increases the rate of mass movements
    and sea cliff retreat. This process is an important socioeconomic issue, involving loss of
    land and risks to the population. Previous research on this topic has performed slope
    stability analysis through deterministic methods of assessment of mass movements
    risks. However, conventional slope stability analysis does not account for uncertainty in
    soil properties. In other words, the deterministic factor of safety cannot precisely
    address the state of the slope. In light of this fact, this study will perform a probabilistic
    approach through Monte Carlo simulations to assess directly the state of the cliffs of
    Barra de Tabatinga beach, in the city of Nísia Floresta/RN. Field survey, and
    computational analysis will be carried out. The probabilistic analysis will be performed
    using the software Rocscience - Slide 7.0. This research will use search methods for
    circular and non-circular slip surfaces to search effectively failure types identified in the
    area. Moreover, in order to identify the significant geotechnical parameters affecting the
    factor of safety, sensitivity analysis will be performed. This project expects to
    contribute to a better understanding of coastal retreat and represents an additional
    reliable information to the factor of safety. This methodology shall provide an
    acceptable criterion for risk assessment of the coastal cliffs.

20
  • LADDYLA THUANNY VITAL BEZERRA
  • RISK MAPPING AND STABILITY ANALYSIS OF MASS MOVEMENTS IN THE SÃO JOSÉ DO JACÓ COMMUNITY, IN NATAL/RN

  • Leader : OSVALDO DE FREITAS NETO
  • MEMBRES DE LA BANQUE :
  • OSVALDO DE FREITAS NETO
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • CARLOS WILMER COSTA
  • MARCOS BARRETO DE MEDNONÇA
  • Data: 26 juil. 2019


  • Afficher le Résumé
  • Despite being natural processes of Earth's surface dynamics, mass movements could be
    accelerated or unleashed by anthropic interference. Inadequate occupation of areas
    highly susceptible to mass movement processes, are the principal cause of accidents
    associated with landslides in brazilian urban slopes, especially those occupied by
    settlements and slums. In Natal, RN, the existence of high declivity areas allied to
    inappropriate human occupation makes the municipality susceptible to slope stability
    issues. One of the areas dealing with this problem is the São José do Jacó community,
    where this work has focused. In that context, the present research aimed to map mass
    movements occurrence risk, as well as quantify the stability of slopes neighboring the
    São José do Jacó community. A semiquantitative model proposed by Faria (2011),
    which implement the multi-criteria evaluation technique AHP in a GIS system, was
    used for risk mapping. For slope stability analysis both deterministic and probabilistic
    approaches were applied, assisted by the software Slide version 7.0, developed by
    Rocscience. The risk analysis results show a critical hazard situation for the area
    residents, mostly related to the possibility of slide mass movements, with potential
    economic, environmental, and social losses.  Considering the hypothetical condition of
    complete saturation, both deterministic and probabilistic stability analyses indicate the
    possibility of instability in sections 03 and 06. Simulations indicated stability in all
    other sections.

21
  • LARISSA CAVALCANTE DE ARAUJO MELLO
  • Effects of high temperatures on self-supported concrete with high biomass residues of sugarcane and metakaolin.

  • Leader : MARCOS ALYSSANDRO SOARES DOS ANJOS
  • MEMBRES DE LA BANQUE :
  • LUCIANA DE FIGUEIREDO LOPES LUCENA
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • WENDELL ROSSINE MEDEIROS DE SOUZA
  • Data: 29 juil. 2019


  • Afficher le Résumé
  • SCCs can reduce their high content of their contributions to become a support material for minimizing CO2 production by the cement industry. In addition, as the properties can be reduced in the mechanical properties and durability of the concrete. The performance parameter is the material of the stage in the extreme situations when it is warmed up, the ones similar to those reached in a fire. In this situation, the elasticity and modulus strength, color change and porosity, as well as effect fragmentation, can occur in concrete due to loss of water and microstructural changes. In this context, the present study aims to evaluate the high temperatures of self-compacting concretes with the contents of residues of sugarcane biomass (SCBA) and metakaolin (MK). For this, the cement was replaced by 30% by 50% by the mineral additions. No fresh state, as already existing, proved a workability of ready-made concrete. In the hardened state, as the samples were analyzed at room temperature, 200 ° C, 400 ° C, 600 ° C and 800 ° C and analyzed for tactile-visual changes, mass loss, compressive strength, ultrasonic pulse velocity, absorption of water by immersion, voids index, mass, absorption by capillarity and X-ray diffraction. CAA search results with up to 40% of their emissions are more sensitive to high temperatures and higher metakaolin insertions are left at high temperatures. Also, the mineral content content consumes the Ca (OH)2 of the medium and forms calcium silicate and aluminum hydrated.

22
  • NATALIA MEDEIROS DOS SANTOS
  • Use of wastes from the beneficiation process of granite in paving layers

  • Leader : MARIA DEL PILAR DURANTE INGUNZA
  • MEMBRES DE LA BANQUE :
  • MARIA DEL PILAR DURANTE INGUNZA
  • ENIO FERNANDES AMORIM
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • MARCONDES MENDES DE SOUZA
  • Data: 30 juil. 2019


  • Afficher le Résumé
  • The pollution generated by mining activity is one of the main issues under
    discussion in today's society. The reason for the worldwide concern is the
    consequences of the planet, prompting the adoption of effective and less
    harmful measures to the environment. In the local context, it is highlighted
    the environmental problems caused by the tailings generated during
    granite processing. The reuse used in this work comes from a deposit in
    the region of Seridó potiguar, located between the municipalities of
    Caicó/RN and São Fernando/RN. The objective of the study is the partial
    replacement of the local soil, incorporating the granite waste, in the
    proportions of 10%, 20% and 30% to the final mixtures of the paving
    layers. Tests were carried out at the UFRN and CTGÁS-ER Soils
    Laboratory to assess mineralogical, physical and mechanical properties.
    The results showed that only the sample with 10% of granite tailings
    (AM03) was efficient for the three types of paving layers (base, sub-base
    and subgrade). The analyzes of the other samples presented caveats in the
    results of the CBR or in relation to the expansion. In addition, the results
    of a simulation related to the economic feasibility of the sample that
    obtained the best performance were evaluated, based on the costs of a road
    works tendered by the Infrastructure Superintendence - INFRA / UFRN.
    The replacement of the soil in the layers of soil and base, by the material
    accounted for at zero cost, caused a reduction of less than 1% of the total
    value of the work. Although the partial replacement of the soil by the 10%
    of waste present a negligible cost reduction, it is defended its incorporation
    in the final mixture because this brings environmental benefits without
    burdening the global value of the work.

23
  • ITALO ANDRADE VASCONCELOS
  • Nonwoven geotextile used for improve the dewatering procedure of ornamental cutting rock sludge

  • Leader : FAGNER ALEXANDRE NUNES DE FRANCA
  • MEMBRES DE LA BANQUE :
  • ANDRE LUIS CALADO ARAUJO
  • FAGNER ALEXANDRE NUNES DE FRANCA
  • MARIA DEL PILAR DURANTE INGUNZA
  • Data: 30 juil. 2019


  • Afficher le Résumé
  • In the past years the production of ornamental rocks have been intensified at Brazil, especially at Espirito Santo, that it´s the major state that product that kind of rocks. Associate with the demand increase on the confection of ornamental pieces there were concerns about the amount of waste produced and its correct conduction, considering that during the process of cutting and polishing of rock, the water is used for the refrigerated the diamond disc. With that, the water used to carry the solids particles of the rock, resulting in an abrasive sludge that are generally conducted, in Brazil, to septic tank and sewage systems causing silting of the water courses due to the deposition of the solids or the sludge were deposit for decantation processes with the reuse of water. But this procedure has little effectiveness and it takes a long time to complete the desiccation because of the thinness of the solid material contained in the slurry. Due to this fact, has been known of the efficiency to use geotextiles in the desiccation of materials with small particle sizes. The present study sought to evaluate the dewatering of the sludge produced in the marble industry using three different types of geotextiles. At the beginning it was developed a prototype with small dimensions in which the geotextile was inserted in its interior. Therefore, procedure successive fillings that symbolized the fillings performed between the cutting stages at the marble industry. Observing the flow rate behavior and the reduction of the total solids content through the prototype developed, in each filler and for each geotextile under study. It observed that the geotextiles had a typical behavior in the flow outflow over time, independent of the geotextile used, besides a significant reduction in the solids content of the prototype showing the efficiency of the use of the geotextile for the drying of this type of abrasive sludge. Finally, it was concluded that the GTX300 obtained the best response in the reduction of solids content and a better distribution of the flow over time.

24
  • LANNA CELLY DA SILVA NAZÁRIO
  • Life Cycle Assesment (LCA) and Characterization of the production of

    ceramic tiles in the county of Parelhas/RN.

  • Leader : LUCIANA DE FIGUEIREDO LOPES LUCENA
  • MEMBRES DE LA BANQUE :
  • LUCIANA DE FIGUEIREDO LOPES LUCENA
  • LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • CLAUDIA COUTINHO NÓBREGA
  • Data: 31 juil. 2019


  • Afficher le Résumé
  • The red ceramics industry has great economic importance in the
    industrial sector in Rio Grande do Norte. The County of Parelhas/RN
    stands out as the main state producer, which is inserted in the biggest
    ceramic pole of the state, the Seridó. The Life Cycle Assesment (LCA)
    covers the potential environmental aspects and impacts throughout the
    life cycle of a product, considering the input and output flows of
    materials and energy. Therefore, this study aims to characterize the
    ceramics industry and perform a LCA of the production of ceramic tiles
    in the county of Parelhas/RN. In the first stage of the research the
    characterization of the local industry was carried out, through an
    exploratory research with the study of multiple cases. The second stage
    of the research had the ABNT ISO 14040:2014 and the ABNT ISO
    14044:2014 standards, that manage the LCA, as normative reference.
    The LCA was performed with a from cradle to factory gate approach,
    contemplating the steps: extraction of raw materials, transportation of
    raw material and production of ceramic tiles, comparing the
    environmental performance of the production of two ceramics. The
    characterization of industry indicates that the ceramics of the county
    have an accentuated production of ceramic tiles and use inputs extracted
    in the region of Seridó in the stages of productive process. The results of
    the LCA indicate that the production of ceramic tiles has a potential
    contribution to global warming process is the one that has the greatest
    influence.

25
  • MATTHEUS DA CUNHA PRUDÊNCIO
  • Coastal evolution of sandy beaches on the eastern coast of Rio

    Grande do Norte, Northeast Brazil

  • Leader : ADA CRISTINA SCUDELARI
  • MEMBRES DE LA BANQUE :
  • ADA CRISTINA SCUDELARI
  • CLAUDIO FREITAS NEVES
  • MICHAEL VANDESTEEN SILVA SOUTO
  • VENERANDO EUSTAQUIO AMARO
  • Data: 31 juil. 2019


  • Afficher le Résumé
  • Coastal zones are studied by several areas of science, either
    because of their socioeconomic importance in the emergence and
    development of society, or because of the environmental importance of
    these fragile transitional environments located between continental and
    marine domains. Currently, demographic growth and the occupation
    rising of these areas has been the object of higher attention worldwide
    due to the severity of the damages caused by the rapid changes resulting
    from the interaction of waves, tides and currents with the coastal
    morphology. Allied to the lack of planning in the occupation of these
    areas, there is still a great gap in the studies carried out on the processes
    and variables inserted in this environment, which exposes to danger the
    balance between the development of social and economic value activities

    and the preservation of the unique ecosystems developed in these
    regions. The study of the coastal zone is based on the observation and
    analysis of the seasonal changes of these areas that, due to their high
    environmental sensitivity, are subject to modifications that are often
    irreversible. In this context, the State of Rio Grande do Norte includes
    tourist cities equipped with dense coastal infrastructure that over the
    years presents more and more problems related to the coastal dynamics,
    especially regarding to erosion of sandy beaches. In this context, the
    present study aimed to analyze the evolution of Jacumã and Muriú
    beaches, eastern coast of Rio Grande do Norte, using the Digital
    Shoreline Analysis System (DSAS) and the Coastal Modeling System
    (SMC). The use of these tools allowed the analysis of the variation,
    amplitude and mobility of the shoreline between 1984 and 2014 and the
    characterization of the bathymetry, wave climate, currents and sediment
    transport during the 60 years (1948 - 2008). Finally, information from
    the DSAS and SMC were integrated, providing the volumetric variation
    between 1984 and 2014.The analysis allowed the identification of
    deposition episodes (mean of +0.7 m / year) from 1994 to 2004 and
    erosion episodes from 1984 to 1994 (mean of -0.9 m / year) and from
    2004 to 2014 (mean of -0.5 m / year). In addition, it was possible to
    determine the hydrodynamic characteristics (predominance of east-
    southeast direction waves and southeast direction currents), as well as
    morphological characteristics (sediment transport rate of 54,000 m³ / year
    (SMC) and 64,000 m³ / year (DSAS-SMC)). The study of Jacumã and
    Muriú beaches allowed to construct a greater understanding of the
    processes involved in the coastal evolution of these beaches. In addition,
    it allowed the visualization of the active dynamics and the identification
    of the sectors of greater sensitivity and susceptibility to changes, thus
    providing relevant information to the management and maintenance and
    preservation of the area under study

26
  • JENNEF CARLOS TAVARES
  • USE POTENTIALITY OF BANANA LEAF ASH AS PARTIAL
    REPLACEMENT OF THE PORTLAND CEMENT IN CONCRETE

  • Leader : LUCIANA DE FIGUEIREDO LOPES LUCENA
  • MEMBRES DE LA BANQUE :
  • LUCIANA DE FIGUEIREDO LOPES LUCENA
  • KLEBER CAVALCANTI CABRAL
  • ALISSON GADELHA DE MEDEIROS
  • Data: 19 août 2019


  • Afficher le Résumé
  • The use of alternative materials in the composition of concretes is
    gaining ground in the construction industry. The possibility of
    improvements in the physical, mechanical and durability properties of
    this composite, with lower associated environmental impacts, encourages
    the incorporation of mineral additions of natural origin due to the
    generation of large volumes of these wastes and a concern with their
    final destination. In this sense, the present research aims to study the use
    of banana leaf ash as partial substitution in the binder in Portland cement
    concretes. Therefore, aiming to achieve this purpose, the research
    methodology will contemplate the characterization of the materials and
    the evaluation of the properties of the concrete produced with variations
    of the contents of 0%, 5%, 10% and 15% of cement mass replacement by
    the ashes. In the ash characterization, specific mass, Blaine surface area,
    organic matter content, pozzolanic activity by modified Chapelle and
    electrical conductivity, chemical, mineralogical, thermogravimetric and
    microstructural (SEM) tests were performed. For aggregates and cement
    the physical properties tests were performed. In the next stage of the
    experimental program, the concrete was measured by the ABCP method
    and, later, the production and molding of the specimens. Regarding the

    properties of the concrete in the fresh state, it was found that the
    incorporation of the residue decreased the consistency and increased the
    specific mass, with a maximum value of 10%. Regarding the properties
    in the hardened state, the composite obtained higher compressive
    strengths with advancing ages and increasing substitution content, up to
    10%, with a decrease in values for the 15% content. Such fact, also
    observed for the specific mass. Regarding the physical indexes, the
    replacement of banana leaf ash showed lower water absorption and lower
    voids index. Thus, with the aid of scanning electron microscopy, it was
    possible to verify the presence of C-S-H, Portlandite and Etringite at all
    ages, and the presence of spherical voids, which can be characterized as
    incorporated air. Therefore, the technical feasibility of this substitution is
    favorable, considering the improvements in properties, aiming at the use
    in non-structural elements.

27
  • LUANE ASSUNÇÃO PAIVA MELO
  • COST REALLOCATION METHOD THROUGH FUNCTION
    ANALYSIS IN THE TRACK 1 OF “MY HOUSE MY LIFE”
    PROGRAM

  • Leader : REYMARD SAVIO SAMPAIO DE MELO
  • MEMBRES DE LA BANQUE :
  • DEBORA DE GOIS SANTOS
  • LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • REYMARD SAVIO SAMPAIO DE MELO
  • Data: 6 sept. 2019


  • Afficher le Résumé
  • Among all income brackets included in the mass brazilian housing
    program named “Minha Casa Minha Vida - PMCMV”, track 1 (families
    with a monthly income of up to 3 minimum wages)deficit is still the one
    with the highest housing deficit percentage, despite of the houses already
    constructed. However, this same range presents low financial
    attractiveness to construction companies, due to the Program policies. In
    addition, there is a strong demand for innovative design processes due to
    the critics existing have received: poor quality, design inadequacies and
    poor user needs. This context is a fertile field for applying Target
    Costing(TC) and Value Methodology (VM) principles. Although
    previous studies have focused on the application of TC and VM in
    PMCMV projects, the use of Function Analysis is still little explored in
    these two approaches. Therefore, this research aimed to propose a
    method for integrating Function Analysis in the cost reallocation design
    process of range 1 PMCMV projects (social housing), developing it in an
    track 1 PMCMV project conceived in a concrete wall system. Design
    Science Research was the research method. As a main result, a method
    was generated. The main contribution is to provide a way to reallocate
    costs in the design by splitting it into functions, directing the
    professionals involved to think first about the functionalities of
    compartments and spaces, later identifying design solutions, as well as
    advocates VM literature.

28
  • PEDRO MITZCUN COUTINHO
  • Comparative numerical analysis between integral and conventional

    reinforced concrete bridges subject to indirect actions of temperature,
    shrinkage and creep.

  • Leader : JOSE NERES DA SILVA FILHO
  • MEMBRES DE LA BANQUE :
  • JOSE NERES DA SILVA FILHO
  • RODRIGO BARROS
  • SERGIO HAMPSHIRE DE CARVALHO SANTOS
  • Data: 11 oct. 2019


  • Afficher le Résumé
  • This research presents a comparative study between the structural
    behavior of reinforced concrete integral bridges and a conventional
    bridge, in order to analyze the variation of efforts and displacements
    generated in the structure due to indirect actions such as creep, shrinkage
    and temperature variation. To do this, the soil deformability through soil-
    structure interaction (ISE) was considered using p-y curves where the
    neighboring soil is represented by a set of horizontal springs with
    nonlinear behavior. In addition, a three-dimensional numerical analysis
    of three-span bridges was performed using a software based on Finite
    Element Method (FEM), analyzing 03 (three) different structural
    systems: (a) integral bridge; (b) integral abutment bridge and (c)
    conventional bridge, the latter consisting of isostatic spans separated by
    expansion joints. Finally, a comparison was made between the results
    obtained with the integral bridge systems and the conventional bridge
    and a comparison of the results obtained from the FEM with analytical
    models, using NBR 6118 (2014), NBR 7187 (2003) and NBR 7187
    (1987) to check temperature action and the Eurocode 2 (2004) model for
    creep and shrinkage. The results showed that the thermal gradient action
    resulted in significant negative bending moments in the bridge end
    regions, especially in the abutment region, where the moment presented
    its maximum absolute value. Regarding the creep and shrinkage effects,
    for both types of integral systems studied, it was found that these actions
    caused unfavorable effects in the bridge end span generating the addition
    of significant bending moments, with maximum percentage variation of
    9.3%. In the abutment section, this effect was favorable, resulting in a
    reduction in the absolute value of bending moment, with a maximum
    percentage variation of 22.8%. However, although favorable, a greater
    influence of rheological effects on the ends of integral bridges was
    noticed. Finally, by analyzing the displacements in the end span of each
    model, it was possible to verify that the amplification factor of the
    deformations was always higher for the integrals bridges models,

    showing that in this structural system, the effects of creep and shrinkage
    are more significant and should be taken into account in the design.

29
  • MAELSON MENDONÇA DE SOUZA
  • DEVELOPMENT OF LIGHTWEIGHT AGGREGATES FROM
    SCHEELITE WASTE, SEWAGE SLUDGE AND RICE HUSK ASH

  • Leader : MARCOS ALYSSANDRO SOARES DOS ANJOS
  • MEMBRES DE LA BANQUE :
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • ENIO FERNANDES AMORIM
  • NORMANDO PERAZZO BARBOSA
  • Data: 30 oct. 2019


  • Afficher le Résumé
  • The use of lightweight aggregates (LWAs) is a consolidated practice in
    the construction industry. Its characteristics are relevant to various
    engineering services. However, commercial manufacture of this product
    is still quite limited. Brazil, for example, has only one LWA factory.
    Over the years, the use of expandable clays has been supporting national
    production; however, the gradual scarcity of natural resources requires
    the use of more sustainable practices. Thus, this research aims to develop
    LWAs suitable for use in engineering works and services, from the reuse
    of scheelite residue (RPS), sewage sludge (SS), and rice husk ash (RHA).
    Recent studies have shown that the production of these three wastes is

    increasing in several countries. However, in opposition to this scenario,
    the control agencies have been increasing the strictness of environmental
    laws, making various traditional methods of disposal unfeasible. Thus,
    this research can help in the preservation of natural resources and in
    reducing the environmental impacts caused by such residues. It is also
    intended to establish comparative analysis between manufactured and
    commercially available LWAs, and to evaluate the effects of sintering
    temperature and raw materials on the properties of sustainable LWAs.
    All the raw materials were benefited and later analyzed by laser
    granulometry, scanning electron microscopy (SEM), X-ray fluorescence
    (FRX), X-ray diffraction (XRD) and simultaneous thermal analysis
    (STA). Then 50 distinct mixtures were formulated from the substitution
    of clay for up to 100% of residues. The samples were dried and then
    sintered at 1100, 1150, 1200 and 1250 ° C. The manufactured aggregates
    were then characterized by analysis of swelling index (BI), mass loss
    (LOI), particle density (ρd), water absorption (WA24H), crush strength
    (S), mineralogical composition, thermogravimetric behavior and
    microstructure. Finally, the feasibility of using manufactured LWAs was
    evaluated by comparative analysis with commercial LWAs. The
    resulting aggregates showed a maximum (BI) of 77.44%, (LOI) of up to
    43.6%, (ρd) ranging from 0.63 to 2.01 g / cm³, (WA24H) of a minimum
    of 0.7%. and (S) up to 17.3 MPa. In all, 102 specimens have
    demonstrated properties at least similar to those found in commercial
    LWAs, showing the possibility of use in at least 1 major application of
    this product in engineering works and services. The results obtained in
    this experimental program reveal that it is technically feasible to use
    RPS, SS and RHA to produce lightweight aggregates with properties
    suitable for major commercial LWA applications. In addition, it was
    found that sintering temperature and raw material proportions exert a
    strong influence on the main properties of LWAs, and that the prediction
    of swelling based on the chemical composition of the mixtures proved to
    be unreliable when applied to elaborated LWAs. with RPS, SS and RHA.

30
  • RAYANDERSON SARAIVA DE SOUZA
  • MORTAR PRODUCED FROM THE SUBSTITUTION OF THE FINE AGGREGATE BY RESIDUE OF THE SCHEELITE AND THE WATER OF HYDRATION BY CASSAVA WASTEWATER

  • Leader : WILSON ACCHAR
  • MEMBRES DE LA BANQUE :
  • ANDREZA KELLY COSTA NOBREGA
  • SHEYLA KAROLINA JUSTINO MARQUES
  • VAMBERTO MONTEIRO DA SILVA
  • WILSON ACCHAR
  • Data: 29 nov. 2019


  • Afficher le Résumé
  • Mortars are homogeneous mixtures between fine aggregate, binder and water, being one of the materials most consumed by the construction industry, presenting main uses in masonry laying and coating. Aggregates account for 60 to 80% of material consumption in ready-mixed mortars, in addition to high consumption of treated water. In this sense, research has been developed to replace the constituent materials with residues that contribute to the properties of the mortars, reduce the consumption of the finite natural resources and present a destination for the residues. In this scenario the Rio Grande do Norte (RN) presents high levels of commercialization of minerals, such as tungsten that is found in the ore of scheelite. In Brazil, the main scheelite ore deposits are located in the Província Scheelitífera do Seridó. The process of beneficiation of the scheelite produces about 18,000m3 of waste/year (fine and coarse). On the other hand, the cassava processing process (Manihot esculenta Crantz) also produces some residues, such as cassava wastewater, a milky-looking liquid that flows from the roots of cassava during the pressing process to obtain starch or for the production of flour. This liquid has high content of hydrocyanic acid and high biochemical oxygen demand (BOD). Brazil is the fourth largest producer of manioc (21.08 million tons) and it is estimated the production of cassava wastewater in the proportion of 3: 1, in which for every 3 kg of manioc roots pressed, 1 liter of cassava wastewater. Both residues lack technology for their use and reduction of environmental impacts, such as visual degradation of landscape, soil, relief, air pollution and groundwater contamination. In this way, mortars for bricklaying will be analyzed with replacement of the fine aggregate by residue of scheelite (fine and coarse) and water of hydration by cassava wastewater. The residues and materials will be characterized for use in mortar in the proportion of 1: 3 (cement: aggregate) and 1: 1: 6 (cement: lime: aggregate), in volume. Afterwards, mortars will be analyzed for their freshness properties (consistency, mass density, entrained air content and water retention) and hardened (tensile strength, compression, immersion absorption, capillary absorption, bulk density and dynamic modulus of elasticity), as well as MEV analyzes to verify its technical feasibility of substitution. The expected results are the obtaining of properties, using the residues, with values within those expected for use as mortar for bricklaying.

31
  • DEIZE DAIANE PINTO GUILHERME
  • STUDY OF THERMAL AND MECHANICAL PERFORMANCE IN COATING MORTARS WITH REPLACEMENT OF NATURAL AGGREGATE BY EXPANDED VERMICULITE.

  • Leader : KLEBER CAVALCANTI CABRAL
  • MEMBRES DE LA BANQUE :
  • KLEBER CAVALCANTI CABRAL
  • LUCIANA DE FIGUEIREDO LOPES LUCENA
  • WENDELL ROSSINE MEDEIROS DE SOUZA
  • Data: 9 déc. 2019


  • Afficher le Résumé
  • The interest of the thermal performance of buildings is increasingly frequent due to user requirements and improvements in the supervision of the performance standard NBR 15575 (ANBT, 2013), which establishes the minimum efficiency criteria of a building. We highlight the charges related to thermal behavior, because they impact on the construction, the environment and affect the comfort and costs of users. An alternative to solve this problem is to change the constituent materials of the building systems, such as the use of lightweight aggregates with thermal insulation potential. In this context, the objective of the present work is to analyze the thermal and mechanical performance of natural mortar with expanded vermiculite. The experimental procedure began with the characterization of the materials and the production of the mortars with the trace volume 1: 1: 6 (cement: lime: sand) with replacements of 25, 30, 35, 40, 45 and 50% of the sand by vermiculite. , and then fresh tests (consistency, density and water retention), hardened tests (density, tensile and compressive strength, modulus of elasticity, capillary and immersion absorption and adhesion resistance) and finally thermal testing with the KD-2Pro appliance and thermal performance through a prototype simulating the incidence of heat on a wall. The results show that the workability was improved according to the incorporation of expanded vermiculite, the density in the fresh and hardened state was reduced, the compressive strength decreased slightly, the voids index and the bond strength increased. All sealing systems with ceramic bricks coated by the mortars under analysis met the requirements established by NBR 15575 (ANBT, 2013). The thermal performance evaluated by the prototype showed an improvement in thermal insulation according to the incorporation of expanded vermiculite, obtaining more significant results for mortars with 45 and 50% substitution, which came to isolate 34 ° C and 40 ° C, respectively. Therefore, the expansion of expanded vermiculite in cement mortars is able to benefit from thermal insulation without causing major damage to other mortar properties, making it a product with good thermal and mechanical performance.

2018
Thèses
1
  • LUIZ AUGUSTO DA SILVA FLORÊNCIO
  • GEOTECHNICAL RELIABILITY ANALYSIS OF A CANTILEVER PILE WALLS IN SAND

  • Leader : CARINA MAIA LINS COSTA
  • MEMBRES DE LA BANQUE :
  • CARINA MAIA LINS COSTA
  • YURI DANIEL JATOBA COSTA
  • JEFFERSON LINS DA SILVA
  • Data: 26 févr. 2018


  • Afficher le Résumé
  • Geotechnical structures are subject to different uncertainties. These uncertainties are due to the natural variability of the soil properties, as well as because the limited knowledge of the several related events. The evaluation of these uncertainties is possible by the application of the reliability theory. Despite its adoption in international standards and the large number of scientific researches, the application of probabilistic theory in Brazil is still unusual, mainly in retaining structures. Accordingly, this work presents the development and application of calculation routines to analyze the geotechnical reliability of a cantilever pile wall. The first group of routines evaluates the reliability of the ultimate limit state (ULS) through FORM (First Order Reability Method) and Monte Carlo simulation. The second group of routines evaluates the reliability of the Service Limit State (SLS) using Monte Carlo simulation. The routines were developed using the Python language. Particularly for SLS evaluation, the Plaxis 2D finite element software was used to obtain the horizontal displacement values. A cantilever pile wall typically constructed in Natal/RN was used to apply the routines and to conduct the parametric study. It was verified that the most influential variable for the cantilever wall was the soil friction angle. The change in the coefficient of variation of the soil friction angle did not change the final reliability of the pile wall, because the embeddedment depth was oversized. Keeping the depth of excavation constant, the increase of the embedment depth has rapidly dropped to the failure probability and the design points of the FORM. For SLS, the increase in maximum horizontal displacement decreased the failure probability and increased the reliability index in a linear trend. The use of lognormal distribution reduces the failure probability in both ULS and SLS.

2
  • ILANA MARIA DA SILVA BARROS
  • THERMAL AND MECHANICAL ANALISYS OF COATING MORTARS WITH ADDITION OF EXPANDED VERMICULITE INSTEAD OF AGGREGATE 

  • Leader : KLEBER CAVALCANTI CABRAL
  • MEMBRES DE LA BANQUE :
  • KLEBER CAVALCANTI CABRAL
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • ANDREZA KELLY COSTA NOBREGA
  • WENDELL ROSSINE MEDEIROS DE SOUZA
  • Data: 9 mars 2018


  • Afficher le Résumé
  • The search for building materials that lead to advances, especially as regards to the aspect of energy efficiency of buildings, is increasingly constant nowadays. In Brazil, the Performance Standard (ABNT NBR 15575: 2013) establishes the minimum standards about the efficiency of buildings in the country, bringing among criteria of structural stability and useful life, the guidelines to obtain thermal and acoustic comfort, and fire safety. In this context, there is a growing number of studies aiming to investigate the use of lightweight aggregates, such as expanded vermiculite, which has important properties, specifically low thermal conductivity and high fire resistance. Thus, the current research sought to evaluate the thermal performance of mortars in the 1: 1: 6 volume, with the addition of expanded vermiculite (superfine) in defined percentages of replacement to the small aggregate (25%, 50%, 75%, and 100%). The experimental procedure was initiated with the chemical, mineralogical, microstructural and thermal characterization of the expanded vermiculite, and with its physical characterization and with the constituent sand. The analysis of the properties of workability, water retention, retraction, capillary absorption, and mechanical strength of each mixture was performed. In order to determine the energy efficiency of the coating, thermal characterization tests of the mortar were carried out using the KD-2 Pro and a prototype. In the results of the fresh and hardened state, it was observed that the mortars containing expanded vermiculite presented higher water consumption, lower mass density, higher water retention capacity, reduction of mechanical strength and modulus of elasticity, and increased capillary absorption and index of voids. In the analysis of the thermal performance, it was observed that, in ceramic brick sealing systems, whatever the mortars used and the bioclimatic zone chosen, all meet the thermal transmittance requirements required by NBR 15575: 2013, and only the mortar with 100% of vermiculite does not meet the established limit of thermal capacity. In the concrete block fence system, only 75% and 100% replacement mortars contribute with all the thermal transmittance requirements required for the system. However for the thermal capacity limits, all are considered adequate. The good thermal performance was also confirmed in the experiment with the prototype, when the heat reduction propagation from one environment to the other with the addition of vermiculite in the mixture. Thus, it is indicated that the addition of expanded vermiculite in mortars results in coatings with good thermal performance, which can meet, according to the situation, the requirements established by the ABNT NBR 15575:2013.

3
  • PLÁCIDO GONDIM DE SENA NETO
  • ANALYSIS OF DOSINGS OF ASPHALT CONCRETE OF THE PRE-MIXED COLD (PMF) TYPE USING WASTE FROM CONSTRUCTION AND DEMOLITION OF WORKS (RCD)

  • Leader : ENIO FERNANDES AMORIM
  • MEMBRES DE LA BANQUE :
  • ENIO FERNANDES AMORIM
  • FAGNER ALEXANDRE NUNES DE FRANCA
  • MARIA DEL PILAR DURANTE INGUNZA
  • VALTENCIR LUCIO DE LIMA GOMES
  • Data: 16 mars 2018


  • Afficher le Résumé
  • Considering the great growth of the civil construction sector in Brazil until 2013/2014, some companies, and the economy in general, were highlighted by the high rate of urban development. Such events were directly responsible for the market development that stimulated various sectors of the economy, one of which is the construction sector. With these events, as a consequence, some negative aspects occur in a damaging and irreparable way. For example, researchers say that concrete using Portland cement today is the second most-consumed product in the world, with a prospect of increasing its consumption over the next few years. Based on these aspects, this work will address points related to the reuse of Waste from Construction and Demolition of Works (RCD), which guides the theme of this work, stressing the importance and benefits of some sustainable actions for the environment and society. In a regional context, in the state of Rio Grande do Norte there are 04 RCD recycling plants, responsible for collecting, processing and marketing all the material coming from construction debris. These companies generate income for the local population and contribute to the reduction of mineral extraction (raw material exhaustible). In view of these facts, the present study aims to evaluate the technical feasibility of waste from civil construction, using them as aggregates, after beneficiation in the plant, in the composition of asphalt concrete replacing partially or totally natural materials. The employed method is based on the collection of material in the field and on the characterization tests and dosages of pre-mixed in cold, in accordance with the standardized standards in the area of paving in the national scope. Regarding the analysis of the obtained results, the expressive potential of its use in the composition of cold asphaltic concretes is inferred qualitatively.

4
  • VICTOR VINICIUS DE OLIVEIRA FERREIRA
  • CAATINGA SPECIES INDICATED FOR CIVIL CONSTRUCTION

  • Leader : EDNA MOURA PINTO
  • MEMBRES DE LA BANQUE :
  • EDNA MOURA PINTO
  • JOSE NERES DA SILVA FILHO
  • ROSIMEIRE CAVALCANTE DOS SANTOS
  • Data: 21 mars 2018


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  • Wood is a sustainable material with multiple purposes, with civil construction among them. Much of the wood consumed in Brazil comes from the Amazon Forest, and although the country has great forest potential, a culture of masonry construction is predominant. The Caatinga is a rich and special biome with great exploitation potential for civil construction. Caatinga tree species have characteristics of short height and tortuous stems with small diameters. The main destination of these species is for use as firewood and coal. Thus, the present study aims to analyze the feasibility of using Caatinga wood species in the composition of constructive systems and structural elements. Caatinga species with potential use in construction have been identified, and the species Angico, Jurema Preta, Mororó and Pereiro were selected. Samples were collected from 48 trees, corresponding to twelve of each species from the Riacho do Cabra Farm located in the Municipality of Santa Cruz-RN. Wood splitting was carried out at the Escola Agrícola de Jundiaí (EAJ) in the Municipality of Macaíba-RN and characterization tests were carried out at the University of São Paulo (USP) in São Carlos-SP. The characterization corresponded to assays for density, dimensional stability, compressive strength, traction parallel to the fibers and shear strength according to the NBR 7190:1997. The data were analyzed in accordance with the Standard NBR 7190:1997 by calculating the characteristic resistances, the mean values and the standard deviation of the variables. The Spearman Correlation test was used and the level of significance was set at 5%. The density test result evidenced denser woods with values close to wood commonly used in construction such as Maçaranduba and Jatobá. The species presented good values for compressive strength parallel to the fibers and the shear strength, both being classified as average. The other mechanical and stiffness properties were classified as weak. Angico stood out with the highest values of compressive strength, traction parallel to the fibers and stiffness. Jurema Preta had the highest shear strength value. A statistical significance was found between the apparent density and the compressive strength parallel to the fibers in Angico (p = 0.002) and Mororó (p= 0.006); compressive strength parallel to the fibers and modulus of elasticity for compression parallel to the fibers in Angico (p=0.055) and Pereiro (p=0.022); modulus of elasticity for traction parallel to the fibers and tensile strength parallel to the fibers in Jurema Preta (p=0.040); and highlighting the Angico species with a strong strength correlation of apparent density and compressive strength parallel to the fibers. Thus, the physical properties, the strength and stiffness values were representative for all species, evidencing their possible use in civil construction as fences, braces, scaffolds, roofing elements, frames in general, beams, wainscoting/paneling, panels, mountings/trimmings, linings, and skirting boards/footers, as well as in construction systems such as the lamellar structural system.

5
  • NAYARA JHÉSSICA MARQUES DA FONSÊCA
  • POTENTIAL OF CEMENT SUBSTITUTION BY LIME IN SOIL-CEMENT BRICKS WITH INCORPORATION OF CERAMIC WASTE


  • Leader : WILSON ACCHAR
  • MEMBRES DE LA BANQUE :
  • WILSON ACCHAR
  • JAQUELIGIA BRITO DA SILVA
  • ANDREZA KELLY COSTA NOBREGA
  • VAMBERTO MONTEIRO DA SILVA
  • Data: 26 mars 2018


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  • The construction industry is an important industry in the economic system in which it operates. In addition to generating employment and income for the population, the sector also contributes to improving the environment, safety and well-being. However, high resource ratios are used for construction as well as large waste management systems generated by it, the major concern regarding the negative environmental impact generated and the serious consequences. In view of the high-energy consumption in the cement manufacturing process, large amounts of CO2 emitted during the clinker burning, the availability of slaked lime and the high rate of loss involving ceramic blocks used in masonry seal, this work aims to evaluate the potential of cement substitution by lime in soil-cement bricks with ceramic waste incorporation. It will be performed ternary compositions of soil + 12% cement + 4% residue ceramic, soil + 12% hydrated lime + 4% residue ceramic, quaternary soil + 6% cement + 6% hydrated lime + 4% residue ceramic. Developing all compositions without addition of ceramic waste to serve as reference and enable the analysis of the influence of the residue on the behavior of the produced bricks. After the processes of pressing and curing of the bricks, they are submitted to the tests of resistance to simple compression, water absorption and modified durability. Then, scanning electron microscopy and test X-ray diffraction will analyze the fracture surfaces of these materials. It is expected that, given the silica and alumina contents present, both in the used soil and in the finely ground ceramic waste, the so-called pozzolanic reaction occurs. In this reaction, the calcium hydroxide resulting from the hydration of the cement and / or lime reacts with the aforementioned silica and alumina forming hydrated silicates and calcium aluminates that may contribute to the improvement of the physical and mechanical properties of the compositions studied. In this context, it is expected that the produced bricks present good conditions of strength and durability in accordance with the recommendations of the current Standards for bricks in non-structural application. The first experimental results showed that, in terms of resistance to simple compression, water absorption and modified durability, the ternary composition soil + 12% cement + 4% ceramic residue presented more significant values. In the quaternary mixtures, the formulation soil + 6% cement + 6% lime and 4% ceramic residue showed performance better.

6
  • DANILO PONTES PESSOA E SOUZA
  • REAL ESTATE INCORPORATIONS’ PRODUCTION IN NATAL/RN
    BETWEEN 2000 AND 2015: Impacts in the local market through the
    performance of external and local companies.

  • Leader : LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • MEMBRES DE LA BANQUE :
  • LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • JOSYANNE PINTO GIESTA
  • JOZILENE DE SOUZA
  • TAMMS MARIA DA CONCEICAO MORAIS CAMPOS
  • Data: 26 mars 2018


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  • The real estate market represents a large share of the construction
    industry, accounting for a significant percentage of Brazilian economy’s GDP. In
    the last few years, this sector has been experiencing an increasing influence of
    the financial market, represented by the opening of capital of great companies of
    the branch, as well as by the expansion of the housing credit by public and private
    financial institutions. These facts contributed to the expansion of the real estate
    production to others Brazilian cities, affecting, significantly the local markets. In
    the specific case of Natal (RN), the entrance of external companies had a strong
    impact on the quantity, typology and location of the housing units produced,
    especially between 2008 and 2011. After four years of intense real estate
    production, it is remarkable the decline in the number of projects launched and
    even the closure of the activities of some companies in the local market. The
    large number of housing units offered apparently led to a rapid saturation of the
    consumer market, which, combined with the advent of the economic crisis and
    mainly the contraction of credit, resulted in a drastic reduction in launches. Thus,
    the present research sought to understand how real estate production in the local
    market occurred between 2000 and 2015, by comparing the production of
    external companies with the locals companies. By analyzing and interpreting
    quantitative data obtained from real estate registries, we sought to deepen our
    understanding of the process, and it was concluded that, despite the apparent
    disparity, the real estate production of the external companies studied was
    quantitatively smaller, but with standards and spatialization similar to the local
    companies.

7
  • RAY DE ARAUJO SOUSA
  • NÃO CONSTA

  • Leader : OLAVO FRANCISCO DOS SANTOS JUNIOR
  • MEMBRES DE LA BANQUE :
  • FAGNER ALEXANDRE NUNES DE FRANCA
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • OSVALDO DE FREITAS NETO
  • RICARDO NASCIMENTO FLORES SEVERO
  • Data: 26 mars 2018


  • Afficher le Résumé
  • NÃO CONSTA

8
  • ANDREZZA VAGNIELLY COUTINHO GERMANO
  • Making-do waste prevention method in construction sites.

  • Leader : REYMARD SAVIO SAMPAIO DE MELO
  • MEMBRES DE LA BANQUE :
  • REYMARD SAVIO SAMPAIO DE MELO
  • LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • DEBORA DE GOIS SANTOS
  • Data: 28 mars 2018


  • Afficher le Résumé
  •  

    Lean construction is a production philosophy that seeks to reduce or eliminate wastes in
    construction processes. Making-do is a category of waste related to the occurrence of
    improvisations by the work teams. Rework consists of a new execution of a task that
    has already been executed. Unfinished work refers to the non-completion of the tasks.
    The study of wastes in construction is of fundamental importance in improving the
    performance of construction processes as well as in cost reduction. There are important
    cause and effect relationships between the categories of making-do, rework, and
    unfinished work that are often related to failures in management systems that have not
    prevented the spread of wastes. Thus, the main objective is to propose a method of
    preventing wastes of the type making-do, rework and unfinished work in construction
    sites. To do so, the research approach is called Design Science Research composed of
    five phases: (1) "Problem awareness" in which the knowledge gap was obtained; (2)
    "Suggestion" of the prevention method; (3) "Development" of the second version of the
    method, where the refinement of the first version of the method occurred. (4)
    "Evaluation" consisted in evaluating the practical utility of the second version of the
    artifact through the focus group with professionals from one of the three companies
    studied, in this sense some of these assessments were incorporated in the last version of
    the method; (5) "Conclusion" in this last phase was identified the practical and
    theoretical contributions. The results obtained in case study 1 and 2 indicated that most
    of the wastes by making-do were materials / components and the impacts are rework,
    unfinished work and decrease of productivity. In the case study 3, the informal packages
    caused by unfinished work are mostly masonry of sealing and internal coating and were
    the most increase of deadlines and costs had. The main contributions of this study are
    related to the understanding of the wastes from a systemic perspective from its origin to
    the impacts on the production system, as well as to make the management systems more
    robust and to seek the reduction or elimination of wastes in a more effective way.

9
  • RAYMISON RODRIGUES CARDOSO
  • STRUCTURED LAND WITH JET GROUTING AND REINFORCED ENGINES WITH GEOSYNTHETICS BUILT ON SOLO MOLE: CASE OF BRIDGE ENCOUNTER ON THE CURIMATAÚ RIVER, BR-101 / RN.

  • Leader : FAGNER ALEXANDRE NUNES DE FRANCA
  • MEMBRES DE LA BANQUE :
  • FAGNER ALEXANDRE NUNES DE FRANCA
  • ENIO FERNANDES AMORIM
  • MOACIR GUILHERMINO DA SILVA
  • ALEXANDRE DA COSTA PEREIRA
  • Data: 28 mars 2018


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  • A structure foundation, whether a highway or a building, requires geotechnical conditions of stable soils, meaning that the planned investment is without risk. In case if that is non-existent, the geotechnical engineer should to do a needed analysis,  in order to solve possible risks. The presence of soft soil in any terrain, whether from surface or even in sub horizontal layers, naturally makes necessary a stability calculation, usually it involves computational analysis. This study contributes to a better knowledge of the landfill technique over reinforced soft soils with jet grout column, preceded for load transfer platform with geosynthetic, so as his evolutionary behavior in consolidation process resulting time. The study case place is detailed and the made geotechnical investigation will be present. As the used parameters are presented in landfill construction project over soft soil of the work project of duplication of BR-101/RN highway, the called northeast corridor, his history and geotechnical baseline. The methodology adopted shall be demonstrated to made road structural reinforcement with jet grouting technique, being described how the estimated parameters are used in modeling treated soil. The application of the proposed methodology is presented using as geotechnical scenario the soil characteristics of the Vale do Curimataú area with this model utilization, it is intended to compare numerically the displacement datas that was measured in field, this area has a failure before this intervention study. Were observed a failure conditions  and excessive deformations and to stabilize it, was applied the jet grouting technique. The building behavior  was analyzed in pre-construction period. To a successful performance of landfill over soft soil, it makes necessary to monitor in all the construction stages, installing control instruments to follow the soft layer and massif performance, movement soil evolution, the horizontal displacements, and prevent of some future problems that could negatively affect the landfill stability.

10
  • HUGO ALESSANDRO ALMEIDA DINIZ
  • STUDY OF DURABILITY INDICATIVES AND MECHANICAL PROPERTIES OF SELF COMPACTING CONCRETES WITH HIGH LEVELS OF MINERAL ADMIXTURES.

  • Leader : MARCOS ALYSSANDRO SOARES DOS ANJOS
  • MEMBRES DE LA BANQUE :
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • GIVANILDO ALVES DE AZEREDO
  • Data: 5 avr. 2018


  • Afficher le Résumé
  • Self-compacting concrete (SCC) is an innovative product that has fluidity and cohesion to traverse the entire length of the part and fill the spaces between armatures, optimizing the execution of concrete and reducing costs with labor. For this it is necessary to increase the content of fines, and consequently of cement, the main pollutant compound of the concrete. The use of mineral admixtures rich in amorphous silica and aluminum such as Metacaulim, pozzolan rice husk and sugarcane biomass are an alternative to the reduction of cement, since they confer benefits to the cement matrix and are industrial waste. However, the admixtures cause the reduction of Calcium Hydroxide, the protective barrier of concrete against carbonation. In this attack there is reduction of alkalinity and formation of carbonate products that alter the porous structure of the matrix and make the environment aggressive to the reinforcements. As the pore network is responsible for the entry of CO2, the present project intends to investigate the influence of porosity and realcalinization with hydrated lime on self-compacting concretes, with low cement content and high levels of mineral additions from industrial and agroindustrial residues, submitted to carbonation processes. It is expected to correlate the fluid transport properties within the SCC with the carbonation process, evaluating the action of the realcalinization through the hydrated lime in the fight against CO2 penetration, due to the pozzolanic reactions and the high cement substitution content; And, the alteration of the behavior of the SCC with different residue rates of sugarcane biomass.

11
  • EDUARDO DE CASTRO BITTENCOURT
  • BEHAVIOR OF PILED RAFT ON SANDY SOILS

  • Leader : OSVALDO DE FREITAS NETO
  • MEMBRES DE LA BANQUE :
  • OSVALDO DE FREITAS NETO
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • RENATO CUNHA
  • Data: 6 avr. 2018


  • Afficher le Résumé
  • It is observed in the last decades, the search of the optimization
    of pile foundations from the analysis of the benefit that the contact of the pile
    cap or raft with the ground can confer to increase the load capacity and the
    increase of the stiffness. Contribution that is not inserted in the design of the
    foundation system by the traditional methodology of pile group. Thus, in the
    present dissertation an analysis of the behavior of a foundation conceived by
    the pile group methodology was carried out, in light of the piled raft, through
    numerical modeling. The study work is from Instituto Cérebro, located in the

    Central Campus of the Federal University of Rio Grande do Norte (UFRN),
    Natal-RN. Theoretical and experimental studies, highlighting pioneering and
    more recent searchs on the theme of this work, were used as subsidies to
    present the state of the art of foundations in piled raft. The study foundation
    consists of bored piles of the continuous flight auger, composed of lengths of
    15, 17 and 20 m and diameters of 250, 400 and 500 mm. For the analysis of the
    behavior of this foundation, the numerical program PLAXIS 3D Foundation,
    based on the Finite Element Method (FEM), developed by Delft University (Delft
    University of technology) was used. To verify if the program was handled
    correctly, the verification of the software was done through comparative
    analysis of cases previously studied by other researchers. The program input
    data and back-analysis of soil geotechnical parameters were subsidized by
    Standard Penetration Test (SPT), carried out in the field according to the
    procedures recommended by NBR 6484/2001 and static load tests (PCE),
    carried out according in NBR 12131/2006. The local subsoil, which was
    modeled assuming its elastic behavior perfectly plastic, is formed by layers of
    fine and medium sand, little compact silt, until reaching the impenetrable. The
    water level was not detected in any of the 13 boring performed. It was observed
    in the results obtained that the interaction of the pile cap with the soil increased
    the load capacity and stiffness of the system. The pile cap presented up to 21%
    contribution in receiving the efforts applied in the foundation. In addition, it has
    been observed that the load capacity of the piled raft foundation system is not
    confined to the algebraic sum of the isolated resistances of the pile cap and
    pile(s). Considering these results, it can be concluded that the methodology of
    foundation in piled raft is configured as a positive foundation technique for the
    city of Natal for medium-sized buildings.

12
  • PEDRO HENRIQUE PINTO CAMPOS
  • EVALUATION OF SPACE INTERPOLATION METHODS AND REMOTE SENSING TECHNIQUES IN THE BATHYMETRIC CHARACTERIZATION OF THE POTIGUAS BASIN

  • Leader : VENERANDO EUSTAQUIO AMARO
  • MEMBRES DE LA BANQUE :
  • VENERANDO EUSTAQUIO AMARO
  • MARIA DE FATIMA ALVES DE MATOS
  • MICHAEL VANDESTEEN SILVA SOUTO
  • Data: 20 avr. 2018


  • Afficher le Résumé
  • The extraction of bathymetry by satellite image is an activity that has been evolving in its methodology due to the aerospacial technological advances. Satellite images of a wide electromagnetic capture are able to bring information that are beyond traditional photographs. They are images that, through some specific calculations methodologies can show, for example, the depth of the ocean. The literature shows that it is not yet known which calculation methodology is most appropriate. Another key point involved in the process is the generation of bathymetric maps by interpolation from clouds of points, there are several methods of interpolation today, but much is still debated about which are the most appropriate for each case. The mapping of the seabed is an activity performed for several purposes. It can be used for navigation, oil reservoir prospecting, environmental monitoring, wave modeling, coastal erosion study and others. Brazil has one of the largest coastlines in the world with more than 8500 km of extension, many of its cities have been installed on the coast and are submitted to the consequences of problems associated with the sea, such as undertow, coastal erosion, urban disorder, landscape impact, ecological impact etc. This necessitates a deeper study of ocean floor mapping models. Moura (2010) did the interpolation analysis using bathymetry data obtained by Nautical Charts and bathymetry data obtained in loco. In his work a series of 12 interpolators were evaluated. A satellite image of Gomes et al. (2007) was used to aid in a visual evaluation of the results. The present work has as general objective to complement the analysis of Moura (2010), providing a quantitative reference to make this evaluation, from a bathymetry extraction of a Landsat 8 Satellite Image of the region. The methods of bathymetry extraction used were Mcfeeters (1996) and Philpot (1989). The extraction of bathymetry was done with the software Arcgis, Envi and Matlab. The interpolations were made in the Surfer and the data were compared to each other using the statistical analysis of Correlation Coefficient (R²), concordance index (d), MAPE, RMSE and Cross Validation. In terms of the results of the bathymetry extraction, Mcfeeters (1996) was the method that brought better representation of the region. In terms of result of the interpolations of the in-situ bathymetry data, the Interpolators Local Polynomial, Inverse Distance, Minimum Curvature were chosen the most representative methods. For nautical chart data, the Natural Neighbor, TIN, Kriging, and Radial Base Function interpolators were classified as the most appropriated interpolation methods because they had the best statistic results.

13
  • MARIANA SILVA FREITAS
  • ANALYSIS OF THE DISPLACEMENTS AND BENDING MOMENT IN THE
    FOUNDATIONS AND IN THE COLUMN OF A BRIDGE IN REINFORCED
    CONCRETE CONSIDERING THE SOIL-STRUCTURE INTERACTION (ISE)

  • Leader : JOSE NERES DA SILVA FILHO
  • MEMBRES DE LA BANQUE :
  • JOSE NERES DA SILVA FILHO
  • DANIEL NELSON MACIEL
  • RODRIGO BARROS
  • RICARDO JOSÉ CARVALHO SILVA
  • Data: 4 mai 2018


  • Afficher le Résumé
  • The research presents an analytical and numerical study considering the
    soil-structure interaction (ISE) of the displacements and bending moment in the
    foundations and in the column of a bridge in reinforced concrete. For do this, some
    classic analytical models of soil-structure interaction (ISE) were studied focusing
    on the Matlock and Reese solution and on the Elastic Differential Equation solution
    obtained using the Fourier series. The results of horizontal displacements and
    bending moment were compared with those obtained by numerical modeling
    performed by the softwares SAP 2000 and CSi Bridge V17. The obtained values
    corroborated that the computational methods, when calibrated by reliable input
    parameters, tend to distance themselves less from the physical reality of the
    phenomenon than the analytical methods, since they allow simulating the problem
    in a more realistic way. Finally, it is emphasized that the quality of the response
    that is obtained using computational models must be taken with caution by the
    designers, always considering the sensitivity of the models adopted.

14
  • YEZA CÂMARA SANTIAGO DE MEDEIROS
  • NON-DESTRUCTIVE EVALUATION OF STRUCTURAL CONCRETE BLOCKS

  • Leader : JOEL ARAUJO DO NASCIMENTO NETO
  • MEMBRES DE LA BANQUE :
  • JOEL ARAUJO DO NASCIMENTO NETO
  • RODRIGO BARROS
  • ANDREA BRASILIANO SILVA
  • HIDELBRANDO JOSE FARKAT DIOGENES
  • Data: 30 mai 2018


  • Afficher le Résumé
  • The systematic work of the structural masonry construction system in the brazilian civil construction market currently demands technical solutions that aim to evaluate the quality of its components in a quick, economic and effective way. Although the compressive strength of masonry walls is represented by the joint action of its components (block, laying mortar and graute), blocks are responsible for the largest share of this resistance. To ensure the quality of the blocks, NBR 6136 establishes requirements. Among them, the blocks must have sharp edges and must not show cracks, fractures or other defects. The most common way to identify such defects is by performing a visual inspection, a time consuming process in the middle of a production line. In this context, the article presented an alternative for the identification of failures in concrete blocks by means of non-destructive tests. After analyzing the spectra of the blocks obtained experimentally by the impulse excitation technique - using microphone and accelerometer - and theoretically by the numerical modal analysis, it was possible to perceive patterns in the acoustic response of the intact blocks of the M-15 and M-20 family (brazilian blocks sizes). Thus, it was established criteria for the quality control of the blocks by using resonant ultrasound spectroscopy. The main objective of this study was to try non-destructive testing methodologies in order to evaluate the conformity of concrete blocks for structural purposes, where a standard spectrum has been established and its efficacy assessed on hollow components.

15
  • KAIQUE YURI MARCIO ARAUJO
  • ANALYSIS OF REINFORCED CONCRETE PILE CAP STRUCTURAL
    BEHAVIOR AS ONSHORE WIND TURBINE FOUNDATION

  • Leader : RODRIGO BARROS
  • MEMBRES DE LA BANQUE :
  • JOEL ARAUJO DO NASCIMENTO NETO
  • JOSE NERES DA SILVA FILHO
  • LEONARDO MELO BEZERRA
  • RODRIGO BARROS
  • Data: 18 juin 2018


  • Afficher le Résumé
  • The growth of the wind energy industry in Brazil has demanded projects of big
    size foundations, which in most cases are pile caps. These structural elements
    spend close to 300 cubic meters of concrete and 20 tons of steel in its
    construction. In this context, a deepest structural analysis about this kind of
    wind turbine foundations should contribute to improvement of projects in this
    sector, that are of great relevance for the development of the Brazilian energy
    matrix. In that way, this work proposes to analyze the structural behavior of
    reinforced concrete pile caps, as onshore wind turbine foundations, using
    numerical models. In order to do, eight finite elements models were
    constructed, with the aid of the ANSYS V17 and SAP2000 V17 softwares. It

    was adopted as variables: the finite element type used for modeling the pile cap
    and piles (solid or shell); the soil representation (spring or semi-infinite space);
    and, the consideration or not of the soil under the pile cap base. All the
    materials constitutive models were considered as with linear elastic behavior.
    The interest results were: pile´s reaction; division of loading between soil and
    piles; pile cap´s deformation; radial normal stress and bending moments in the
    pile cap; and, the increase of vertical stresses in the soil. The models designed
    in solid elements and plate elements demonstrated good compatibility between
    the found values. In some models, the numerical analysis showed results
    against the structural safety of the foundation when the soil under the pile cap is
    not considered. In addition, an equivalence was found between the soil elastic
    properties, such as Young´s modulus (Esoil) and modulus of subgrade reaction
    (k s ), in the numerical models analyzed.

16
  • RENNAN AUGUSTO SILVA CAVALCANTI
  • PRELIMINARY STUDY TO ANALYSIS OF PROGRESSIVE COLLAPSE IN STRUCTURAL MASONRY BUILDINGS ABOVE CONCRETE FLOOR STRUCTURE


  • Leader : JOEL ARAUJO DO NASCIMENTO NETO
  • MEMBRES DE LA BANQUE :
  • JOEL ARAUJO DO NASCIMENTO NETO
  • DANIEL NELSON MACIEL
  • PETRUS GORGONIO BULHOES DA NOBREGA
  • GUILHERME ARIS PARSEKIAN
  • Data: 29 juin 2018


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  • A problem involving structural masonry refers to the impossibility of reforms. Partial or total removal of structural masonry walls may result in cracking, excessive spans or even progressive collapse of the structure. However, there are few studies about the behavior of structural masonry, in terms of stress redistribution, through inadvertent structural wall removals, as well as the possible progressive collapse associate with these situations, especially in structural masonry buildings above concrete floor structure. Thus, it becomes evident the importance of more studies about this topic. This research aimed to evaluate the stress redistribution and their implications in other elements of the structure, such as reinforced concrete masonry lintels, as well as to evaluate the influence of the concrete floor structure in this redistribution, indicating the verifications to be made for the progressive collapse study in these structures. For this, two buildings were modeled in SAP2000® commercial software using the equivalent frame model. The stresses were evaluated at the base walls and at vertical cross sections, in addition to the normal forces in the lintels, on near floors to the occurrence of removal walls caused by supposed inadvertent reforms. The results showed that: the stresses dissipate considerably along the floors from which the removals are considered; the masonry lintels have an important function in the stress redistribution, among other conclusions.


17
  • ANA PAULA SOBRAL DE FREITAS
  • BEHAVIOR OF PILED RAFT FOUNDATION FOR WIND TURBINE


  • Leader : OSVALDO DE FREITAS NETO
  • MEMBRES DE LA BANQUE :
  • ALEXANDRE DUARTE GUSMÃO
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • OSVALDO DE FREITAS NETO
  • WILSON CARTAXO SOARES
  • Data: 10 juil. 2018


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  • The evolution in the power wind turbines in recente years, with the inherent increase in blade diameter, has led to a significant increase in the height of the towers, which are currently over 120m. As a consequence, is required a performance foundations compatible with increasing vertical and horizontal efforts as well as the bending moments. It is observed that the foundations projects that demand large blocks associated with piles, sometimes used as solutions wind tourbine foundations, are mostly oversized because they do not consider the contribution of the block as an element of transmission of load to the ground foundation. That is, it is considered that the block has the only function of transmitting the loading of the wind turbine to the piles, and the project is conceived as a solution in group of piles. This research will use a numerical modeling software specifically for geotechnics, in this case the Plaxis® 3D Foundation v1.1. The objective of this work is to analyze the load distribution between piles and raft, as well as the differential settlements in the piled raft system foundation while are done simulations varying the number and positioning of the piles below raft.


18
  • ALAMANDA THAISE DE OLIVEIRA ARAÚJO
  • STUDY OF HISTORICAL BUILDING MASTERS - RELIGIOUS ARCHITECTURE - OF THE COLONIAL PERIOD, IN RIO GRANDE DO NORTE, WITH EMPHASIS IN THE CONSTRUCTION SYSTEMS AND PATHOLOGICAL MANIFESTATIONS


  • Leader : MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • MEMBRES DE LA BANQUE :
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • ANDREZA KELLY COSTA NOBREGA
  • Data: 26 juil. 2018


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  • A historical building has great importance for its characteristics and relevant values that portray the history of a particular people or social group over time, forming a kind of identity. In recent years, several old buildings have suffered damage representing irreparable losses. Therefore, in order to guarantee the enjoyment of these constructions in present and future generations, it is necessary to preserve them. In order to do so, it is essential to be aware of some attributes, such as: its conception, the construction techniques used in its construction, the alterations suffered and, finally, its current state, with the survey of the processes of property degradation. In this way, the combination of scientific and cultural knowledge with the experience for the study of all the architectural patrimony becomes ideal, which demands a multidisciplinary approach. In this context, civil engineering enters as a scientific support - analyzing the attributes - in the field of Restoration to achieve this result. In view of this, the study, carried out in a regional scope - state of Rio Grande do Norte -, analyzed in a qualitative way the characteristics of the masonry of the Church of Our Lady of the Presentation, Natal-RN; of the Church of Our Lady of the Rosary, Acari-RN; and the Church of Nossa Senhora do Ó, Serra Negra do Norte-RN. The method used was based on the study of the historical dimension - using the concept of Constructive System - and the formal dimension, through inspection of masonry made in loco. As a result, the systematization of information regarding masonry was obtained, as well as the elaboration of a GUT Matrix that can assist Restoration professionals, identifying the most relevant damages of each building. In this way, the Church of Our Lady of the Presentation, visually, is in better conditions of operation and use than the others, being the one with the highest historical value among them. The Church of the Rosary eventually works and shows a lack of care for the patrimony, presenting a greater magnitude in the pathological manifestations. Finally, in the Church of Our Lady of the Oth, there is a serious problem of presence of humidity, which is causing other damages and degrading the building, needing to undergo urgent repair activities. In addition, it was possible to conclude that historic buildings have a regular degree of conservation, and although they have undergone significant interventions recently, they present a reasonable amount of pathological manifestations that degrade the historical patrimony and diminish its useful life.


19
  • MICHEL RODRIGUES CÂMARA
  • NÃO INFORMADO.

  • Leader : ADA CRISTINA SCUDELARI
  • MEMBRES DE LA BANQUE :
  • ADA CRISTINA SCUDELARI
  • MARIA DE FATIMA ALVES DE MATOS
  • VENERANDO EUSTAQUIO AMARO
  • RICARDO NASCIMENTO FLORES SEVERO
  • Data: 30 juil. 2018


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  • In the present work geoprocessing technics were used through digital image processing and multi temporal geographic analysis on a three decade time scale, using remote sensing images of 30 meters and 5 meters of spatial resolution to identify areas which suffered cliffs retreat of the coast of Rio Grande do Norte-Brazil, measure in m² the retreat and loss of initial characteristics of these environments, as well as to identify and analyze the socio-environmental impacts present. Five cliff areas retreat were found, with set back up to 78,061.61 m², putting at risk areas of heavy urban occupation, infrastructures facilities and access roads. Such information subsidize coastal management on these environment of the coast of Rio Grande do Norte.

20
  • DANIELA DA FONSECA FERREIRA
  • Retaining walls

  • Leader : CARINA MAIA LINS COSTA
  • MEMBRES DE LA BANQUE :
  • CARINA MAIA LINS COSTA
  • JESELAY HEMETÉRIO CORDEIRO DOS REIS
  • JOSE NERES DA SILVA FILHO
  • Data: 30 juil. 2018


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  • Deterministic methods are traditionally adopted for reinforced soil structures design, similarly to other types of Geotechnical Engineering structures. This design method does not adequately consider the inherent uncertainties associated to both, the construction work and the variability of the soil and other used materials. Following the deterministic approach, safety factors that promote separation between the mean values of resistance and applied loads are typically used. Nonetheless, reliability based design allows considering uncertainties using statistical tools, which provides a rational way to incorporate uncertainties into geotechnical design. According, the present work intends to evaluate the behavior of geosynthetic-reinforced soil (GRS) wall using reliability analysis, considering sand as backfill and geotextiles, as reinforcement layers. The study was conducted for external and internal failure mechanisms. Different methods of reliability analysis were used, specifically, the first order reliability method (FORM) and point estimate method (PEM). Parametric analyzes were performed in order to evaluate the influence of the variables involved in the problem with respect to the value of the reliability index. The coefficient of variation for the tensile strength of different types of geotextiles was obtained by analyzing the results of tensile tests and creep rupture tests of geotextiles commercially available in Brazil. The results showed that the increase in the coefficient of variation of both the tensile strength and the friction angle provided the decrease of the reliability index related to the internal stability of the structure. In addition, structures using woven geotextiles have resulted in higher reliability index than those designed with non-woven geotextiles. The higher the height of the structure the lower the reliability index. For all failure modes related to external stability and for pullout failure, the FORM method resulted in higher reliability index values than the PEM method, indicating that the point estimates method is more conservative in relation to the first order method. Nevertheless, for the geosynthetic rupture failure mode there was no well-defined trend regarding the more conservative method for calculating the reliability. Overall, reliability based design for GRS walls was found to provide consistent results, corresponding to a conceptually more adequate design approach.


21
  • THAÍS SOUSA LUCENA
  • Geostatistical analysis of static resistance predicted from SPT test results.

  • Leader : YURI DANIEL JATOBA COSTA
  • MEMBRES DE LA BANQUE :
  • ALEXANDRE DA COSTA PEREIRA
  • JOSE NERES DA SILVA FILHO
  • YURI DANIEL JATOBA COSTA
  • Data: 30 juil. 2018


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  • Prediction of the soil static resistance is primordial in foundation engineering design projects. Use of methods for prediction of pile bearing capacity based on standard penetration test (SPT) results is a common practice. Simplicity and low costs make the SPT one of the most employed tests in geotechnical investigation. In the last four decades, the mechanisms of energy transfer within the test have been studied by several authors, who were motivated by questions related to the dispersion of the  blow-count values. It has been verified that knowing the test energy efficiency allows to normalize the SPT blow-count resistance to a standard reference value. In this context, Aoki and Cintra (2000) investigated the dynamic SPT hammer blow event by means of the Hamilton’s energy conservation principle. The study was a theoretical background to the methodology put forward by Aoki (2013), which allows to quantify pile tip and side friction resistances from the SPT test results. The method can be applied to tests in which the efficiency and the length of the recovered of soil samples are known. In the present study, predictions of pile tip and side friction static resistances were achieved by using the methodology of Aoki (2013) and the results of 58 SPT tests. Borings were carried out in a site composed of fine sand layers. All tests had the length of the recovered samples measured. An additional SPT test was also carried out, which included six static pullout tests on the SPT sampler, in order to investigate the lateral skin friction of the sampler. The ratio between the internal and the external skin friction of the sampler, known as the “a” parameter, was close to two for fine sand and increased for deeper layers with higher percentage of fines. Finally, a comparison was made between the results of resistance predicted by Aoki (2013) method and the results of eight CPT tests performed at the same site. Comparisons between predicted and experimental results were based on concepts of Geostatistics. Specifically, an analysis of the spatial behavior of the static resistance was conducted using the software Geokrige, which made calculations of variograms and spatial inferences by ordinary kriging. Predictions of tip and side friction static resistances based on SPT tests were found to be consistent.

22
  • FELIPY LIMA DE QUEIROZ
  • Evaluation of installation and performance of an instrumented helical pile in a sandy soil deposit
  • Leader : YURI DANIEL JATOBA COSTA
  • MEMBRES DE LA BANQUE :
  • JOHN ELOI BEZERRA
  • JOSE NERES DA SILVA FILHO
  • YURI DANIEL JATOBA COSTA
  • Data: 31 juil. 2018


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  • Helical piles are foundation types used to support compressive, tensile, or lateral loading. The capability of being loaded right after installation, the high production rate and the possibility of reutilization in different projects are a few advantages of helical piles. Despite the increasing use of helical pipes, the amount of data collected from field experiments with instrumented helical piles is still relatively small. In this work, the tensile behavior of an instrumented helical pile embedded in a sandy soil deposit is evaluated along the effect of disturbance caused in the ground after installation. The three-plate pile used in this investigation was instrumented with electric resistance strain gages attached to five distinct sections along its shaft. Two sections were used for measuring torque and the other three sections were used for measuring axial load. The performance of the instrumented pile was monitored during installation by measurements of the installation torque. The axial load in the instrumented sections was monitored during two static pullout tests. The disturbance caused by pile installation was evaluated with the results of tests with a dynamic cone penetrometer (DCP) and by radargram renderings from a ground penetration radar (GPR). Measurements of the installation torque along with the pullout test responses resulted in torque factors lower than the typical values found in the literature. Results of the instrumented sections showed that the contribution from the top helical plate in the overall bearing capacity is smaller than that from the truncated cone between the bottom and top plates. The results from the DCP and GPR apparatuses suggest that the passage of the helical plates during pile installation reduced soil compaction within a zone of influence from the shaft of approximately three times the diameter of the largest plate.

     

23
  • EDUARDO EILER BATISTA DE ARAÚJO
  • EVALUATION OF WATER RETENTION CAPACITY OF GREEN ROOFS WITH APPLICATION OF GEOSYNTHETICS

  • Leader : FAGNER ALEXANDRE NUNES DE FRANCA
  • MEMBRES DE LA BANQUE :
  • FAGNER ALEXANDRE NUNES DE FRANCA
  • ADA CRISTINA SCUDELARI
  • JOANA DARC FREIRE DE MEDEIROS
  • ALEXANDRE DA COSTA PEREIRA
  • Data: 31 juil. 2018


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  • Population growth of urban areas produce diverse environmental impacts, such as increase in the probability of flooding, heat island effect e pollution. The urbanization demands buildings, which leads to soil waterproofing. This increase in impervious surface area might turn great urban space into areas more susceptible to flooding when occurrence of intense rain. Therefore, the green roofs emerge in the worldwide scenario as an alternative to mitigate flooding. In addition to storm-water management, green roofs also offer other benefits (e.g. thermal benefits, noise reduction, aesthetic appeal, air pollution). Although usage of green roofs is considered an ancient technique, the green roofs studies increased by the 2000s. The performance of green roofs depends on constructive and environmental aspects. Therefore, the main objective of this study is to evaluate the water retention capacity of a green roof prototype with geosynthetics by means of simulated rain for climatic conditions of Natal, Rio Grande do Norte, Brasil. In this study, it is also expected to assess the performance of the green roofs in function of drought period, with admeasurement of moisture content antecedent rain simulation and in function of duration and intensity of the simulated rain.

24
  • GERVASIO ARAUJO SOUTO NETO
  • TARGET COSTING, AN APPLICATION EXAMPLE IN A ART AND CULTURE SPACE

  • Leader : REYMARD SAVIO SAMPAIO DE MELO
  • MEMBRES DE LA BANQUE :
  • DAYANA BASTOS COSTA
  • LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • REYMARD SAVIO SAMPAIO DE MELO
  • Data: 4 déc. 2018


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  • The traditional forms of development of Brazilian public projects are targets of social dissatisfaction because they cannot align the delivered value of the product with the desired value of the end-users. Target Costing (TC) is a cost management strategy that seeks to reduce cost wastage to reach the target cost and increase the value delivered, as desired by future users. Its applications present excellent results in the world civil construction, especially when there is the Public Engagement (PE) from the beginning of the product design. However, no results of its application in works of the Brazilian public sector are known. The main objective of this research is to apply the TC strategy in a Brazilian federal public project. In order to operationalize the TC strategy, a Value Methodology (VM) approach was used, adapted from Moraes (2017), which proved adequate for the construction context. The methodology of the research was Design Science Research (DSR) and two exploratory case studies supported it: a pilot case study, building an office kitchen, to understand the process of development of public works; and a main case study of the construction of an “Art and Culture Space” (ACS) to implement the TC strategy. As a result, the research was able to achieve the cost goal by reducing unnecessary costs (21.28%) and employing improvements that add value to end-users. Despite this, the proposed method still needs to be tested for other works of the same context.

25
  • ANA BEATRIZ AZEVEDO DE MEDEIROS
  • NÃO INFORMADO

  • Leader : MARIA DEL PILAR DURANTE INGUNZA
  • MEMBRES DE LA BANQUE :
  • MARIA DEL PILAR DURANTE INGUNZA
  • ANTONIO CARLOS GALINDO
  • RUBENS MARIBONDO DO NASCIMENTO
  • MARIO TAVARES DE OLIVEIRA CAVALCANTI NETO
  • Data: 20 déc. 2018


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  • NÃO INFORMADO

2017
Thèses
1
  • FRANCISCO DAS CHAGAS DA COSTA FILHO
  • TECHNICAL FEASIBILITY STUDY OF USING WASTE FROM SCHEELITE PROCESSING IN COMPOSITION OF ASPHALTIC CONCRETES

  • Leader : MARIA DEL PILAR DURANTE INGUNZA
  • MEMBRES DE LA BANQUE :
  • MARIA DEL PILAR DURANTE INGUNZA
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • ENIO FERNANDES AMORIM
  • LUIS FERNANDO MARTINS RIBEIRO
  • Data: 3 févr. 2017


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  • The Brazilian mineral production is an extremely important activity for the country's economy, since in addition to contributing to gross national product - PIB, it is responsible for the generation of many direct and indirect jobs. Therefore, the Tomaz Salustino Corporation Mining (Brejuí Mine) is a important northeastern representative of this sector. Data for 2012 show that the production of the Brejuí Mine was around 20 tons per month (MACHADO 2012), representing more than 300 jobs generated, in addition to the development of the municipality where the company is located. However, due to the ore (scheelite) processing, since 1943, tons of waste have been generated, and it is currently estimated around 7 million tons (4.5 million thick fractions and 2.5 million fine fractions), disposed in piles and waste basins, generating several environmental impacts, such as the modification of the local landscape. Due of this large stock of waste, jointly with the great extraction of natural raw material to compose the usual layers of a pavement, the present study evaluated the technical feasibility of the residues from the Brejuí Mine in the composition of asphaltic concretes, replacing the natural small aggregate by the thick fractions of the residue, and the conventional filler by the fine fractions of the residue. For this, chemical and mineralogical characterization of fractions of the residue and of the natural aggregates used in the research, besides Marshall dosages in compositions of asphaltic concretes was carried out to analyze the volumetric parameters and the stability of the materials as for the use in road works. From the proposed experimental program, it can be verified that the thick fractions of the scheelite processing residue presented a high potential to be used in natura as a small aggregate, because the analyzed specimens showed good performance in relation to the volumetric parameters and the Marshall stability. The fine fraction has also proved feasible to be used as an artificial filler, however, for this application, it is necessary to improve the quality for that the fraction of the residue fits as asphalt mixtures filling material since, in natura, it did not present the 65% passing material in the 0.075 mm sieve required by DNER - EM 367/97 (BRASIL, 1997).

2
  • TERCIO PEREIRA JOVEM
  • ANALYTICAL AND NUMERICAL STUDY OF LIVE LOAD DISTRIBUTION IN REINFORCED CONCRETE BRIDGE

  • Leader : JOSE NERES DA SILVA FILHO
  • MEMBRES DE LA BANQUE :
  • ADA CRISTINA SCUDELARI
  • DANIEL NELSON MACIEL
  • HIDELBRANDO JOSE FARKAT DIOGENES
  • JOSE NERES DA SILVA FILHO
  • Data: 24 févr. 2017


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  • The bridges are essential to road and rail transport systems, especially in Brazil where these are very relevant. In this context, it inserts the structural system of bridges with multiple main spars which occupies a prominent place in the world to be relatively simple and efficient, with economic and constructive advantages notably known. Nevertheless, there are few studies that aim to optimize the distribution of loads of the bridges that take into account the flexural rigidity of the stringers.Thus, this study aimed to analyze a bridge with three, five, seven and eight beams. The models were assessed by analytical methods of distribution of loads, most used, of Engesser-Courbon, Leonhardt, Guyon-Massonet Homberg-Trenks and Fauchart, and compared with models in finite element modeled in software SAP2000 and CSi Bridge V18. The analytical methods have limitations in consideration of torsional stiffness or, in some cases, even such behavior is neglected. The discretized models in finite elements (bar elements and plate on flat and three-dimensional behavior) represented the best behavior of the bridge, as it allowed us to consider the joint operation of the structure.

3
  • CINTHIA MAIA PEDERNEIRAS
  • EVALUATION OF INTERCONNECTED BLOCKS WITH RECYCLED AGGREGATES FROM RESIDUES OF CONSTRUCTION AND DEMOLITION OF WORKS OF THE MUNICIPALITY OF NATAL/RN
  • Leader : MARIA DEL PILAR DURANTE INGUNZA
  • MEMBRES DE LA BANQUE :
  • ADA CRISTINA SCUDELARI
  • ENIO FERNANDES AMORIM
  • JUZÉLIA SANTOS
  • MARIA DEL PILAR DURANTE INGUNZA
  • Data: 25 févr. 2017


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  • This work aims to analyze the use of construction and demolition waste in Natal/RN as recycled aggregates for precast concrete paving blocks. In the first stage, the detailed characterization of the aggregates (fine and coarse) was carried out. The tests used for this purpose were grading curves, bulk density, dry specific density, pulverulent material, organic material, water absorption, swelling, X-ray fluorescence (FRX), X-ray diffraction (XRD) and electron microscopy of Scanning (SEM). From the characterization tests of natural and recycled aggregates is possible to analyze physical, chemical and microscopic properties. Ten different mixes were analyzed with an effective water/cement ratio of 0.4 for recycled rates of coarse and fine aggregates of 100%. This research analyzed the conditions of the recycled aggregates in the mixture (dry, washed and saturated), evaluation of the performance of aggregates in a concrete mix. The tests to analyze the technical viability of the concrete blocks, according to the specific norm NBR 9781 (2013), were compressive strength (at ages of 7, 14, 28 and 270 days) and water absorption. To evaluate the durability, a prototype was constructed, which was analyzed after one year of construction. The blocks made with only recycled sand showed an increase in the results of compressive strength when compared to the reference blocks. The blocks made with recycled coarse obtained the smallest resistance. It was also observed that when the recycled aggregates are washed present better performance in the final product. The results obtained were satisfactory for the application of the blocks in streets of low movement and low load. With the intense growth of waste from civil construction, the relevance of this research is proposes the manufacture of a sustainable product that aims to minimize the use of natural resources and promote a proper destination for the waste generated.

4
  • ALEXANDRE GURGEL DAMASCENO
  • Combining Finite Elements Method and Particle Swarm Optimization in the Analysis of Nonlinear 2D Frames

  • Leader : DANIEL NELSON MACIEL
  • MEMBRES DE LA BANQUE :
  • DANIEL NELSON MACIEL
  • HIDELBRANDO JOSE FARKAT DIOGENES
  • PAULO DANTAS SESION JUNIOR
  • Data: 26 févr. 2017


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  • This research develops and explores the possibility of resolution, considering the effects of geometric non-linearity, of beams and planar porticoes, combining the Finite Element Method in the Positional Formulation (MEF-P) and Particle Swarm Optimization (OEP), known in the specialized literature by Particle Swarm Optimization (PSO). The deformations of several structures are analyzed, comparing them with the values of deformations presented when solved by the MEF in the positional formulation, using the method of Newton Raphson. A comparison is also made with the results provided by the Classical Beam Kinematics (Euler-Bernoulli), in cases where the structures were in a regime of small displacements. Processing cost and accuracy are also presented in charts for various structures. Particle swarm optimization was able to find adequate values for the deformation of several structures, however the cost of processing fell short of expectations, contradicting several records in the specialized literature. Considerations about the result and proposals for deepening are recorded, highlighting that the coupling of such different methods (MEF and EPO), being a deterministic and another stochastic, is an open proposal that considers the need to test interdisciplinary solutions to problems each time More complex in the area of structural analysis.

5
  • ANDERSON ALBINO FERREIRA
  • Computational Modeling for Evaluation of the Non-Fill Effect of Vertical Joints in the Strength of Structural Masonry.

  • Leader : DANIEL NELSON MACIEL
  • MEMBRES DE LA BANQUE :
  • DANIEL NELSON MACIEL
  • JOEL ARAUJO DO NASCIMENTO NETO
  • ANDREA BRASILIANO SILVA
  • HIDELBRANDO JOSE FARKAT DIOGENES
  • Data: 3 mars 2017


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  • Masonry is a composite material, consisting basically of units and mortar joints (vertical and horizontal), and may also be associated with other materials, such as steel and grout. In Brazil, from the 1980s, structural masonry consolidated itself as a highly productive, rational and economical construction system due to characteristics as: simplification of execution techniques, less diversity of materials employed, reduction of labor and speed execution. In structural masonry, one of the execution possibilities that can be explored is the non-filling of vertical joints, also called dry joints. The adoption of this practice generates certain advantages as the reduction in the execution time of the construction, the reduction of the consumption of materials and the minimization of the cracking caused by the intrinsic deformations, such as retraction and thermal deformations. However, despite be employed to some years in country, the implications of its use often has been not properly considered in the projects, this is due to the fact that there is few research that deals with this subject. Moreover, the existing researches sometimes present results that diverge from each other, mainly with respect to the resistance to compression and shear. In this work, numerical simulations of small walls of ceramic and concrete units, with and without vertical joints, were carried out in accordance with the requirements of NBR 15812-2 (2010), NBR 15961-2 (2011) and NBR 14321 (1999). The purpose of this work was to evaluate the influence of non-filling of vertical joints on the compressive strength and shear strength of the masonry.

6
  • ARTHUR DA SILVA REBOUCAS
  • LIVE LOAD DISTRIBUTION ANALYSIS IN CURVED REINFORCED CONCRETE BRIDGE

  • Leader : JOSE NERES DA SILVA FILHO
  • MEMBRES DE LA BANQUE :
  • JOSE NERES DA SILVA FILHO
  • FRANCISCO ADRIANO DE ARAUJO
  • JOEL ARAUJO DO NASCIMENTO NETO
  • ALINE DA SILVA RAMOS BARBOZA
  • Data: 24 mars 2017


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  • Nowadays, due to the density of cities and the demand for infrastructure, the need to build bridges and curved viaducts has intensified. However, the structural analysis of this bridge deck geometries still needs more contributions, especially in optimization of load distribution in this type of deck or in the comparison between the use of straight and curved girders, in beam and slab and box girders bridges. Therefore, the main objective research is analyze the behavior of 3 different structural systems of curved reinforced concrete bridges, evaluating the bending moment live load distribution in the most critical longitudinal position of the structure. To identify this position, the influence lines were determined as a function of the radius of curvature and the length of each bridge studied. Afterwards, 15 numerical models were constructed using FEM by CSI Bridge V17 program and an analysis of existing analytical models for curved beam and slab bridges (V-Load method) and curves box girder bridges (M/R method) was performed in order to evaluate the variation of the live load distribution varying the curvature of the bridge centerline, the existence or not of support diaphragms and the structural analysis method. All the studies were performed using Brazilian truck load “TB-450” defined by NBR 7188: 2013. The analytical methods presented overestimated results in all cases analyzed for the outside girders. The live load distribution of bending moment is optimized through the insertion of support diaphragms, in bridges wtih tee beams, such distribution presents a greater variation of load share than in bridges with box girder section, in which there is an approximate equal distribution. In addition, it was found that in all structural systems, with increase of the curvature, there is an increase in the load distribution factor at the outside girder.

7
  • RAFAELA LOPES DA SILVA
  • A study of nonlinear 2D-frames considering thermic effects

  • Leader : DANIEL NELSON MACIEL
  • MEMBRES DE LA BANQUE :
  • DANIEL NELSON MACIEL
  • JOÃO CARLOS ARANTES COSTA JÚNIOR
  • MARCELO GRECO
  • Data: 24 mars 2017


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  • This work presents a study considering the thermal effects in the dynamic behaviour of nonlinear 2D-frame structures (physical and geometric), in which the effects of bending and shear are predominant. A formulation substantiated on the first and second laws of thermodynamic and the Helmholtz free-energy is presented in this work to consider the thermic effects on this type of structure. The Finite Element Method based on nodal positions, rather than nodal displacements, is used as structural analysis tool. The solution of the nonlinear dynamic problem is given through the combination of Newton-Raphson iterative process with several explicit and implicit time integration methods, wherein the numeric results are compared with the ones found on specialized literature. As well, it is presented a description of one technique to solution of impact problems.

8
  • DAVID ESTEBAN DIAZ TAQUEZ
  • Susceptibility to the Occurrence of mass movements and evaluation of the stability of cliffs under unsaturated condition: case study in the center of launches from Barreira do Inferno – Brazil

  • Leader : OSVALDO DE FREITAS NETO
  • MEMBRES DE LA BANQUE :
  • OSVALDO DE FREITAS NETO
  • ADA CRISTINA SCUDELARI
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • ROGER AUGUSTO RODRIGUES
  • Data: 30 mars 2017


  • Afficher le Résumé
  • The aim of this research is to evaluate the susceptibility conditions to the occurrence of mass movements and slope stability of the studied area using the method of Strength Reduction Method ou SRM, on unsaturated conditions in the Northeast of Brazil. For the analysis of the susceptibility to the occurrence of mass movements, the methodology called the Analytic Hierarchy Process was used along with the GIS geographic information systems. In order to determine the resistance parameters of the soils, triaxial compression tests were carried out under saturated conditions CU and triaxial compression tests CW were performed for the residual moisture condition. For the determination of soil retention curves, the filter paper method was considered, equations by Chandler et al. (1992), and the adjustment of the retention curves developed by Van Genuchten (1980). From the results of the triaxial tests, the prediction of the shear strength of the unsaturated soils was performed using the hyperbolic model proposed by Vilar (2007). Then, from the susceptible sections to the occurrence of mass movements and the resistance parameters of the studied soils, analyzes of slope stability were applied with the intention of quantify the safety factor of the same. The method used in the stability analyzes was the SRM, implemented in the OPTUM Software, considering different saturation conditions, as follows: soil under natural field saturation condition, soil with 50% degree of saturation, and finally Completely saturated soil. The analysis also took into account the presence of layers of cemented soil and traction cracks present in the upper part of the cliff. The slope was divided into three sections with predominant soils, which were positioned at the base of the intermediate section, and at the top of the cliff, called soil-1, soil-2, and soil-3 respectively. These soils were characterized as clayey sand (SC), silty sand (SM) and poorly graded sand (SP). As for the retention curves, the three soils present bimodal behavior, typical of soils with granulometry of material with micropores and macropores. Finally, the results obtained from these numerical analyzes were initially related to the model of susceptibility produced from the AHP-GIS methodology, concluding that this model is in good agreement, evidenced by the results of the numerical analysis and by the vestiges of Movements observed in the field. The results of the numerical analyzes were also related to the types of mass movements, presenting as an outcome that both geomorphological factors and degrees of saturation result in different types of movements for the characteristic sections of these geomorphologies (cliffs). Verifying in this way the movements suggested in the studies of Santos Jr (2004) and Souza Junior (2013), where three types of profiles with different morphologies and their possible mass movements, toppling, fall of blocks and landslides were related.

9
  • ANDRIELE NASCIMENTO DE SOUZA
  • ANALYSIS OF THE AÇU DAM BEHAVIOR DURING ITS CONSTRUCTION, FIRST FILLING AND OPERATION OF THE RESERVOIR

  • Leader : OLAVO FRANCISCO DOS SANTOS JUNIOR
  • MEMBRES DE LA BANQUE :
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • OSVALDO DE FREITAS NETO
  • RAIMUNDO LEIDIMAR BEZERRA
  • ROBSON PALHAS SARAMAGO
  • Data: 30 mars 2017


  • Afficher le Résumé
  • The Açu Dam is an important geotechnical built in Rio Grande do Norte and in Northeast Brazilian, especially because of its size and complexity. In addition to its size and importance, it has gained prominence in the national and international literature because of the collapse in upstream slope in the end of construction period. This paper aimed to analyze its behavior in stages of dam construction, first filling and operation of the reservoir. In each step, were analyzed: the stress-strain behavior, the flow and the pore-pressure variation, and the slope stability. These analyses were performed with the software Sigma/W, Seep/W and Slope/W, which are components in a suite of geotechnical products called GeoStudio, produced by Geo-Slope International Ltd. The results were compared with the instrumentation dates available in Rocha (2003). In the comparative analysis of vertical displacements, the largest difference between modeling results and instrumentation data was 8.9 cm, in the T7 extensometer, at the end of the first filling. In the stability analysis, the lowest safety factor was 1.3 for the upstream slope in the reservoir operation phase, but the media of the safety factors obtained by the methods based on limit equilibrium was 2.4. For a downstream slope, this factor was equal to 1.6 in all stages. These results confirm the dam stable condition. In pore-pressure analysis, the pneumatic piezometers presented greater divergences between modeling and instrumentation than those of the Casagrande type. The most significant difference was 46% (23 kPa), in the PZP1 piezometer, at the first filling of the reservoir. However, considering the differences obtained by other authors who also studied the water flow in this dam, we conclude that the results of the present analysis are satisfactory and that the adopted parameters are adequate to characterize the soils modeled.

10
  • RUAN LANDOLFO DA SILVA FERREIRA
  • Effects of the incorporation of recycled construction and demolition waste (RCD) sand into composite mortars
  • Leader : ANDREZA KELLY COSTA NOBREGA
  • MEMBRES DE LA BANQUE :
  • ANDREZA KELLY COSTA NOBREGA
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • ENIO FERNANDES AMORIM
  • WALNEY GOMES DA SILVA
  • Data: 31 mars 2017


  • Afficher le Résumé
  • The construction, remodeling and demolition process can cause significant problems to the environment due to the extraction of raw materials and an inadequate disposal of the waste generated. In particular, construction and demolition wastes (CDW), which commonly correspond to more than half of urban solid waste, have as main destinations, vacant lots, roadsides and rivers, causing serious environmental, social and economic impacts. Currently, a recycling of recycled aggregates (RA), especially of mixed composition has been studied to lesser extent when compared to RA of concrete. Therefore, because it does not have alternatives for their use, a large amount of this type of recycled aggregate is stored by plants. In this sense, the aim was to analyze the technical and economic viability of the use of RA with different grain size and washed quality 

    compositions, at 25, 50, 75 and 100% substitution levels of the natural aggregate (NA), in the production of mixed mortars. For the production of mortars, CP II Z-32 cement, lime CH-I and a volume ratio of 1:1: 6 were used. Water content was adjusted to mixtures with a consistency of 260 mm. Initially, the physical, chemical and microstructural properties of the aggregates and the fines fraction (<0.15 mm) were analyzed. Seeking to evaluate the technical feasibility of the mortar tests were carried out in the fresh state, which looked at the consumption of water, water retention, bulk density and air content embedded; and hardened mortar, compressive strength, flexural strength, dynamic modulus of elasticity, water absorption by capillarity, immersion absorption, adherence strength, susceptibility to cracking. The cost of production of 1 m³ of mortar was used for an assessment of technical feasibility. It was showed that, as mortars with RA, regardless of their size distribution or condition, presented higher water consumption, lower bulk density and incorporated air content, as well as water retention capacity. In hardened mortar, such as mortars possessing RA with a presence of fines and not washed, more resistant, more rigid and less permeable. However, the performance of the coatings relative to the potential of adhesion to the substrate and a number of cracks has been lower, confirming a premise that the use of RA with fines is not indicated for coating mortars. As for the technical feasibility, to incorporate RA, the cost to produce 1 m³ of mortar decreases. As a conclusion, it is recognized that the use of RA for the production of coating mortars is feasible, especially when aggregates with adequate granulometric composition and absent of fines are available.

     

     

11
  • NATHALIA MARINHO BARBOSA
  • nao consta

  • Leader : OLAVO FRANCISCO DOS SANTOS JUNIOR
  • MEMBRES DE LA BANQUE :
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • OSVALDO DE FREITAS NETO
  • MARCOS BARRETO DE MEDNONÇA
  • Data: 31 mars 2017


  • Afficher le Résumé
  • This Dissertation treat of obtaining geotechnical properties of sediments of Barreiras Formation and the stability analysis of the cliffs located at the Barreira do Inferno Launches Center, Parnamirim, Rio Grande do Norte State. Coastal areas attracts great interest for the population in general, and developments in these regions are quite common, causing erosive processes to be studied in order to provide a better understanding of the factors influencing the Stability of the cliffs and consequently their safety. The study site in question, being a protected military area, is completely free of human interference and without any edification at its top, making the analysis representative of natural conditions imposed on the slopes studied. The activities developed during the elaboration of this dissertation are grouped in four stages: bibliographic revision, fieldwork, laboratory tests and stability analysis of the cliffs. Based on visits accomplished in situ, information was collected for the subsequent retrieval of the critical profiles of the cliffs for stability analysis. It was observed that the profiles in general aren’t steep, with the presence of basal incision in some areas. It was verified in analyzes that the tensile tensions acting are low. The main mechanism responsible for triggering the instability processes is basically the soil saturation caused by rainfall, which decreases its resistance and generates mass movements. From the tests carried out, it was observed that the cohesion of the saturated soils is around 26% of the soil cohesion in the natural moisture content. However, the angles of friction in both cases suffer inexpressive variations It was concluded that the presence of the basal incision had no significant effect on the reduction of stability in the configurations analyzed by the limit equilibrium methods, while stress analysis showed an increase in tensile stresses on the face of the section. The study of the stability analysis performed in this work effectively represented the types of rupture observed in the cliffs of the coast of Rio Grande do Norte, being more coherent than those obtained by traditional methods.

12
  • LARISSA VERAS TORQUATO SENA
  • Contribution to the dimensioning of bearing beams.
  • Leader : ADA CRISTINA SCUDELARI
  • MEMBRES DE LA BANQUE :
  • ADA CRISTINA SCUDELARI
  • DANIEL NELSON MACIEL
  • FRANCISCO ADRIANO DE ARAUJO
  • JOSE ANTÔNIO MARQUES CARRER
  • Data: 10 juil. 2017


  • Afficher le Résumé
  • Cranes and their crane runway girder are essential components of various industrial operations and other segments. Each crane and its crane runway girder form a mechanical structural system of material handling. Although the equipment is widely used in industrial buildings, there are very few papers and researches in the sizing phase of beams. In order to assist professionals and students in the area of steel structures to carry out the verification of the dimensioning of the crane runway girder with bracing between supports, this paper presents the following criteria of the project according to NBR 8800 (ABNT, 2008). The objectives of this very research include the procedure for determining project loading demand and project resistances, a verification of the ultimate limit state and the serviceability limit state, localized and fatigue strength checks, and the design of stiffeners welded to the web of the profile of the crane runway beams. In the end, a spreadsheet was developed for didactic and academic purposes through Excel, a commercial applet (Microsoft Corporation), with a calculation methodology addressed. For a calibration of the applet, four examples among the specific literature were considered, beware of this, the concept of crane runway girder dimensioned by NBR 8800 (ABNT, 2008) was also evaluated.

     

     

13
  • DIDONEY FERNANDES VILHETE
  • BACK ANALYSIS OF AÇU DAM UPSTREAM SLOPE FAILURE AT THE END OF THE CONSTRUCTION PERIOD

  • Leader : OLAVO FRANCISCO DOS SANTOS JUNIOR
  • MEMBRES DE LA BANQUE :
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • OSVALDO DE FREITAS NETO
  • FRANCISCO CHAGAS DA SILVA FILHO
  • RAIMUNDO LEIDIMAR BEZERRA
  • Data: 8 août 2017


  • Afficher le Résumé
  • The risks associated with dam failure are high. Problems of instability involving this frameworks bring catastrophic consequences to the society. The Açu dam is a geotechnical embankment with significant importance in the Northeast, mainly in Rio Grande do Norte state. It is the largest dam in the state and has gained prominence in the national and international literature with the slice of the upstream slope at the end of the construction period. In cases of failure, back analysis is a reliable and economic technique to calculate the shear strength parameters of the soil in order to avoid similar cases. From the evaluation of strength data available in the academic environment, this work had as purpose to analyze the failure occurred to obtain the average shear strength parameters of the black clayey material that constituted the Açu dam core before the accident occurred. In the first stage of the work the slope stability of the dam was analyzed and in the second stage the deterministic and probabilistic back analysis. The analyzes were performed in Slide 7.0 belonging to Rocscience platform. The results were compared to the data available in Mello (1982); Penman (1985) and Rocha (2003). At the end of the research it was possible to define the possible average shear strength values of black silt clay and to establish the causes and mechanisms of dam failure. Stability analyzes showed that the slope would fail with strength parameters of the black silt clay in the saturated condition, with values of probability of failure ranging from 60 to 97% between the equilibrium limit methods used in the analyzes. Finally, the cohesion and the friction angle value obtained at the instant of failure in the deterministic back analysis for black silt clay was cu=47.1 kPa and ϕu=0º. In the probabilistic back analysis the cohesion and the friction angle value obtained at the instant of failure was cu=33,8 kPa and ϕu=3,1º, with a probability of failure of 52,7%. With this, it is concluded that the Açu dam upstream slope failure occurred because of errors of strength parameters of the clay soil adopted in the design accompanied by the poor compaction and loss of the soil strength due to the excess of poropressures generated during the construction.

14
  • JOSÉ EDSON DE ALMEIDA JÚNIOR
  • EVALUATION OF SHORT-TERM RETREAT ON THE BARREIRA DO INFERNO COASTAL CLIFF USING TERRESTRIAL LASER SCANNING

  • Leader : VENERANDO EUSTAQUIO AMARO
  • MEMBRES DE LA BANQUE :
  • VENERANDO EUSTAQUIO AMARO
  • ADA CRISTINA SCUDELARI
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • ANDRE LUIS SILVA DOS SANTOS
  • Data: 18 août 2017


  • Afficher le Résumé
  • This research aims a short-term multi-temporal evaluation of the retreat in a sea-cliff of the Barreiras Formation, in the Barreira do Inferno Launch Center (CLBI, in Portuguese) located in the eastern coast of Rio Grande do Norte (RN), Brazil. The studies were conducted between August 2016 and February 2017 through a Terrestrial Laser Scanning (TLS), which is an equipment that utilizes a pulsed laser to map sea-cliffs. The first phase of the study used the point cloud generated on August 21, 2016, for the construction of 10 Digital Elevation Model (DEM) via four different software for selecting the interpolation method that best represents the studied surface. The second phase was the classification of the sea-cliff according to its main erosive cause through 30 transversal sea-cliff face profiles obtained through the DEM generated in the previous phase. It led to a subdivision of the sea-cliff in 5 segments according to its classification. The evaluation and quantification of the net erosion and the retreat rate were conducted through comparing the DEMs with the transversal profiles generated. The results expressed that the sea-cliff had a retreat of approximately 6 centimeters with a net erosion of 333 m³ during the study period. It was also observed the importance of evaluating the reliability of the point cloud because of the presence of blanks due to the shading during the data collection, which may cause significant errors. The evaluation of this sea-cliff was relevant not only because it was the first to be done through TLS in this type of formation, but also because it represents a new way for understanding the coast dynamic.

15
  • LUCY KHEYLER MACIEL DE MENDONÇA
  • Impacts of the application of law no. 27/2000 on real estate production in the neighborhood of Ponta Negra - Natal / RN.

  • Leader : LUCIANA DE FIGUEIREDO LOPES LUCENA
  • MEMBRES DE LA BANQUE :
  • LUCIANA DE FIGUEIREDO LOPES LUCENA
  • LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • REYMARD SAVIO SAMPAIO DE MELO
  • JOSYANNE PINTO GIESTA
  • Data: 22 août 2017


  • Afficher le Résumé
  • The Master Plan is the main document, in accordance with the Brazilian Constitution of 1988, which guides the development and planning policy of the urban expansion of a Municipality. Since successive modifications and revisions of the plan affect a real estate production capacity, as well as a dynamic of appreciation and the differentiated growth of some areas of the city to the detriment of others. In Natal, the use and occupation of the ground, is submitted to the capacity of urban infrastructure installed in the locality. In this regard, the approval of Law No. 27, on November 3, 2000, modified the urbanistic prescriptions for a part of Ponta Negra, implying the transformation of a large area, linked to this greater capacity of urban densification due to the expansion of Sanitary sewage network, considered at the time a deficit infrastructure. This study aims to analyze the impacts of the application of law on real estate production in Ponta Negra, which is different when compared to another neighborhood. For this purpose, a collection of information was carried out on all real estate development approved and registered in notary offices, as well as characteristics of the population, housing and infrastructure of Ponta Negra. The results show that the urban expansion was not decisive for the rate of civil construction, since more than half of the real estate developments are located out of the properly zone. The natural scenery of Ponta Negra for tourism, linked with infrastructure works aimed at the development of this activity, attracts external investments to the real estate market, implying in a large production and appreciation of real estate in a short time, excessive verticalization, market focused mainly for foreigners interested in second residences and, consequently, modification of the landscape.

16
  • ÍTALO VALE MONTE JÚNIOR
  • INFLUENCE OF THE RECYCLED CONCRETE AGGREGATE IN THE MECHANICAL BEHAVIOR OF MIXED MORTARS FOR COATING USE

     

  • Leader : MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • MEMBRES DE LA BANQUE :
  • ANA CECILIA VIEIRA DA NOBREGA
  • KLEBER CAVALCANTI CABRAL
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • Data: 25 août 2017


  • Afficher le Résumé
  • The construction activity promotes a large environmental liability due to the high consumption of non-renewable natural resources and energy, as well as generating large volumes of solid waste that are often inadequately destined. Thus, the use of solid construction and demolition wastes as a recycled aggregate becomes a viable alternative to mitigate the impact of construction on the environment. The recycled concrete aggregate (RCA), especially the coarse fraction (RCAC) with a diameter greater than 4 mm, presents superior quality to the mixed recycled aggregates, and can be used in the production of new concretes. On the other hand, the fine fraction (RCAF) with particles smaller than 4 mm contains a higher content of mortar adhered to the grain of RCA and presents inferior quality to the RCAC, restricting its use in new concretes and / or mortars. Thus, the objective of this research is to evaluate the behavior of mortars for coating with the substitution of natural aggregate (NA) for concrete residue (RCAF). From an experimental design, the lime / cement ratio (from 0.3 to 1.7) and the substitution of NA by RCAF (from 15 to 85%) were evaluated in the production of 14 mortars, 9 of them with RCAF and 5 of reference, standardizing the grain size profile of the NA and RCAF, the binder / aggregate ratio in 1: 3 and the consistency index in 260 mm. The physical, chemical, mineralogical and microstructural characteristics of the aggregates were evaluated by analysis of the unit mass, specific mass, laser granulometry, BET, FRX, DRX and MEV, as well as Los Angeles Abrasion, mortar content, water absorption and Pozzolanic activity for RCAF. Then, the mortar properties in the anhydrous, fresh and hardened states were evaluated through the granulometry tests by sieving, bulk density, consistency, weight variation, water absorption by capillarity and immersion, flexural tensile and compressive strenght, dynamic modulus of elasticity, adhesion strength and susceptibility cracking. It was found that the average values of mortar (31%), Los Angeles (30%), water absorption (15%) and density (1.09 g / cm3) in the ARCF were similar Literature. In the mortars, a reduction of mass density occurred with the increase of the RCAF, which also contributed to the increase of tensile strengths in flexion, compression and modulus of elasticity. No cracks were observed at 56 days of cure, in ARCF mortars, the adhesion strength obtained minimum acceptable values (0.3 MPa) for coating, but did not present statistical significance at 95% confidence.

17
  • JOÃO PAULO DA SILVA COSTA
  • Uplift behaviour of helical piles in sand subjected to static and quasi-static cyclic loading.

  • Leader : YURI DANIEL JATOBA COSTA
  • MEMBRES DE LA BANQUE :
  • YURI DANIEL JATOBA COSTA
  • CARINA MAIA LINS COSTA
  • CRISTINA DE HOLLANDA CAVALCANTI TSUHA
  • Data: 28 août 2017


  • Afficher le Résumé
  • Helical piles are foundation systems used for supporting compression, tension, and lateral loads. Advantages of helical piles over other foundation systems include fast installation and possibility to apply load immediately. Despite the significant growth around the world in the last 25 years, studies on the behavior of helical piles remain scarce. Field test results in pure sand deposits are particularly needed. In order to fulfil this demand, a field testing program involving helical piles subjected to vertical uplift loads has been conceived. A full-scale prototype of a helical pile with three bearing plates has been designed and built. Seven axial pull out tests with cyclic loading have been performed in a pure sand deposit. Five tests were carried out with static cyclic loading, and included up to 15 load-unload cycles. The other two tests were conducted with quasi-static cyclic loading. The results of the static load tests revealed that soil-pile system stiffness increases after completion of each static loading cycle. Theoretical and empirical methods were used to predict pile ultimate uplift static capacity, and gave conservative predictions as compared to the experimental field test results. The tests with quasi-static loading were carried out with distinct mean cyclic loads and load amplitudes. The results of these tests revealed that increasing mean cyclic load and load amplitude tend to reduce pile stability and soil-pile system stiffness. Soil-pile system static capacity was found to improve after application of quasi-static cyclic loads. Numerical models using the finite element method were developed to evaluate how the behavior of a pile under static loading and embedded in a sandy soil profile is affected by variations in important design parameters, such as helical plate diameter, spacing between helices, and depth of installation. Parametric analysis results gave insight into the distribution of stresses and strains in the soil mass around the pile, and into soil-pile failure mechanisms. According to the investigated conditions, optimum geometrical design parameters for a helical pile include 300 mm diameter plates, depth to diameter ratio of the shallowest helix equal to four, and inter-helix spacing equal to three helix diameters.

18
  • RICARDO CARLOS CARVALHO
  • Geological characterization and evaluation of the erodibility of the Barreira do Inferno Launch Center

  • Leader : MARIA DEL PILAR DURANTE INGUNZA
  • MEMBRES DE LA BANQUE :
  • MARIA DEL PILAR DURANTE INGUNZA
  • OSVALDO DE FREITAS NETO
  • VENERANDO EUSTAQUIO AMARO
  • RICARDO NASCIMENTO FLORES SEVERO
  • Data: 29 août 2017


  • Afficher le Résumé
  • The production of geological, geomorphological and geotechnical data on a given region, based on the characteristics of the physical environment, has a relevant role for the rational use of the soil, which can help to preserve the ecosystem and to develop more efficient urban works. The absence or incompleteness of these parameters can lead to soil loss due to lack of conservation activities or poor use of the surface horizons. In Brazil, the coastal zones have significant economic importance, since the Brazilian coast has a great concentration of population and a high tourist importance, and it is home to several state capitals. They are regions with unique combinations of so-called coastal ecosystems, which encompass the continent, beaches, ocean, riverbanks, dunes and mangroves and constantly suffer the effects of meteorological and hydrodynamic forces, resulting in areas highly vulnerable to morphological change and erosive processes, and these phenomena are one of the main factors that cause degradation and deterioration of environmental quality. The objective of this work was to identify, map and interpret geoenvironmental units (Altitude, Declivity, Geology, Geomorphology, Soils, Vegetation and Usage and Coverage) in the Launch Center of the Barreira do Inferno, an unit institutionally protected by the Brazilian Air Force, located  between densely occupied areas, where there is great anthropic influence. From the cartographic products generated in GIS environment and using geoprocessing, the various potentialities of erosion were analyzed together through map algebra, enabling the production of the Erosion Susceptibility Chart of the area in a scale of 1: 35,000.

19
  • TULIO CESAR DE SOUZA COSTA
  • Preliminary analisys upon spatial distribution of private real estate production in the city of Natal/RN between 1990 and 2015

  • Leader : LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • MEMBRES DE LA BANQUE :
  • LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • MARIA DE FATIMA ALVES DE MATOS
  • VENERANDO EUSTAQUIO AMARO
  • JOZILENE DE SOUZA
  • Data: 6 sept. 2017


  • Afficher le Résumé
  • In the past decades, real estate involvement in the occupancy process of urban space has been growing. This phenomenon emerges from both the demographic growth and economic changes Brazil went through in the past 30 years. Such facts, combined with a lack of accurate geographic information about the local real state, create obstacles on strategic decision making for the city, by both public administration and private enterprise. In front of this perspective, searching for new alternatives and technologies that aim to facilitate processing current data is necessary for optimizing real state analysis in Natal/RN. Therefore, this study aims making a first approach on spatial distribution of developments from 1990 up to 2015 found in real estate registry offices in Natal/RN, using tools based on Geographic Information System. For so, it was necessary georeferencing all developments registered in the period through an existing database. Using such methodology confirmed an increase on verticalization during the period, especially in the south and east zones, as well as a concentration of small units in peripheral areas. The municipality’s southern zone stands out for its intense housing production, confirming a need for expanding urban infrastructure and services. Finally, using georeferencing tools proved to be a valuable tool for the analysis of the spatialization of real estate development. 

20
  • IVANILDO SOARES DA SILVA
  • ENGINEERING IN THE RESTORATION WAYS: CONSTRUCTIVE SYSTEM AS AN INSTRUMENT OF ANALYSIS OF THE HISTORIC BUILDING IN RIO GRANDE DO NORTE.

  • Leader : MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • MEMBRES DE LA BANQUE :
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • JOSE CLEWTON DO NASCIMENTO
  • LUANA HONORIO CRUZ
  • NATALIA MIRANDA VIEIRA DE ARAUJO
  • Data: 25 sept. 2017


  • Afficher le Résumé
  • The purpose of the Restoration is to preserve the cultural property of historic building. The interventions in historic buildings for their conservation are guided by a specific methodology whose objective is the maintenance of the historical, artistic and cultural values attributed to these buildings, and these interventions are characterized as a cultural action. This action therefore requires a multidisciplinary team and when it comes to historic buildings, it is necessary the presence of a civil engineer in the team. These buildings are characterized by the use of ancient technologies and by a complex production process because it involves several factors that interact with each other as a system, a Construction System therefore. It is assumed that the knowledge of the Constructive System of each building contributes to the achievement of the principles of minimal intervention, reversibility and compatibility of materials and techniques in Restoration. The purpose of this descriptive research was to analyze how the Constructive System category contributes to the Restoration methodology, in the step of historic research of historic buildings in Rio Grande do Norte. A bibliographical research covering conservation theories, historical studies of the production process of buildings and systems theory was thus carried out. In addition, a documentary research and a field trip to get to know and to characterize the historic buildings in Rio Grande do Norte was also carried out. It was verified that the Constructive System allows to understand the process of production of a building, identifying factors that influence in the final form of this object and that they are characteristic of each time and place

21
  • RÍSIA AMARAL ARAÚJO
  • Não consta.

  • Leader : ANDREZA KELLY COSTA NOBREGA
  • MEMBRES DE LA BANQUE :
  • ANDREZA KELLY COSTA NOBREGA
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • ERICA NATASCHE DE MEDEIROS GURGEL PINTO
  • KLEBER CAVALCANTI CABRAL
  • Data: 6 nov. 2017


  • Afficher le Résumé
  • Não consta.

22
  • VICTOR PINHEIRO DA COSTA
  • Characterization of sterile residue from granitic pegmatitic deposits granulometrically reduced for application to earthworks.

  • Leader : FAGNER ALEXANDRE NUNES DE FRANCA
  • MEMBRES DE LA BANQUE :
  • FAGNER ALEXANDRE NUNES DE FRANCA
  • MARIA DEL PILAR DURANTE INGUNZA
  • OSVALDO DE FREITAS NETO
  • ALEXANDRE DA COSTA PEREIRA
  • Data: 30 nov. 2017


  • Afficher le Résumé
  • Mining activity as any process of extraction of natural resources
    causes impacts to the environment, whether in regard to changes in
    natural areas through their exploitation or in the generation of waste
    arising mainly from their mining and processing. Assuming that mineral
    resources are exhaustible and that the construction industry is
    responsible for the consumption of up to 50% of all mineral resources
    exploited on the planet, it is imperative to develop techniques for the
    reuse of mining waste in construction for that the use of natural goods
    and the accumulation of waste occur, thus minimizing the impacts
    caused to the environment. In this work, a proposal is proposed for
    adequate disposal of the residues from the pegmatitic feldspar of the
    Parelhas / RN region by means of their inclusion in geotechnical
    works. For this, the sterile pegmatitic feldspar (REFP) was subjected
    to a granulometric treatment process, obtaining a material with 100%
    passing through the sieve n ° 4 (4.8 mm). Subsequently, it was
    submitted to physical, chemical, mineralogical and mechanical
    characterization tests. Before the results were characterized as non-
    plastic and well graded silt sand with a solids specific mass of 2.66 g /
    cm3 and non-uniform granulometry. The results of X-ray diffraction
    showed a high percentage of silica (64.13%) and aluminum (15.08%),
    with a low content of total alkalis (10.62%) and a high oxide content of
    iron (5.25%) in relation to the chemical requirements for its
    consumption in the ceramic and glass industries. It was designated as
    an A-2- 4 material by the TRB (Transportation Research Board), which

    has excellent penetration support capability and can be used when
    compressed under modified energy under optimal conditions (pdmáx e
    wót), as a base element in pavements with N &lt;5.106. However, a loss
    of 50% of its penetration support capacity (ISC) was observed for
    moisture content equal to wót ± 1, revealing the need for a rigorous
    control when applied to pavements. As for the direct shear tests, the
    non-flooded samples showed cohesion values and friction angle at
    peak voltages ranging from 15 to 8 kPa and 53 to 43 degrees
    respectively for the normal, intermediate and modified compaction
    energies and overloads of up to 200 kPa. The flood did not cause
    measurable changes in the values of the peak voltages, however, it
    resulted in lower residual voltages. The REFP was presented as a
    material of low compressibility, not demonstrating expandable or
    collapsible behavior when flooded to the stress levels applied in this
    research. The results shown by the variable load permeability tests for
    samples molded under optimum conditions in the normal, intermediate
    and modified compaction energies, demonstrate that the residue is
    medium permeable (1,56 − 1,28 cm/s2). REFP presented 83% of
    pozzolanic activity, a result that can be satisfactory in mortars,
    concretes, soil-cement and improved soils. Technically, the residue
    presented properties that satisfy its use in earthworks and / or mixtures
    with binder elements, however, further studies are necessary to
    evaluate the energy cost required for its granulometric processing and
    the influence areas of its location to validate its applicability in these
    segments.

2016
Thèses
1
  • SILVIA CRISTINA JUSTO FERNANDES NOBRE DE ARAUJO
  • Análise de microestrutura e de características geotécnicas de misturas de Resíduo de Polimento de Porcelanato e solo.

  • Leader : CARINA MAIA LINS COSTA
  • MEMBRES DE LA BANQUE :
  • CARINA MAIA LINS COSTA
  • YURI DANIEL JATOBA COSTA
  • EDER CARLOS GUEDES DOS SANTOS
  • Data: 4 mars 2016


  • Afficher le Résumé
  • O Brasil é um país em desenvolvimento dotado de imensa quantidade de recursos naturais que necessitam ser preservados a fim de que o crescimento econômico seja associado ao desenvolvimento sustentável. A gestão de resíduos sólidos é um desafio contínuo para as indústrias no Brasil, incluindo as que produzem materiais cerâmicos. Neste trabalho, foi estudada a utilização de Resíduo de Polimento de Porcelanato (RPP) para a execução de aterros compactados. O RPP é um resíduo em consistência de lama gerado durante a etapa de polimento do material cerâmico porcelanato, composto por material pulverulento desprendido da peça cerâmica polida, por material abrasivo gasto e por água de resfriamento e lavagem. O RPP utilizado nesta pesquisa foi coletado em empresa localizada no município de Conde/PB e será estudado em misturas com solo areno-argiloso, para a execução de aterros. Foram realizados ensaios de caracterização e de resistência mecânica com o solo puro, o RPP puro e misturas de solo e resíduo nas proporções de 5%, 10%, 15% e 20% da adição de RPP em massa seca de solo. Os ensaios de caracterização realizados em todas as amostras foram: massa específica dos sólidos, granulometria conjunta, granulometria a laser, limites de Atterberg, fluorescência de raios X, difração de raios X, microscopia eletrônica de varredura e compactação. As amostras também foram compactadas e submetidas ainda a ensaios de cisalhamento direto e provas de carga em placa. Este último ensaio foi realizado em placa circular de 30 cm de diâmetro, sobre amostra moldada em caixa metálica no laboratório de Mecânica dos Solos da UFRN. A capacidade de carga do aterro foi avaliada para as amostras compactadas de solo puro e da mistura de 5, previamente selecionada. Todos os ensaios de resistência mecânica foram desenvolvidos na condição inundada, a fim de minimizar possíveis influências de sucção matricial. Os resultados dos ensaios de caracterização apontam que o RPP é um material fino, com granulometria inferior a 0,015 mm, rico em sílica e alumina, com partículas de formato angular. O solo em estudo é uma areia argilosa, caracterizado como laterítico, com altos teores de alumina e óxido de ferro, e com partículas de formato arredondado. Tanto o solo puro quanto as misturas foram identificados como materiais fracamente plásticos, enquanto o resíduo se mostrou medianamente plástico. Os resultados dos ensaios de cisalhamento direto apontam que a adição de resíduo no solo não provocou variações significativas nos valores de ângulo de atrito interno das misturas, em relação ao solo puro, mas, no que diz respeito aos valores de pico da resistência ao cisalhamento, ocorreu uma tendência a um decréscimo na resistência das misturas com o aumento da quantidade de resíduo adicionada. Tanto o solo puro quanto a mistura de 5% apresentaram ruptura por puncionamento, para a prova de carga em placa. O resultado da prova de carga em placa mostrou também que a mistura de 5% apresentou tensão admissível 44% maior do que o solo puro. Os recalques da Mistura de 5% também foram menores do que os do solo puro.

2
  • JOÃO PAULO DE BARROS CAVALCANTE
  • Contribuição ao estudo de treliças não lineares considerando efeitos térmicos

  • Leader : DANIEL NELSON MACIEL
  • MEMBRES DE LA BANQUE :
  • DANIEL NELSON MACIEL
  • ADA CRISTINA SCUDELARI
  • JOÃO CARLOS ARANTES COSTA JÚNIOR
  • MARCELO GRECO
  • Data: 11 mars 2016


  • Afficher le Résumé
  • O presente trabalho consiste na análise numérica via Método dos Elementos Finitos (MEF) de treliças submetidas a carregamentos térmicos, mecânicos e suas respectivas interações. A metodologia proposta baseia-se no teorema da mínima energia potencial, escrita em relação as posições nodais ao invés dos deslocamentos para lidar com problemas termomecânicos, levando-se em consideração os efeitos das não linearidades física e geométrica. Referente aos problemas dinâmicos, a solução da equação de equilíbrio é alcançada através da discretização temporal perante diferentes algoritmos de integração temporal, explícitos e implícitos. A formulação é estendida para problemas de impacto entre treliças e anteparo rígido, onde as posições nodais são restringidas através da condição de penetração nula. Sendo assim, apresenta-se uma formulação termodinamicamente consistente, fundamentada na primeira e segunda lei da termodinâmica e na energia livre de Helmholtz, para analisar problemas dinâmicos de estruturas treliçadas com comportamento termoelástico e termoplástico. A implementação dos problemas consiste no desenvolvimento de rotinas computacionais, sendo os resultados numéricos da formulação proposta confrontados com exemplos encontrados na literatura especializada.

3
  • THIAGO DE SOUZA LOUZADA
  • Emprego de Geossintéticos na Construção de Telhados Verdes: Análise da Capacidade de Retenção de Água


  • Leader : FAGNER ALEXANDRE NUNES DE FRANCA
  • MEMBRES DE LA BANQUE :
  • FAGNER ALEXANDRE NUNES DE FRANCA
  • ADA CRISTINA SCUDELARI
  • HELIO RODRIGUES DOS SANTOS
  • GREGÓRIO LUÍS SILVA ARAÚJO
  • Data: 18 mars 2016


  • Afficher le Résumé
  • Considerando a situação ambiental atual das grandes cidades, bem como a impermeabilização do solo, o que acaba por diminuir a capacidade de infiltração da água, este trabalho apresenta o telhado verde como alternativa viável e compensatória no controle do escoamento superficial urbano. Os telhados vivos, coberturas vegetadas ou ecotelhados como também são chamados, além de contribuírem no controle do escoamento superficial urbano, proporcionam vantagens, como a diminuição de ilhas de calor em centros urbanos, bom isolamento térmico em climas frios e quentes, melhora da qualidade do ar e outros. As coberturas verdes são relativamente populares na Europa, especialmente na Alemanha, país onde há uma ampla e crescente utilização do sistema. Os geossintéticos mostram-se importantes para o avanço da técnica, podem ser utilizados com diferentes funções, como na impermeabilização da base, na proteção contra raízes, como filtro, na drenagem, no armazenamento de água e na estabilidade do substrato. Como objetivo geral desta pesquisa, buscou-se a partir de modelos físicos experimentais e um simulador de chuvas, observar a capacidade de retenção de água para diferentes configurações de telhados verdes. As variações foram no material geossintético utilizado como camada drenante e na inclinação dos módulos. Aspectos construtivos e de funcionamento dos módulos também foram observados. Como resultados, comprovou-se que os telhados verdes mesmo que com 4 cm de altura de substrato, conseguem reter considerável quantidade de água, que somado ao atraso no inicio do escoamento, os torna uma medida compensatória nos sistemas de drenagem urbana. A capacidade de retenção, do módulo que teve uma geomanta como camada drenante ficou entre 47% quando inclinado e 65% quando plano. Essa retenção foi obtida para intensidades de precipitação de 44 mm/h e 42 mm/h respectivamente, para simulações de 20 minutos. Para este mesmo módulo, o atraso no inicio de escoamento foi de 9 minutos quando inclinado e 15 minutos quando plano, comprovando que a inclinação da cobertura verde influencia na capacidade de retenção e no tempo de inicio de escoamento. O módulo em que apenas um geotêxtil separava o substrato da camada de impermeabilização apresentou uma excelente capacidade de retenção de água, mas a capacidade de drenagem foi insuficiente, ou seja, a intensidade de precipitação foi superior a vazão apresentada pelo sistema, levando-o a transbordar. No módulo com a geomanta como camada drenante o sistema funcionou perfeitamente, não apresentando transbordamento em nenhuma ocasião. Quanto à utilização dos geossintéticos, eles possibilitaram a montagem dos módulos sem maiores problemas, de forma simples e rápida, bastando apenas algumas horas para fixar os materiais e plantar a vegetação.

4
  • CHARLES PEREIRA CHAVES
  • DESENVOLVIMENTO DE MODELOS FÍSICOS REDUZIDOS PARA AVALIAÇÃO DE FUNDAÇÕES POR ESTACAS HELICOIDAIS EM SOLOS REFORÇADOS COM GEOSSINTÉTICOS.

  • Leader : FAGNER ALEXANDRE NUNES DE FRANCA
  • MEMBRES DE LA BANQUE :
  • FAGNER ALEXANDRE NUNES DE FRANCA
  • YURI DANIEL JATOBA COSTA
  • LEONARDO FLAMARION MARQUES CHAVES
  • GREGÓRIO LUÍS SILVA ARAÚJO
  • Data: 21 mars 2016


  • Afficher le Résumé
  • DESENVOLVIMENTO DE MODELOS FÍSICOS REDUZIDOS PARA AVALIAÇÃO DE FUNDAÇÕES POR ESTACAS HELICOIDAIS EM SOLOS REFORÇADOS COM GEOSSINTÉTICOS.

5
  • CLEBER MEDEIROS DE LUCENA
  • Avaliação da eficiência de uma câmara de carbonatação projetada e montada em laboratório.

  • Leader : MARCOS ALYSSANDRO SOARES DOS ANJOS
  • MEMBRES DE LA BANQUE :
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • JOSE NERES DA SILVA FILHO
  • NORMANDO PERAZZO BARBOSA
  • Data: 5 mai 2016


  • Afficher le Résumé
  • Esta pesquisa foi pautada no projeto e construção de uma câmara de carbonatação acelerada, em quatro etapas distintas, capaz de equipar um laboratório destinado a estudar a durabilidade das edificações, principalmente no tocante às pesquisas relacionadas às análises de materiais cimentícios. A primeira etapa foi determinada no projeto propriamente dito, onde se pensou em dimensões e materiais a ser utilizado. A segunda etapa destinou-se a construção da câmara de carbonatação e finalizou com o teste de estanqueidade com o intuito de garantir sua vedação. A pesquisa teve continuidade em sua terceira etapa, com a automação e microcontrole da câmara de carbonatação através de um algoritmo desenvolvido e programado, capaz de interagir com a programação presente nos sensores e válvulas adquiridos comercialmente. Esta etapa, ainda contou com a calibração do sensor, utilizando padrões rastreáveis internacionalmente e a realização de pré-testes em modelo reduzido, antes da instalação definitiva na câmara de carbonatação. A quarta etapa foi submeter ao ensaio de carbonatação acelerada, amostras cilíndricas de concreto com dimensões de 100mm x 200mm, no interior da câmara de carbonatação acelerada, conforme os padrões da Laboratório Nacional de Engenharia Civil – LNEC  E-391 (1993) e especificação FINAL DRAFT FprCEN/TS 12390-12, da European Committee Standardization de novembro de 2010. As amostras foram submetidas ao ensaio de carbonatação acelerada aos 7, 14, 28, 42 e 56 dias de exposição e obtiveram respectivamente, profundidades médias de carbonatação de 0,00mm, 1,62mm, 2,65mm, 3,35mm e 3,72mm. Por fim, a pesquisa cumpriu seus objetivos em projetar e construir uma câmara de carbonatação acelerada em laboratório, bem como teve sua eficiência avaliada através da calibração de seus dispositivos avaliadores de CO2 e sua estanqueidade, e garantiu sua funcionalidade através do ensaio de carbonatação acelerada em um concreto convencional com 365kg/m³ de cimento.

6
  • FERNANDA KAROLLINE DE MEDEIROS
  • Estudo de concretos autoadensáveis com reduzidos teores de cimento e elevados teores de adições minerais

  • Leader : MARCOS ALYSSANDRO SOARES DOS ANJOS
  • MEMBRES DE LA BANQUE :
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • ANDREZA KELLY COSTA NOBREGA
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • NORMANDO PERAZZO BARBOSA
  • Data: 6 mai 2016


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  • O processo de produção de concreto gera um significativo impacto ambiental por ser um dos maiores consumidores de matéria-prima, como areia, pedra, cascalho moído e água. Entretanto, o maior impacto é causado pela produção do cimento Portland, material indispensável ao concreto. Materiais como a cinza do bagaço da cana-de-açúcar, sílica da casca de arroz, metacaulim e sílica ativa, são adições minerais que desempenham importante papel nas propriedades de resistência e de durabilidade, quando utilizados em mistura com cimento Portland e, sob certas condições, podem perfeitamente substituir altos teores cimento nas misturas, conferido a elas, além dos benefícios conhecidos que a redução de cimento acarreta, aumento significativo de durabilidade. A utilização de concreto autoadensável (CAA) tem crescido significativamente por suas características de alta fluidez e coesão e pela possibilidade de moldagem in loco sem vibração, formando um produto livre de vazios e falhas e que apresenta também, capacidade de fluxo através do seu peso próprio preenchendo completamente as fôrmas e atingindo a compactação mesmo em estruturas densamente armadas. Frente ao exposto, este trabalho se propôs avaliar as propriedades reológicas, físicas, mecânicas e de durabilidade dos eco-concretos autoadensáveis com a incorporação de altos teores de cinza da biomassa da cana-de-açúcar, sílica da casca de arroz e metacaulim. Para isso, foram analisados concretos com incorporação de 40% e 50% e um concreto autoadensável com materiais convencionais sem adições minerais para utilização como referência. Os resultados evidenciaram que a sinergia resultante das misturas desenvolvidas revelou desempenhos mecânicos e de durabilidade superiores ao CAA de referência, concluindo-se então que é possível produzir concretos autoadensáveis com desempenhos promissores e com redução significativa do consumo de cimento para níveis de cerca 220 kg / m3, contribuindo assim para a sustentabilidade da indústria da construção, minimizando energia liberada e a compactação.

7
  • EMANUEL ERIVAN SILVA DA CUNHA
  • CORRELATIONS BETWEEN SPT AND CPT TEST RESULTS FOR A SEDMIENTARY SANDY SOIL 

  • Leader : YURI DANIEL JATOBA COSTA
  • MEMBRES DE LA BANQUE :
  • YURI DANIEL JATOBA COSTA
  • CARINA MAIA LINS COSTA
  • JOHN ELOI BEZERRA
  • NELSON AOKI
  • Data: 30 mai 2016


  • Afficher le Résumé
  • The standard penetration test (SPT) is the most commonly used in situ test for obtaining the required geotechnical parameters for foundation analysis and design in Brazil. Since in most situations only SPT data is available, the search for new SPT-CPT correlations is necessary. However, most of the available SPT-CPT correlations in Brazil have been established for soils of southern regions of the country. New local correlations for other soil types are therefore necessary. This study aims at determining correlations between the SPT resistance number (NSPT), and the CPT tip resistance (qc) and sleeve friction resistance (fs) for a silty sand deposit at the city of Natal, at the Northeast coast of Brazil. Using linear fittings and a simplified geostatistic approach, correlations were obtained for 88 SPT boreholes and eight CPT boreholes. The NSPT blowcount values where corrected for the energy of 60%. SPT-CPT correlations were devised using the following approaches: variogram analysis, inverse distance weighting (IDW) and ordinary kriging. 

8
  • ELTON CORTÊS ROCHA SIQUEIRA FILHO
  • A Difusão de Inovações Tecnológicas como Estratégia da Oferta do Mercado da Construção Civil em Natal/RN

  • Leader : LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • MEMBRES DE LA BANQUE :
  • LUIZ ALESSANDRO PINHEIRO DA CAMARA DE QUEIROZ
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • JOZILENE DE SOUZA
  • Data: 3 juin 2016


  • Afficher le Résumé
  • Na atualidade as inovações tecnológicas devem ser vistas como uma estratégia competitiva das organizações no setor da construção civil. A difusão de novas tecnologias neste setor é muito similar ao aplicado em aos demais setores industriais, porém, no caso da construção civil, ainda se verifica certo grau de resistência das partes envolvidas. Desde os projetistas, passando pelos administradores e chegando até os trabalhadores, persiste uma relativa resistência à inovação tanto no que diz respeito às técnicas construtivas quanto na introdução de novos materiais, pois as incertezas do sucesso os tornam receosos. Discutiremos alguns aspectos associados à adoção de inovações tecnológicas no setor da construção civil como estratégia do Mercado imobiliário. A problemática desta pesquisa concentra-se em ampliar a compreensão do uso das inovações tecnológicas na produção imobiliária como um reflexo das mudanças nos sistemas construtivos e materiais. Partindo do caso empírico e utilizando a base estabelecida pretende-se testar a hipótese de que o processo de introdução de inovações tecnológicas no mercado da construção segue a lógica de valorização dos empreendimentos imobiliários privilegiando os empreendimentos de alto padrão e localizados nos bairros mais valorizados, com a adoção de materiais e processos construtivos mais atuais e eficientes. Pretende-se estudar então a evolução no uso de inovações tecnológicas relacionadas com os processos construtivos enquanto diferencial nas estratégias utilizadas pelos promotores imobiliários no município de Natal entre 1990 e 2010.

9
  • FILIPE BRUNO DOS SANTOS SILVA
  • EVALUATION OF BLENDS OF PORCELAIN TILE POLISHING RESIDUE AND SOIL FOR USING IN ROAD EMBANKMENTS

  • Leader : CARINA MAIA LINS COSTA
  • MEMBRES DE LA BANQUE :
  • CARINA MAIA LINS COSTA
  • YURI DANIEL JATOBA COSTA
  • ALEXANDRE DA COSTA PEREIRA
  • JEFFERSON LINS DA SILVA
  • Data: 26 août 2016


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  • With the growing industrial advancement, solid waste management becomes a constant challenge in society. This scenario is also a fact in Brazilian industries, including those producing ceramic materials. The polishing step in the production of porcelain tiles in ceramic industries produces large amounts of a residue consisting of ceramics remains, water and traces of abrasive discs used in the polishing step. This residue consists in a white powder of fine grain and variable chemical composition, known as Porcelain Tile Polishing Residue (RPP). In this study, was researched the use of mixes of soil and RPP for use in road embankments. The residue used was collected in a company located in Conde / PB and was studied in mixtures with a sandy-clayey soil. In the present study, was used different dosages of residue, specifically, 0% (pure soil) 5%, 10%, 15%, 20% and 40% added in relation to the dry mass of soil. Besides the characterization of materials by conducting tests to determine Atterberg limits, grain size distribution and specific solid weight, soil compaction tests were carried out to determine the CBR (California bearing ratio) and oedometer consolidation tests.  A plate load test was conducted in the laboratory with the 10% blend, comparing to plate load tests data on specimens of pure soil and 5% blend obtained in the technical literature. In virtue of the chemistry of the material, a preliminary study was conducted on the influence of pozzolanic activity on results. Finally, there was an environmental character analysis, based on the chemical collection and analysis of solubilized extract obtained from a sample of pure residue. The mechanical tests performed were conducted under inundated conditions, willing to reduce the influence of soil suction. The evaluation of the soil and mixtures California Bearing Ratio was made using normal and modified proctor energy. The tests showed a reduction of the average resistance of the blends compared to the pure soil’s one. For the consolidation tests, it was observed that the blend with 5% added RPP had a smaller deformation than the specimen of pure soil in the same stress values, unlike the others mixtures which were more deformable. The results of the plate load test showed that the 10% blend has a lower bearing capacity than the pure soil and the 5% blend with bigger settlements for the same stress values. The effect of pozzolanic activity on the results was studied from tests with samples that stood drying for a time after flood, so that the reactions could occur. The results showed that the tests with drying period generally show a slight improvement on mechanical characteristics. With all the data obtained in this study, it can be said that, in general, the residue does not significantly change the mechanical behavior of soil to levels up to 10% addition. For values above that, there is a poorer mechanical performance, but depending on use, does not preclude its application, making all mixtures studied potential materials for execution of embankments in road works. The pure soil and 5% blend compressed in modified energy can also be used as sub-base material pavement layers. The other mixtures can be used as subgrade improvement layer, if their CBR value is higher than the subgrade in question. Regarding the environmental character of the research, it was observed that for the studied parameters, the concentrations are below the limits suggested by NBR 10004.

10
  • WESLEY FEU DOS SANTOS
  • TREATMENT OF INFLUENCE ON THERMAL PROPERTIES MECHANICAL AND CONCRETE MICROSTRUCTURE self-compacting CONTAINING ADDITION OF metakaolin and filer LIMESTONE.

  • Leader : MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • MEMBRES DE LA BANQUE :
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • ANDREZA KELLY COSTA NOBREGA
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • GIVANILDO ALVES DE AZEREDO
  • Data: 9 sept. 2016


  • Afficher le Résumé
  • The manufacture of Portland cement is an activity that causes great environmental impact due to its high CO2 emission rate in the atmosphere. In order to reduce this impact, technical feasibility of alternative materials to replace Portland cement has been increasingly analyzed. It is already known the benefits that mineral additions infers to conventional concrete (CV), however, little is known of their use in self-compacting concrete (SCC) subjected to heat treatment. This work evaluates the effects of the incorporation of limestone fillers (LP) and metakaolin (MK) in the hydration of self-compacting concrete, when subjected to thermal curing. For this purpose six SCC compositions were produced, as a reference without mineral addition, four binary mixtures with replacement of cement with 10% MK, 10% LP, 20% MK and 20% LP and a tertiary with substitution of cement by 10% MK and 10% LP. The concrete were measured and made the tests slump flow, T500, L-box, Vtest and J-ring to characterize the SCC fresh. After started the crystallization reactions (about 3 hours), range called pre-curing, the molded specimens were cured through total immersion in a warm bath. The heating rate used was 20 °C/hr, reaching the maximum temperatures 50, 60 and 70 °C, with subsequent cooling 10 °C/hr. The total cycle time (pre-curing, heating, cooling and isothermal level) was 18 to 20 hours. Also, specimens were prepared which were cured by immersion in water at room temperature. The analyzed properties in the hardened state of all compositions were compressive strength at ages of 1, 3, 7 and 28 days at modulus, water absorption by capillarity, density, and total absorption to 28 days of age. The analysis of the microstructure of different concrete was given by scanning electron microscopy and X-ray diffraction at 1 and 28 days of age. The CAA thermally cured obtained a high increase in compressive strength at 1 day old, when compared to CAA cured at room temperature. For each dosage analyzed, there is a maximum temperature within the thermal cycle, which provides better mechanical performance to the CAA. The thermal curing causes changes in the microstructure, including, promote the rapid formation of calcium silicate hydrate (CSH).

11
  • ALBA CESANNA COUTINHO ROCHA
  • TECHNOLOGY AND MANAGEMENT STRATEGIES FOR SUSTAINABLE CONSTRUCTION IN NATAL: PROJECTS AND EXECUTIONS 

  • Leader : LUCIANA DE FIGUEIREDO LOPES LUCENA
  • MEMBRES DE LA BANQUE :
  • LUCIANA DE FIGUEIREDO LOPES LUCENA
  • REYMARD SAVIO SAMPAIO DE MELO
  • CLAUDIA COUTINHO NÓBREGA
  • Data: 31 oct. 2016


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  • The construction sector has been consolidated as one of the most relevant in the Brazilian economy, partly due to the development of urban centers. One of the challenges of our country has been the inadequacy of the current construction requirements of sustainability. Currently, the sector is considered one of which cause most environmental impacts due to the high volume of extracted natural resources; the generation of solid waste and; the greenhouse gas level emitted into the atmosphere. In order to minimize the impacts caused by the construction, several studies have been undertaken to obtain technologies and practices associated with the management plan make the most sustainable buildings. This study aims to establish guidelines to contribute to the sustainable development of construction companies in the city of Natal/RN from the planning phase to the implementation of vertical residential developments. We conducted an exploratory study through the application of a questionnaire and the completion of a checklist on developments under construction. The evaluation of the results was performed with the help of SWOT analysis where the particularities of each company to the subsequent exchange of data were identified. Finally it was possible to draw up model improvements, aiming to use the strengths to seize opportunities (SO) and overcome the threats (ST), and minimize the weaknesses to take advantage of the opportunities (WO) and avoid possible threats (WT) in the local construction scene. The study showed that the industry culture and unskilled labor-work are not the only aggravating to achieve sustainable development have been identified in the companies the lack of investment in technical training, environmental planning, integration of alternative materials and the introduction of environmental measures that do not generate immediate profits. If the technological and managerial strategies are used properly and in line with the environmental quality processes in order to optimize the use of materials, minimize waste generation and ensure the quality of life for residents by reducing environmental impacts. Thus, it is possible to generate continuous improvements in the production process of enterprises, and collaborate with the sustainability of the construction industry.

12
  • DUÍLIO ASSUNÇÃO MARÇAL DE ARAÚJO
  • PLATE DIMENSION EFFECT ON PLATE LOAD TEST RESULTS IN SAND

  • Leader : CARINA MAIA LINS COSTA
  • MEMBRES DE LA BANQUE :
  • CARINA MAIA LINS COSTA
  • JOEL ARAUJO DO NASCIMENTO NETO
  • YURI DANIEL JATOBA COSTA
  • BERNADETE RAGONI DANZIGER
  • Data: 18 nov. 2016


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  • Plate load tests represent an important tool on foundation design because it allows to define allowable stresses and settlements. However, when carried out on sand, the extrapolation of the results from the model (plate) to the prototype (foundation) becomes more complex, as compared to tests on clay. This work aims at evaluating the plate dimension effect on the result of plate load tests in sand. The study included analyses field in the test results and numerical simulation. The plate load tests in the field were carried out in sand deposits, with relative densities of 45% and 70%. These tests were executed with quick maintained load using plates with 0.30, 0.50, 0.80 m in diameter. In an attempt to better evaluate the effect of the dimension of the plate, the numerical simulations were carried out with plate dimensions ranging from 0.15 to 3.0 m. The main goal of this phase of the research was to assess the effect of the plate dimension on the allowable stress and the corresponding settlement of the plate. The numerical simulation was performed by using the finite element software Plaxis 2D and the behavior of the soil was represented by the hyperbolic model Hardening Soil. Since a clear failure pattern was not possible to be identified with the stress-settlement curves, different “conventional” failure criteria were used to find the corresponding allowable stress. Distinct allowable stress values were obtained with the different methods. The plate dimension effect on the allowable stress was found to be dependent on the assumed failure criterion. Differently from what the theoretical methods predict, the allowable stress followed a non-linear increase with plate dimension. Lastly, the influence of the soil relative density on the plate soil results was assessed for different plate sizes. It has been found that the relative density plays a low influence on stresses and settlement variation with the plate diameter. tensões e recalques com o aumento da dimensão.

13
  • DANYEL FLÁVIO LOPES DE PAIVA
  • The influence of aggregate grafted in the mechanical resistance and properties of fracture of a concrete for rigid pavement.

  • Leader : MARCOS ALYSSANDRO SOARES DOS ANJOS
  • MEMBRES DE LA BANQUE :
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • ANA CECILIA VIEIRA DA NOBREGA
  • Data: 25 nov. 2016


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  • The number of paving works performed in Brazil in recent years has increased considerably, especially the works whose rigid flooring solution has been adopted. However, compared to countries like the United States - US and developed European countries, for example Germany, it appears that the number of paved highways in Brazil is still small, especially with regard to the percentage of highways paved with Portland cement concrete (rigid pavement) compared to the use of asphalt concrete (flexible pavement). The increasing use of Portland cement concrete as paving solution has led to the development of several studies looking improve enforcement techniques and the improvement in the choice of materials and features that may favor the durability of the pavement as a whole. Despite this reality, this study aims to analyze the influence of coarse aggregate on the mechanical strength and fracture properties of concrete for rigid flooring, used in duplication of work and adjustment capacity of the BR-101 / RN, Northeast corridor between the cities of Parnamirim / RN and Ares / RN. In the first analysis, it was varied coarse aggregate the content of the mark, where the percentage of coarse aggregate in terms of the total number of households was 59% to 69%. For the second analysis was the reference mark reproduced only with aggregate maximum diameter 12.5 mm, 19 mm and 25 mm. For both analyzes were made to axial compressive strength test, traction in flexion and diametrical compression, elastic modulus, fracture toughness and fracture energy. The analysis results of the effects of the contents showed that stroke with less content of coarse aggregate - T (59%) showed higher mechanical resistance with respect to the mark - REF (64%), with 8% increments for resistance to compression and tension in flexion, while its fracture toughness and fracture energy decreased by 7% and 12%, respectively. But the trace-added content - T (69%) had a decrease in the mechanical strength by 12% for compressive strength and traction in flexion, but increased fracture toughness and energy of 4% fracture and 2%, respectively . Since the results of analysis of influence of the maximum diameter of coarse aggregate showed that reducing the maximum aggregate diameter caused increased mechanical strength and decreased fracture parameters. The VAR trace. 12, showed increases compared to the reference line (REF) of 12% for the compressive strength and 19% for the tensile strength in bending, but with 38% reductions in fracture toughness and 22% for energy fracture. The greatest results of fracture parameters in this analysis were presented by the mark - REF, but with the difference to be insignificant in relation to the VAR trait. 25

14
  • THIAGO VIEIRA FONSECA
  • Evaluation of self-compacting concretes with low content of cement incorporating metakaolin, pozzolan of rice husk, limestone filler, and addition of hydrated lime.

  • Leader : MARCOS ALYSSANDRO SOARES DOS ANJOS
  • MEMBRES DE LA BANQUE :
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • ANA CECILIA VIEIRA DA NOBREGA
  • Data: 15 déc. 2016


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  • The concrete industry is a major consumer of natural resources from aggregate extraction to Portland cement production, when a large amount of limestone is extracted. In addition, the cement industry has great utility in greenhouse gas emissions. However, it is possible to reduce the environmental impact caused through the concrete industry by using waste from other industries as components of the fine materials, considerably reducing the consumption of cement and maintaining or improving the mechanical properties and durability. The self-compacting concrete (SCC) has a high content of fine materials and has been widely used due to its characteristics of high fluidity and cohesion. In this way, the present work investigated the feasibility of the development of SCC's made with high levels of mineral additions and hydrated lime. For this, cement was replaced in 60% by mineral additions (pozzolan of rice husk, metakaolin and limestone filler) based on the reference admixture with consumption of 451.1 kg/m³ of cement. So, new admixtures with cement consumption were originated between 167.7 kg/m³ and 173.3 kg/m³. The hydrated lime was incorporated as an addition in three admixtures in the content of 5% on the total mass of the fine materials. The SCC's were characterized in the fresh state by the slump flow test, T500, J-ring, V-funnel and L-box. In order to evaluate the mechanical performance of the SCC's, tests of compressive strength, ultrasonic pulse velocity and modulus of elasticity were carried out, and for the evaluation of the durability, capillary absorption, chloride ion diffusion, electrical resistivity and carbonation were analyzed. The SCC's with mineral additions presented satisfactory mechanical performance, although inferior to the reference admixture. The compressive strength at 28 days of the concretes with mineral additions showed a reduction of 15 to 60% in relation to the reference admixture, but all the results were compatible with structural concretes according to the requirements of NBR 6118 (ABNT, 2014). Regarding the durability, the concrete with mineral additions showed a reduction in the diffusion coefficient of chloride ions that varied 25.4% and 74.8%. The electrical resistivities of the reference concrete were much lower than those of concrete with mineral additions, but all the admixtures were classified as probable negligible corrosion rates. The electrical resistivities suffered great reduction when analyzed in carbonated samples. The analysis of the accelerated carbonation showed that the substitution of cement by mineral additions at high levels makes the SCC's very susceptible to carbonation. As for the addition of hydrated lime, it was verified that its effect was not positive in the mechanical performance of the SCC's studied, but it had a positive effect in reducing the carbonation depth.

15
  • MAURICEIA MEDEIROS
  • STUDY OF COATING MORTARS WITH WASTE SCHEELITE

  • Leader : ANDREZA KELLY COSTA NOBREGA
  • MEMBRES DE LA BANQUE :
  • ANDREZA KELLY COSTA NOBREGA
  • ENIO FERNANDES AMORIM
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • Data: 19 déc. 2016


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  • The state of Rio Grande do Norte has a large concentration of scheelite, the main source of tungsten, an important chemical element for production in various industries. When extracting the raw mineral material, tons of waste are generated and lunges in the environment. This work aims to analyze the use of this waste as a substitute for sand in the formulation of coating mortars, due to its favorable characteristics. Scheelite waste samples were collected in Brejuí mine, Currais Novos/RN, and after its initial characterization, it was observed the application of the thick residue in the mortars in study. Were analyzed mixing mortars by 1:1:6 and 1:3, both in volume with percentages of 0%, 25%, 50%, 75% and 100% of the sand replaced by scheelite thick waste. It was used Portland cement CP II-Z 32 and CH-I hydrated lime with ratio water/cement between 0.18 to 0.16 and a consistency of 260 ± 5mm. Subsequently, the mortars were analyzed in the fresh state through the consistency testing, bulk density, water retention and incorporated air content and in the hardened state by the compressive strength test and tensile strength in bending, bulk density, water absorption by immersion, water absorption by capillary and dynamic modulus of elasticity. The results showed a reasonable improvement in the properties of mechanical strength, dynamic modulus of elasticity and water retention of mortars produced with scheelite residue. However, some properties such as bulk density, water absorption by immersion and by capillarity presented results above what was found for reference mortars, causing heavier mortars, with less workability and more water absorption than reference mortars.

2015
Thèses
1
  • TAHYARA BARBALHO FONTOURA
  • COMPORTAMENTO TENSÃO - DEFORMAÇÃO E RESISTÊNCIA AO CISALHAMENTO DE UMA AREIA DE DUNA CIMENTADA ARTIFICIALMENTE

  • Leader : OLAVO FRANCISCO DOS SANTOS JUNIOR
  • MEMBRES DE LA BANQUE :
  • ANTONIO JOAQUIM PEREIRA VIANA DA FONSECA
  • MARIA DEL PILAR DURANTE INGUNZA
  • RICARDO NASCIMENTO FLORES SEVERO
  • ROBERTO COUTINHO
  • Data: 20 févr. 2015


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  • Nas últimas décadas vários trabalhos vêm sendo realizados no sentido de compreender o comportamento dos solos com cimentação (natural ou artificial) entre as partículas. As areias, objeto de estudo desse trabalho, geralmente apresentam boa capacidade de suporte. Entretanto, às vezes se faz necessária a realização de melhoramento do solo, para aumento da capacidade de suporte ou mesmo de se considerar o efeito da cimentação natural que ocorre em algumas areias. Para isso, é necessário que se compreenda o comportamento mecânico dos solos cimentados. O objetivo geral deste estudo foi descrever o comportamento tensão - deformação - resistência de uma areia originária de Dunas de Natal cimentada artificialmente através de ensaios de compressão simples e ensaios de compressão triaxial drenados. Foi avaliada a influência do teor de cimento, da umidade de moldagem, do índice de vazios e da tensão confinante sobre a resistência e verificada a validade do uso do fator vazios/cimento na estimativa da resistência à compressão simples, da resistência ao cisalhamento em condições drenadas e do comportamento tensão-deformação. As amostras dos ensaios de compressão simples foram moldadas com diferentes teores de umidade de moldagem (6%, 9% e 12%) e diferentes teores de cimento (2,5%; 5,0%; 7,5% e 10%). Nos ensaios de compressão triaxial, todas as amostras foram moldadas na umidade de 6%, com três índices de vazios (0,6; 0,7 e 0,8) e quatro teores de cimento (0,0%; 2,5%; 5,0% e 7,5%), sendo rompidas sob diferentes tensões confinantes (50, 100, 200 e 300 kPa).  O agente cimentante utilizado foi o Cimento Portland de Alta resistência inicial resistente aos sulfatos (CP-V ARI – RS). Concluiu-se que, a resistência a compressão simples cresce com o aumento do teor de cimento e com a diminuição da umidade de moldagem. Quanto a resistência ao cisalhamento, verificou-se que esta aumenta com o aumento da quantidade de cimento e com a diminuição do índice de vazios. Percebeu-se ainda que a variação nos valores de ângulo de atrito não se mostrou tão significativa quanto a variação da coesão. Por fim, foi verificado que o fator vazios/cimento mostrou-se ser um parâmetro muito eficaz e confiável na previsão do comportamento da areia de Natal para dosagem de solo-cimento.

2
  • ANDRE AUGUSTO NOBREGA DANTAS
  • CARACTERIZAÇÃO DE RESÍDUOS ORIUNDOS DO BENEFICIAMENTO DO MINÉRIO DE FERRO PARA USO EM PAVIMENTAÇÃO

  • Leader : MARIA DEL PILAR DURANTE INGUNZA
  • MEMBRES DE LA BANQUE :
  • MARIA DEL PILAR DURANTE INGUNZA
  • FAGNER ALEXANDRE NUNES DE FRANCA
  • LEONARDO FLAMARION MARQUES CHAVES
  • ENIO FERNANDES AMORIM
  • Data: 25 févr. 2015


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  • A mineração no Brasil possui papel fundamental no desenvolvimento econômico e social, contribuindo diretamente na melhoria de vida da população. Entretanto, a atividade mineradora ainda que seja feita de forma responsável e com um estudo adequado de gestão de resíduos para diminuir o impacto dos seus efeitos, pode vir a causar danos nocivos ao meio ambiente. Outras formas de poluição também são geradas devido à atividade mineradora. A poluição visual provocada pelo armazenamento dos resíduos a céu aberto, além da poluição sonora provocada pelo barulho excessivo das máquinas tanto na extração do minério, como no beneficiamento. Uma forma alternativa de diminuir os impactos ambientais provocados pela mineração é a utilização dos resíduos nas camadas que irão compor os pavimentos das rodovias. Sendo assim, este trabalho se propõe a dar uma destinação adequada aos resíduos oriundos do beneficiamento do minério de ferro, decorrentes da atividade mineradora do grupo de mineração Mhag Serviços e Mineração, na mina do Bonito, localizada no município de Jucurutu, no estado do Rio Grande do Norte. Os resíduos do minério de ferro foram estabilizados com um solo granular proveniente do município de Macaíba, também no estado do Rio Grande do Norte, o qual está sendo utilizado da duplicação da BR-304 referente ao trecho intitulado de Reta Tabajara. O presente trabalho foi desenvolvido em três etapas, sendo a primeira dividida pelos ensaios químicos e mineralógicos, pelos ensaios de caracterização física e pelos ensaios de pavimentação para os resíduos do minério de ferro.  A segunda etapa corresponde aos mesmos ensaios, sendo realizado para o solo granular. A terceira etapa contempla os ensaios citados para três diferentes misturas de resíduos de minério de ferro e solo granular, sendo elas: 15% de resíduos de minério de ferro e 85% de solo granular, 25% de resíduos de minério de ferro e 75% de solo granular, 50% de resíduos de minério de ferro e 50% de solo granular. Os ensaios de limite de liquidez e limite de plasticidade foram realizados a fim de encontrar os índices de consistências, porém os resíduos se comportaram como materiais não plásticos. Foi verificada a viabilidade técnica da utilização dos resíduos oriundos do beneficiamento do minério de ferro, compactado na energia intermediária e modificada, para utilização em camadas de base, sub-base, reforço de subleito e subleito. A incorporação dos resíduos oriundos do beneficiamento do minério de ferro em rodovias proporcionará uma alternativa ao uso de agregados convencionalmente utilizados na pavimentação, além de preservar o meio ambiente.

3
  • JOAO RONYBERTO CAVALCANTE RIBEIRO
  • ANÁLISE PARAMÉTRICA DA ESTABILIDADE DE FALÉSIAS E ESTUDO DE CASO DA PONTA DO PIRAMBU EM TIBAU DO SUL/RN. 

  • Leader : OLAVO FRANCISCO DOS SANTOS JUNIOR
  • MEMBRES DE LA BANQUE :
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • ADA CRISTINA SCUDELARI
  • RICARDO NASCIMENTO FLORES SEVERO
  • ROBERTO COUTINHO
  • Data: 27 févr. 2015


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  • A costa do Estado do Rio Grande do Norte é caracterizada pela presença de dunas e falésias. Estas últimas consistem em taludes com altura de até 40 metros e inclinação variando de 30o a 90o com a horizontal. No entanto, estudos anteriores demonstram que as falésias sofrem recuos periódicos em função da ação do mar na sua base e de movimentos de massas associados à estação chuvosa. Assim, esta dissertação teve como objetivo a avaliação da estabilidade da falésia da Ponta do Pirambu, Município de Tibau do Sul, e a realização de um estudo paramétrico sobre a estabilidade de uma falésia hipotética homogênea considerando como variáveis a coesão do material, a altura da falésia e a inclinação do talude. O estudo na Ponta do Pirambu considerou ainda a possibilidade da existência de uma cobertura coluvionar com espessura variando de 0,50 a 5,00 metros. As análises foram realizadas pelo método de Bishop e comparadas aos outros quatro métodos estudados, utilizando o software GEO5. Na análise paramétrica foram produzidos gráficos que relacionam altura da falésia com a inclinação para fatores de segurança iguais a 1,00 e 1,50; além de gráficos onde é possível obter facilmente o menor fator de segurança a partir da coesão, altura da falésia e sua inclinação. Entende-se que esses gráficos são muito úteis para análises preliminares, para a definição de áreas críticas em mapeamentos de riscos em áreas de falésias e para determinação de uma equação para obtenção do menor fator de segurança em função dos parâmetros de resistência e da geometria de um talude. Os resultados mostraram que a falésia da Ponta do Pirambu está sujeita a movimentos superficiais na parte superior. Admite-se que a falésia se mantém estável em função da vegetação presente na área que seria desestabilizada e pelo fato do solo não ficar completamente saturado na estação chuvosa. Afastando-se a possibilidade das rupturas superficiais a falésia apresenta fator de segurança igual a 2,70, apresentando-se estável em relação à ocorrência de rupturas profundas. Caso ocorra a presença de colúvio com espessura superior a 2,00 metros em trechos da face da falésia, tal fato pode induzir a rupturas localizadas na falésia. 

4
  • PAULO RYCHARDSON FREIRE BESERRA NASCIMENTO
  • CAPACIDADE DE CARGA DE MISTURAS DE SOLO LATERÍTICO E DESBASTES DE PNEUS

  • Leader : YURI DANIEL JATOBA COSTA
  • MEMBRES DE LA BANQUE :
  • YURI DANIEL JATOBA COSTA
  • CARINA MAIA LINS COSTA
  • ALEXANDRE DA COSTA PEREIRA
  • GREGÓRIO LUÍS SILVA ARAÚJO
  • Data: 27 févr. 2015


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  • Os esforços estatais visando alcançar uma melhor infraestrutura para o país têm encontrado algumas barreiras, em especial o atendimento de intransponíveis requisitos de preservação ambiental. Há a necessidade de desenvolvimento de novas técnicas que abandonem o exagero na exploração dos recursos ambientais sem pesar contra o ponto de vista técnico-econômico. O presente estudo trata da avaliação da capacidade de carga de um compósito formado pela mistura de solo laterítico (classificado para estudo como uma areia argilosa) e desbastes de pneumáticos inservíveis. Neste sentido, foi desenvolvido um modelo de aterro rodoviário para se avaliar a capacidade de carga do compósito. Foi avaliado o comportamento do compósito para proporções de mistura de 0, 10, 20 e 40 % em peso. Provas de carga em placa foram realizadas em modelos compactados com cada proporção de mistura. Os modelos foram confeccionados em uma caixa de aço de 1,40 x 1,40 x 0,80 m. Após a compactação de quatro camadas do compósito, um ensaio de placa foi realizado, sendo obtida a curva tensão-deslocamento para o compósito. Dificuldades executivas foram observadas na compactação do aterro com teor de 40 % de borracha. Verificou-se uma redução significativa da capacidade de carga do sistema solo-placa com o aumento do teor de borracha. Uma das principais causas para essa diminuição é a mudança no modo de ruptura entre o solo de referência e os compósitos estudados. O compósito que obteve o melhor desempenho foi aquele com um teor de mistura c = 10%. Além dos ensaios de capacidade de carga através de ensaio de placa, um outro aspecto foi avaliado: a capacidade de suporte dos compósitos comparados com o solo de referência em termos do valor do ISC. Os resultados apontaram uma queda abrupta da capacidade portante nos compósitos. O compósito com o melhor desempenho foi, também, aquele com um teor de mistura c = 10%.

5
  • KLAUS ANDRÉ DE SOUZA MEDEIROS
  • MODELAGEM COMPUTACIONAL PARA AVALIAÇÃO DA INTERAÇÃO ENTRE PAINÉIS DE ALVENARIA E ESTRUTURA DE SUPORTE EM CONCRETO ARMADO

  • Leader : JOEL ARAUJO DO NASCIMENTO NETO
  • MEMBRES DE LA BANQUE :
  • JOEL ARAUJO DO NASCIMENTO NETO
  • DANIEL NELSON MACIEL
  • JOSE NERES DA SILVA FILHO
  • MARCIO ROBERTO SILVA CORRÊA
  • Data: 26 mars 2015


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  • O estudo desenvolvido propõe uma nova modelagem computacional eficiente e de fácil aplicação em situações usuais de projeto para avaliar a interação entre painéis de alvenaria e estrutura de suporte. O modelo proposto simula o comportamento da parede utilizando exclusivamente elementos finitos de barra, compondo assim, um pórtico equivalente. A validação foi realizada sob dois aspectos: primeiramente, mediante estudo de diversos painéis planos genéricos, confrontando-se os resultados obtidos do modelo de pórtico equivalente com os de um modelo de referência, o qual utiliza elementos finitos de casca na discretização das paredes; e numa segunda etapa, comparando-se com os resultados do modelo experimental de Rosenhaupt. As análises consistiram basicamente na avaliação dos deslocamentos verticais e dos esforços nas vigas de apoio, e das tensões na base das paredes. Foram avaliados também, a partir de modelagem plana e tridimensional de algumas paredes de um projeto real, aspectos importantes da interação parede-viga, tais como: presença de aberturas de portas e de janelas, dispostas em qualquer posição; condições de apoio e vinculação das vigas; interferências das amarrações entre paredes; e consideração da ação do vento.

    As análises dos resultados alcançados evidenciaram a eficiência da modelagem proposta, em razão de apresentarem aspectos muito semelhantes na distribuição de tensões e de esforços, sempre com intensidades um pouco maiores do que as dos modelos de referência e experimental.

6
  • RAVENNA MARIA MONTEIRO BARROS
  • Incorporação de Resíduo de cascalho de perfuração de poços de petróleo em formulações cerâmicas. 

  • Leader : WILSON ACCHAR
  • MEMBRES DE LA BANQUE :
  • JAQUELIGIA BRITO DA SILVA
  • CARLOS ALBERTO PASKOCIMAS
  • WILSON ACCHAR
  • VAMBERTO MONTEIRO DA SILVA
  • Data: 20 avr. 2015


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  • Nesta pesquisa será realizado o estudo da incorporação do resíduo de fluido de perfuração de poço de petróleo em formulações cerâmicas, avaliando a sua influência nas propriedades do material cerâmico. Os percentuais de substituição de resíduo serão de 10%, 20% e 30% em relação à massa cerâmica, a sinterização será realizada nas temperaturas de 850°, 950° e 1050º C. As propriedades a serem avaliadas serão Absorção de Água, Retração Linear de Queima, Tensão de Ruptura à Flexão, Porosidade Aparente, Massa Específica Aparente, MEV do ponto de ruptura e Ensaio de Cor.

7
  • LAURENCIO MENEZES DE AQUINO
  • APLICAÇÃO DAS NORMAS DE SEGURANÇA CONTRA INCÊNDIO NO ESTADO DO RIO GRANDE DO NORTE: Uma proposta de atualização.

  • Leader : MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • MEMBRES DE LA BANQUE :
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • MARCOS LACERDA ALMEIDA
  • ANA CECILIA VIEIRA DA NOBREGA
  • Data: 14 juil. 2015


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  • A legislação aplicada à Segurança Contra Incêndio nas edificações e áreas de risco no Rio Grande do Norte, promulgada há mais de quarenta anos, carece de um aprofundado estudo no sentido de atualização do seu texto à luz das novas concepções decorrentes do desenvolvimento científico e tecnológico da segurança contra incêndio e das medidas para controle de pânico. As exigências atualmente aplicadas pelo Corpo de Bombeiros do Estado não estão em consonância com a legislação aprovada, suscitando muitas dúvidas e questionamentos entre projetistas e demais profissionais que atuam nesta área. Esta pesquisa tem por objetivo apresentar a proposta de uma nova legislação de Segurança Contra Incêndio e Pânico para o Estado do Rio Grande do Norte, elaborado através do estudo da legislação e normas técnicas relacionadas à proteção contra incêndio no Brasil e em outros países. Nesse sentido, foi realizada uma pesquisa bibliográfica e documental com especial enfoque à legislação aplicada nos estados brasileiros, notadamente onde a segurança contra incêndio alcançou maior nível de desenvolvimento. Também foi aplicado um questionário aos Corpos de Bombeiros de todo o país, visando apresentar um diagnóstico da atual situação da legislação de Segurança Contra Incêndio no Brasil. Constatou-se que ainda existe uma grande defasagem quanto ao nível de exigência de requisitos de proteção contra incêndio em grande parte dos estados brasileiros, existindo uma tendência na adoção de Instruções Técnicas elaboradas pelo Corpo de Bombeiros do estado de São Paulo, o que já se tornou realidade em muitos estados, uma vez que não existe uma legislação aplicada em âmbito nacional.

8
  • ALISSON GADELHA DE MEDEIROS
  • Análise de durabilidade da Ponte do Rio do Carmo utilizando ensaios não destrutivos, norma DNIT e a metodologia GDE/UnB 

  • Leader : MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • MEMBRES DE LA BANQUE :
  • ALEXANDRE DA COSTA PEREIRA
  • JOSE NERES DA SILVA FILHO
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • Data: 28 août 2015


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  • A durabilidade das estruturas de concreto armado tem motivado muitas pesquisas, considerando os altos custos dos reparos em muitas situações, como é o caso das pontes, bem como os prejuízos causados pela necessidade de interdição quanto aos serviços de recuperação. Neste sentido, este trabalho tem como objetivo avaliar as condições de durabilidade da Ponte do Rio do Carmo com 90,90 metros de extensão. Esta foi construída em 1976 e está localizada no Km 36 da rodovia brasileira BR-110, entre os municípios de Areia Branca/RN e Mossoró/RN, em região de elevada agressividade ambiental. Para realização deste estudo, foram identificadas as manifestações patológicas presentes, utilizando metodologias de inspeções: Norma DNIT 010/2004 – PRO e a GDE/UnB. Com isto, a partir delas, pôde-se verificar que, as maiores incidências dos danos sofridos foram na superestrutura, na mesoestrutura e em outros elementos estruturais, como as vigas de fachada. Ademais, de acordo com este levantamento, foi possível quantificar a deterioração da estrutura; de forma que se obteve nota técnica igual a 3 segundo a norma DNIT, caracterizando-a como uma obra “potencialmente problemática”, e grau de deterioração global da estrutura (Gd) igual 65,05, classificando-a em nível “Alto”. Em comparativo entre ambas metodologias aplicadas, a mais conservadora foi a GDE/UnB, devido a riqueza de detalhes em sua análise. Quanto, a realização dos ensaios não destrutivos, mostrou-se boa homogeneidade do concreto perante o ensaio de esclerometria. Para as medidas de ultrassom, foi identificada a qualidade do concreto como “regular” e possibilitou a estimativa do módulo de elasticidade e resistência em 17,60 GPa e 13,51 MPa, respectivamente. Já o ensaio de profundidade de carbonatação, foram aferidas medidas em valores de 0,00 a 19,00 mm e, no o ensaio de presença de cloretos, verificaram-se maiores medidas, sendo a maior delas igual 22,80 mm. Porém, ambas não atingiram a profundidade do aço, 30 mm. No ensaio de potencial de corrosão, a maior parte da medição foi numa faixa de -150 a -250 mV, que indica probabilidades de 10 a 90% de corrosão. Todos esses resultados podem concluir que, a Ponte do Rio do Carmo, necessita de reparos nos elementos estudados nesta pesquisa e aliados outras inspeções mais detalhadas, poderá se planejar a solução mais adequada quanto aos aspectos de segurança e economia.

9
  • JOSE DANIEL JALES SILVA
  • Avaliação da potencialidade de incorporação de um lodo de uma indústria de produtos de limpeza como adição mineral em concretos de cimento Portland

  • Leader : MARIA DEL PILAR DURANTE INGUNZA
  • MEMBRES DE LA BANQUE :
  • MARIA DEL PILAR DURANTE INGUNZA
  • ANDREZA KELLY COSTA NOBREGA
  • GLADIS CAMARINI
  • LIANA FILGUEIRA ALBUQUERQUE
  • Data: 24 nov. 2015


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  • A geração de resíduos industriais tem aumentado cada vez mais nas últimas décadas, motivando estudos sobre uma destinação ambientalmente correta e sustentável e que também represente vantagens para seus geradores. Neste contexto estão inseridas duas empresas do nicho de produtos de limpeza que estão localizadas no município de São José do Mipibu e produzem um lodo industrial em estação de tratamento de efluentes, constituindo a abordagem principal desta pesquisa. Diante disto, verificou-se o potencial de incorporação do referido lodo em matriz de cimento Portland como adição mineral para a fabricação de concretos, dado o elevado potencial de imobilização de resíduos na matriz endurecida desse material, sendo estes utilizados posteriormente na própria empresa para confecção de artigos pré-moldados. Foram adicionados diferentes teores de lodo (5, 10, 15 e 20%) em um traço comum (1:2:3), sendo avaliadas suas implicações técnicas e microestruturais por meio de ensaios de trabalhabilidade no estado fresco e resistência à compressão, porosidade total e microscopia eletrônica de varredura (MEV) no estado endurecido. Os resultados obtidos demonstraram a viabilidade do processo tanto do ponto de vista técnico e ambiental quanto econômico. Todos os concretos produzidos com resíduo apresentaram uma aumento de trabalhabilidade atribuído a natureza do resíduo que possuía substâncias surfactantes capazes de adsorver minúsculas partículas de ar na massa. Em contrapartida, para todos os teores foram obtidas resistências à compressão inferiores ao concreto padrão, com uma redução de 39%, para as amostras com 20% de lodo. Isso se deve, principalmente a um aumento de porosidade na zona de transição desses materiais, resultante de maior formação de etringita em detrimento a formação de CSH, principal composto cimentante, mas que, ainda assim, permite o uso desses concretos para a fabricação de artigos com caráter não estrutural, como pisos pré-moldados. Ademais, a absorção de água e índice de vazios aumentaram levemente para todas as amostras, com exceção do concreto com 20% de resíduo que apresentou redução para os dois parâmetros. Diante deste contexto, o teor máximo recomendado é de 20%, constituindo uma proporção significativa e capaz de destinar sustentavelmente todo o resíduo gerado na indústria.

10
  • JOSÉ EURICO DE QUEIROS
  • Avaliação do desempenho de argamassas à base de cimento Portland para rejuntamento de placas cerâmicas tipo II com adição de pó de borracha de pneus

  • Leader : MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • MEMBRES DE LA BANQUE :
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • EDILBERTO VITORINO DE BORJA
  • Data: 15 déc. 2015


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  • Neste trabalho, avalia-se o desempenho de argamassas à base de cimento Portland para rejuntamento de placas cerâmicas tipo II com adição de pó de borracha de pneus inservíveis. Apresenta-se uma revisão bibliográfica sobre o tema (SEGRE, 1999; MENEGUINI, 2003; FERREIRA, 2009; GUIMARÃES, 1997; FIORITO, 1994), em que se faz a ancoragem teórico-metodológica de todo o processo investigativo. O universo analisado compreende uma amostra de argamassa para rejuntamento de placas cerâmicas tipo II convencional (amostra de referência) e de mais cinco amostras de argamassas para rejuntamento de placas cerâmicas tipo II, compostas com adição de pó de borracha de pneu inservíveis, nas respectivas proporções de 4, 8, 12, 16 e 20 %.

    Essas amostras de argamassas foram submetidas aos ensaios de determinação do índice de consistência (NBR 13276:2005), retenção de água (NBR 14992 Anexo B:2003), permeabilidade aos 240 minutos (NBR 14992 Anexo G:2003), Absorção de água por imersão (NBR 9781:2013), resistência à compressão (NBR 14992 Anexo D:2003), resistência à tração na flexão (NBR 13279:2005), resistência de aderência à tração (NBR 14081 Parte 4:2012) e densidade de massa no estado endurecido (NBR 13280:2005). Constatou-se, a partir das análises dos resultados obtidos nos ensaios, a seguinte situação: a argamassa de referência utilizada atendeu às exigências estabelecidas nas normas de especificações correspondentes para apenas seis do total de oito parâmetros avaliados na pesquisa; a argamassa com adição de 4,0 % de pó de borracha de pneu atendeu às exigências estabelecidas nas normas de especificações correspondentes para, apenas, a resistência à compressão e a resistência de aderência à tração; as demais argamassas com adição de 8,0 %, 12,0 %, 16,0 % e 20,0 % de pó de borracha de pneu atenderam às exigências das normas de especificações correspondentes, apenas quanto à resistência de aderência à tração. Esse resultado evidencia a conclusão de que a adição de pó de borracha de pneu não confere melhoria de desempenho às argamassas.

11
  • ARTUR MOURA
  • PLANEJANDO COM LEAN CONSTRUCTION: DIRETRIZES PARA IMPLEMENTAÇÃO DA CONSTRUÇÃO ENXUTA EM OBRAS

     

  • Leader : MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • MEMBRES DE LA BANQUE :
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • MARIANA RODRIGUES DE ALMEIDA
  • RENATO SAMUEL BARBOSA DE ARAÚJO
  • Data: 18 déc. 2015


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  • Atualmente, vive-se em uma época de escassez de crédito provocada pela crise financeira mundial, e a exemplo do ocorrido no passado, cabem aos mais diversos setores e segmentos da sociedade buscar meios para se reinventar. Nesse contexto, a Lean Construction se apresenta como uma forte alternativa de gestão da produção para empresas do segmento de construção civil. Advinda da mentalidade enxuta que teve sua origem no Japão no período pós-guerra e se difundiu pelo mundo em épocas de extrema escassez com a crise do petróleo. Na prática a Lean Construction é uma filosofia que busca aperfeiçoar o processo de gestão da produção, maximizando o fluxo do valor a partir da ótica do cliente através da eliminação das perdas. E prospera em ambientes e culturas que consideram a escassez de recursos como algo natural, aplicando-se tanto a épocas de crise macroeconômicas como de prosperidade. O Planejamento e Controle da Produção – PCP apresenta-se como alicerce fundamental para que as empresas se protejam diante das flutuações econômicas, visando sua sobrevivência e sucesso no disputado mercado. Motivado pela carência de discursão do tema na academia local, e, pela identificação dos 93,33% de construtoras que não fazem o uso de metodológico de ferramentas para o PCP no estado, a presente dissertação objetiva estudar e propor a implementação da construção enxuta na metodologia de planejar empreendimentos aplicados em canteiros de obras. Nesta caracterizou-se o sistema de gestão da produção de uma empresa construtora, apontando as principais causas da ineficácia relacionadas a consequente baixa no desempenho de um de seus empreendimentos. Na sequência implementou-se o PCP com o uso de ferramentas para atendimento aos princípios da construção enxuta. Sendo este monitorado através de indicadores que proporcionaram aos gestores a visão gerencial do processo de controle das ações e mecanismos de proteção da produção. Todas as diretrizes de implementação e aplicação deste modelo de gestão, foram expostas  de maneira simplificada, prática e eficiente, visando quebrar a resistência de novas práticas e antigos paradigmas do setor.

2014
Thèses
1
  • FELIPE MURILO SILVA DA COSTA
  • ESTUDO DA VIABILIDADE DA UTILIZAÇÃO DE CINZA DE LODO DE ESGOTO COMO ADIÇÃO EM ARGAMASSA DE CIMENTO PORTLAND.

  • Leader : MARIA DEL PILAR DURANTE INGUNZA
  • MEMBRES DE LA BANQUE :
  • GLADIS CAMARINI
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • MARIA DEL PILAR DURANTE INGUNZA
  • Data: 24 janv. 2014


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  • O uso de lodo de esgoto como matéria-prima se insere dentro do processo de reciclagem de resíduos, fundamental no modelo de sustentabilidade ambiental atual. A reciclagem de resíduos vem se consolidando como uma solução sustentável, técnica e ambientalmente correta. Apesar de apresentar composição e características muito variáveis, o lodo de esgoto, pode ser considerado como um resíduo com alto potencial de reciclagem no setor da construção civil. Neste trabalho foi estudada a viabilidade de utilização de cinza de lodo de esgoto como adição em argamassa de cimento Portland no traço 1:3 em massa considerado o traço padrão. Foram estudadas adições desta cinza nas proporções de 5%, 10%, 15%, 20%, 25% e 30% em relação à massa de cimento. A metodologia foi centrada na caracterização dos materiais por meio de ensaios físicos, químicas, mecânicos, ambientais e microestruturais, seguida pela produção das argamassas, e finalizada pelos ensaios de caracterização das argamassas no estado fresco, através do índice de consistência, teor de ar incorporado, densidade de massa e retenção de água, e no estado endurecido através da densidade de massa, absorção de água por capilaridade, coeficiente de capilaridade, resistência à compressão, resistência à tração na flexão, resistência de aderência à tração e da análise microscópica. Após comparar a argamassa padrão com as argamassas com adição da cinza, conclui-se que a cinza de lodo de esgoto não comprometeu a integridade e propriedades das argamassas com adição, inclusive aumentando a resistência à compressão e tração, sendo 20% a porcentagem mais indicada. Assim, torna-se viável a adição de cinza de lodo de esgoto em argamassa de cimento Portland para o traço estudado. 

2
  • GILVAN BEZERRA DOS SANTOS JUNIOR
  • ESTUDO NUMÉRICO DO COMPORTAMENTO DE MUROS DE ARRIMO EM ALVENARIA ESTRUTURAL DE BLOCOS VAZADOS

  • Leader : JOEL ARAUJO DO NASCIMENTO NETO
  • MEMBRES DE LA BANQUE :
  • JOEL ARAUJO DO NASCIMENTO NETO
  • DANIEL NELSON MACIEL
  • ALEXANDRE ARAÚJO BERTINI
  • Data: 7 févr. 2014


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  • As estruturas de alvenaria solicitadas por elevados esforços de flexão podem necessitar, dada a baixa resistência à tração, de elevadas taxas de armadura; de maior resistência à compressão da alvenaria; de elementos estruturais com maiores dimensões ou mesmo um rearranjo desses elementos para possibilitar o emprego da alvenaria. O estudo ora apresentado tem por objetivo avaliar a rigidez, a distribuição de esforços e o efeito da distribuição de cintas e de elementos verticais (contrafortes) no caso de muros de arrimo de alvenaria estrutural de blocos. Para tanto, foram realizadas modelagens numéricas de arranjos típicos de muro, variando a quantidade e o posicionamento de cintas horizontais, o espaçamento entre os contrafortes, além de incluir elementos simulando as reações do solo de apoio na fundação do muro. A modelagem numérica realizada empregou a estratégia de macromodelagem em que os blocos, a argamassa e o graute são discretizados pelo volume padrão representativo do comportamento elástico da alvenaria. Alternativamente, os resultados do modelo numérico foram comparados com os de modelos simplificados comumente adotados nos projetos desse tipo de elemento estrutural. A análise dos resultados consistiu na verificação dos deslocamentos transversais, na distribuição das tensões principais (para balizar um futuro modelo de bielas e tirantes e os modos de ruptura), na distribuição das tensões de cisalhamento, e na obtenção de diagramas de momento fletor. A partir das análises foi possível concluir que não apenas a quantidade, mas também a forma de distribuição das cintas é um fator relevante para a distribuição dos esforços no painel fletido (pano de alvenaria), a inclusão dos elementos de fundação alterou significativamente o comportamento do muro, principalmente os deslocamentos transversais, além de ter sido proposta uma nova forma de consideração de flanges na seção resistente do contraforte.

3
  • CARLINDO AVELINO BEZERRA NETO
  • DESENVOLVIMENTO DE UM EQUIPAMENTO PARA AVALIAÇÃO DO DESEMPENHO DE GEOMANTAS

  • Leader : CARINA MAIA LINS COSTA
  • MEMBRES DE LA BANQUE :
  • ALEXANDRE DA COSTA PEREIRA
  • CARINA MAIA LINS COSTA
  • JOSÉ RAMON BARROS CANTALICE
  • YURI DANIEL JATOBA COSTA
  • Data: 21 févr. 2014


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  • O controle sobre os processos erosivos é uma necessidade constatada em vários segmentos da engenharia. A movimentação de terra necessária para a execução de taludes rodoviários, por exemplo, pode resultar em taludes de corte ou aterro vulneráveis à erosão superficial. Dentre as alternativas tecnológicas para controle de erosão a utilização de geossintéticos se apresenta como uma solução potencial. A referida aplicação encontra-se em amplo desenvolvimento em alguns países como, por exemplo, nos EUA. No Brasil, a especificação de geossintéticos para controle de erosão é limitada pela ausência de caracterização desses produtos e de normas nacionais, sendo a única fonte técnica de informação, os catálogos dos fabricantes. Neste contexto, o objetivo deste trabalho é construir um equipamento e desenvolver métodos de ensaio para caracterização e avaliação de geossintéticos utilizados no controle de erosão superficial. Além de um simulador de chuvas, o equipamento é composto por uma bancada de testes formada por: rampa de escoamento, mesa de suporte e núcleos de solo. Utilizando a bancada construída, foram realizados ensaios para avaliar o funcionamento do equipamento e o desempenho de uma geomanta na redução da taxa de erosão superficial. Os ensaios foram realizados com intensidades de precipitação de 100 ± 4mm/h e 150 ± 4mm/h, durante 30 minutos, com intervalo de leitura de 5 minutos. Os resultados obtidos nos ensaios sem a presença da geomanta mostraram uma perda de solo acentuada durante as chuvas simuladas, com uma tendência de crescimento linear da perda de solo acumulada em função do tempo de ensaio. Nos ensaios realizados com a presença da geomanta observou-se a ação de proteção do geossintéticos com uma redução da ordem de 90% da perda de solo acumulada para todas as intensidades de chuvas utilizadas.

4
  • ESTEFANE GEORGE MACEDO DE LACERDA
  • ANÁLISE NÃO-LINEAR DE TRELIÇAS PELO

    MÉTODO DOS ELEMENTOS FINITOS POSICIONAL

  • Leader : ADA CRISTINA SCUDELARI
  • MEMBRES DE LA BANQUE :
  • ADA CRISTINA SCUDELARI
  • DANIEL NELSON MACIEL
  • JOÃO CARLOS ARANTES COSTA JÚNIOR
  • ALEXANDRE JOSÉ SOARES MINÁ
  • Data: 28 févr. 2014


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  • Este trabalho apresenta a formulação posicional não linear geométrica para treliças usando diferentes medidas de deformação. A formulação posicional é uma abordagem alternativa para problemas não-lineares. Esta formulação considera as posições nodais como variáveis do sistema não linear em vez dos deslocamentos (que é largamente utilizado na literatura). O trabalho também descreve o método do comprimento de arco usado para traçar caminhos de equilíbrio com snap-through e snap-back. Aplicações numéricas com treliças já consagradas na literatura e comparações com outros trabalhos são fornecidos para provar a acurácia da formulação proposta.

5
  • RUBENS DIEGO FERNANDES ALVES
  • ESTUDO DA PREVISÃO DA CARGA DE RUPTURA DE ESTACAS PRÉ-MOLDADAS DE CONCRETO

  • Leader : OLAVO FRANCISCO DOS SANTOS JUNIOR
  • MEMBRES DE LA BANQUE :
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • LEONARDO FLAMARION MARQUES CHAVES
  • RAIMUNDO LEIDIMAR BEZERRA
  • Data: 28 févr. 2014


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  • A partir de ensaios de provas de carga de estacas pré-moldadas de concreto e sondagens do tipo SPT, realizou-se um estudo da obtenção da carga de ruptura da fundação através de métodos semiempíricos, elásticos e de extrapolação da curva carga-recalque. Após isso, realizaram-se comparações entre os diversos métodos utilizados para dois tipos de solo, um de comportamento granular e outro coesivo.
    Para obtenção dos parâmetros do solo a serem utilizados nos métodos estabeleceuse correlações empíricas com o índice de resistência a penetração (NSPT). As curvas carga-recalque das estacas também são analisadas. Diante das comparações estabelecidas indica-se o método mais confiável para cada tipo de solo.

6
  • NEUBER NASCIMENTO DE ARAUJO
  • Desempenho de argamassas produzidas com agregados reciclados oriundos do resíduo de construção e demolição da Grande Natal/RN

  • Leader : MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • MEMBRES DE LA BANQUE :
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • MARIA DEL PILAR DURANTE INGUNZA
  • ANDREZA KELLY COSTA NOBREGA
  • Data: 28 mars 2014


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  • A indústria da construção civil é responsável gerar uma grande quantidade de resíduos em função de suas atividades. Como consequência, é perceptível a ocorrência de problemas ambientais mediante o seu descarte em locais inadequados. Diante dessa problemática, alguns estudos vêm sendo desenvolvidos com o objetivo de desenvolver tecnologias e alternativas de reciclagem para os resíduos de construção e demolição (RCD), motivados pela escassez de recursos naturais e pela diminuição dos problemas ambientais gerados em função do descarte irregular desse resíduo. A pesquisa tem por objetivo caracterizar os agregados produzidos a partir do resíduo de construção e demolição (RCD) produzidos na Grande Natal-RN e analisar o desempenho de argamassas de revestimento produzidas com os agregados reciclados. O estudo inclui a caracterização química, física e microestrutural dos agregados reciclados, assim como a realização de análises microscópicas e ensaios laboratoriais no estado fresco (índice de consistência, retenção de água, densidade de massa e teor de ar incorporado) e no estado endurecido (resistência a compressão, resistência a tração na flexão, absorção de água por imersão e por capilaridade, densidade de massa e índice de vazios), para argamassas produzidas a partir de diferentes teores de substituição de agregados (0, 20%, 40%, 60%, 80% e 100%). Os resultados obtidos foram satisfatórios, proporcionando às argamassas com agregados reciclados, valores menores de densidade de massa e módulo de elasticidade dinâmico, assim como índices mais elevados de absorção e de porosidade. Em relação à resistência mecânica, apresentaram valores maiores em relação à argamassa de referência. Os experimentos conduziram a concluir que do ponto de vista técnico e econômico, as argamassas produzidas com agregados reciclados podem ser utilizados na construção civil, desde que haja um controle eficiente nos processos de produção do agregado reciclado e na dosagem das argamassas.

7
  • EDMILSON CORREIA RODRIGUES
  • Análise numérica do efeito de fatores influentes da reação álcali-agregado no desempenho de estruturas de concreto.

  • Leader : EDMILSON LIRA MADUREIRA
  • MEMBRES DE LA BANQUE :
  • EDMILSON LIRA MADUREIRA
  • DANIEL NELSON MACIEL
  • JOSE NERES DA SILVA FILHO
  • KLEBER CAVALCANTI CABRAL
  • Data: 7 avr. 2014


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  • O objetivo deste trabalho é a simulação numérica do desempenho Mecânico de elementos estruturais de concreto afetados pela Reação Álcali-Agregado. Refere-se à patologia, reportada por Stanton em 1940, que assumiu ênfase a partir da década de 80, quando foram relatadas suas consequências, incluindo fissuração, ruína e perda de funcionalidade. A carência de formulação teórica conclusiva, motivada sobretudo pelo fato de os ensaios experimentais demandarem grandes períodos de tempo, dificulta a solução dos problemas decorrentes da RAA. A simulação numérica do fenômeno em pauta é instrumento útil para a previsão de danos, bem como para a especificação dos serviços de recuperação da estrutura deteriorada e da época apropriada para realizá-los. Constitui, inclusive, recurso eficaz para respaldar modificações normativas direcionadas a projetos estruturais. O código computacional de suporte deste trabalho utiliza-se da aproximação por elementos finitos sobre formulação ortotrópica não linear, e, um modelo termodinâmico para avaliar as deformações por RAA.

8
  • HAZEN WILLIAN BEZERRA PEREIRA
  • IDENTIFICAÇÃO DAS CONDIÇÕES GERAIS DE CONSERVAÇÃO DOS RESERVATÓRIOS INTEGRANTES DO SISTEMA DE ABASTECIMENTO DE ÁGUA DE NATAL


  • Leader : MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • MEMBRES DE LA BANQUE :
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • JOSE NERES DA SILVA FILHO
  • PAULO ALYSSON BRILHANTE FAHEINA DE SOUZA
  • JOSÉ GETULIO GOMES DE SOUSA
  • Data: 23 mai 2014


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  • As obras de infraestrutura englobam áreas estratégicas para o desenvolvimento da sociedade. Neste âmbito as obras de saneamento são de suma importância para o desenvolvimento social. Com o fornecimento de água em quantidade suficiente e qualidade satisfatória, juntamente com a coleta e o devido tratamento dos efluentes domésticos, a sociedade torna-se menos susceptível às doenças de veiculação hídricas.

    Tanto o Sistema de Abastecimento de Água quanto o de Esgotamento Sanitário dependem, para seu perfeito funcionamento, de reservatórios, seja para o acumulo de água para atendimento da população, seja para a devida retenção e tratamento dos efluentes domésticos.

    Essas estruturas apresentam características bem específicas de utilização, porque o microclima criado em seu entorno caracteriza-se pela elevada umidade relativa do ar e pela presença de substâncias danosas ao concreto, como os íons cloretos presente na água.

    Os reservatórios que integram o Sistema de Abastecimento de Água e Natal foram, em sua maioria, construídos entre as décadas de 1970 e 1980, período em que o meio técnico-científico não dispunha de estudos aprofundados sobre o mecanismo de deterioração do concreto armado. Por isso, esses reservatórios sofrem com o processo acelerado de degradação, apresentando diversas manifestações patológicas visivelmente identificáveis.

    Diante dessa problemática este trabalho visa identificar as principais manifestações patológicas presentes em doze reservatórios integrantes do Sistema de Abastecimento de Água de Natal, e propondo um plano de recuperação.

9
  • ADLA KELLEN DIONISIO SOUSA
  • ARGAMASSAS DO GRUPO ESCOLAR AUGUSTO SEVERO/RN: CARACTERIZAÇÃO E INCIDÊNCIA DE MANIFESTAÇÕES PATOLÓGICAS

  • Leader : MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • MEMBRES DE LA BANQUE :
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • JOSE NERES DA SILVA FILHO
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • ANGELA BORGES MASUERO
  • Data: 30 mai 2014


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  • A busca pela preservação do patrimônio cultural deve ser uma constante, para que
    não haja a perda da identidade histórica e cultural de um país. Como parte deste
    patrimônio cultural, destaca-se a importância das edificações históricas. Para que os
    princípios de restauro sejam atendidos é de suma importância conhecer o estado de
    conservação desses bens e os materiais existentes. Diante do exposto, este
    trabalho tem como objetivo estudar as manifestações patológicas presentes nos
    revestimentos argamassados, bem como caracterizar as argamassas, de maior valor
    patrimonial, do Grupo Escolar Augusto Severo. Para isso, foi realizado um
    levantamento histórico da edificação, visitas in loco com observação visual e registro
    fotográfico, coleta de amostras de argamassas de revestimento e caracterização por
    meio de análise visual e laboratorial, FRX, DRX, TG/DTG e MEV-EDS. A partir das
    observações realizadas, foram identificadas manifestações patológicas como:
    fissuras, desprendimento do revestimento, sujidade, eflorescência, mofo e bolor,
    além da utilização de material inadequado à base de cimento. Constatou-se que as
    manifestações patológicas foram intensificadas devido à falta de cobertura em
    alguns pontos e, sobretudo pelo abandono da edificação, que há muitos anos não
    passa por restauração ou qualquer outro tipo de manutenção preventiva e corretiva.
    Os resultados das técnicas em laboratório indicaram que as argamassas estudadas
    são à base de cal, de natureza calcítica, e agregado silicoso, com presença de argila
    em duas amostras. Das amostras coletadas, duas são compostas por cal, areia e
    argila e duas por cal e areia. Neste sentido, ressalta-se que é de relevante
    importância a realização de inspeções e manutenções periódicas, bem como a
    realização de restauração com a utilização de material compatível com o original.

10
  • ANDRE TABOSA FERNANDES DE SANTA CRUZ GERAB
  • Utilização do rejeito grosso do beneficiamento da scheelita na pavimentação.

  • Leader : MARIA DEL PILAR DURANTE INGUNZA
  • MEMBRES DE LA BANQUE :
  • MARIA DEL PILAR DURANTE INGUNZA
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • LUIS FERNANDO MARTINS RIBEIRO
  • RICARDO NASCIMENTO FLORES SEVERO
  • Data: 30 mai 2014


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  • A mineração é uma atividade de grande valor econômico e social, auxiliando no desenvolvimento do país. Por outro lado, pode ser extremamente danosa ao meio ambiente caso não exista um adequado estudo de gestão de resíduo como medida mitigadora de seus efeitos. Exemplo de alguns desses efeitos nocivos são a poluição das águas, do solo e do ar.

    Existem outros tipos de poluições geradas pelas atividades mineradoras, como a poluição visual, devido à estocagem dos rejeitos por muitas vezes realizados a céu aberto, modificado a paisagem local; a poluição sonora devido aos ruídos provocados pelas maquinas, dentre outros.

    Uma das formas de ser amenizar os impactos ambientais gerados pela mineração é a gestão adequada de seus rejeitos, através, por exemplo, da sua utilização em construção de rodovias.

    Com esse intuito, este trabalho se propõe a dar uma destinação adequada os rejeitos oriundos do beneficiamento da scheelita, decorrentes da atividade mineradora do grupo de mineração Tomaz Salustino, na mina Brejuí, localizada no município de Currais Novos, no estado do Rio Grande do Norte.

    O presente trabalho foi desenvolvido quatro etapas, sendo que a primeira engloba os ensaios químicos e mineralógicos, de DRX e FRX em que se pretende descobrir a composição do material estudado. A etapa seguinte compreende a caracterização física do rejeito, por meio de ensaios de granulometria e massa específica dos sólidos, limite de liquidez e limite de plasticidade. A terceira etapa contempla os ensaios específicos da pavimentação, por assim dizer, o ensaio de compactação Proctor e o ensaio de Índice de Suporte Califórnia. Por fim, a quarta etapa compreende a caracterização mecânica, representado pelos ensaios de cisalhamento direto, tanto na condição seca quanto inundada.

    Foi verificada a viabilidade técnica da utilização do rejeito grosso oriundo do beneficiamento da scheelita, compactado na energia modificada, para utilização em camadas de sub-base. Para o rejeito moldado nas energias intermediária e normal é viável a sua utilização como camadas menos nobres, como reforço de subleito e subleito.

    A incorporação dos rejeitos do beneficiamento do Scheelita em rodovias proporcionará uma alternativa ao uso de agregados convencionalmente utilizados na pavimentação, uma destinação adequada dos rejeitos da scheelita, como também a preservação ambiental.

11
  • GABRIELA BARBOSA BRUNO
  • CONTRIBUIÇÃO NA CARACTERIZAÇÃO DE AGREGADOS COMERCIALIZADOS NO RIO GRANDE DO NORTE COM ÊNFASE NA REAÇÃO ÁLCALI-AGREGADO

  • Leader : MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • MEMBRES DE LA BANQUE :
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • JOSE NERES DA SILVA FILHO
  • MARCOS ALYSSANDRO SOARES DOS ANJOS
  • ANA CECILIA VIEIRA DA NOBREGA
  • Data: 4 août 2014


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  • Existem várias formas de deterioração do concreto, dentre elas, a reação álcali-agregado (RAA) está inserida na categoria de degradação através de processo químico. Como resultado ocorre uma interação entre os componentes do concreto que o fragilizam, podendo causar fissuração, perda de resistência, aumento da deformação, redução da durabilidade, além de outros prejuízos. Existe bastante conhecimento difundido sobre a prevenção da reação, porém o mesmo não pode ser dito acerca do seu mecanismo, inclusive sobre formas de reparo e maneiras de evitar sua continuidade. O presente trabalho tem por objetivo analisar as características dos agregados comercializados no Rio Grande do Norte (RN), enfatizando o seu comportamento com relação à reação álcali agregado através do ensaio de reatividade recomendado por norma, além de análises das propriedades da argamassa após exposição às condições do ensaio de reatividade, avaliando a resistência à compressão, tração na flexão, propriedades elásticas e análises microestruturais, empregando diferentes tipos de cimento. Os resultados não indicaram presenças de formas reativas nos agregados do RN, houveram apenas pequenos pontos onde a reação se desenvolveu mas no geral não foram encontradas expansões acima das especificadas pela norma. Com relação à comparação do comportamento dos dois tipos de cimento, não foram encontradas grandes diferenças nas propriedades da argamassa.

12
  • LEONARDO HENRIQUE BORGES DE OLIVEIRA
  • Modelagem numérica de uma estrutura de contenção de estacas espaçadas atirantadas em areia

  • Leader : YURI DANIEL JATOBA COSTA
  • MEMBRES DE LA BANQUE :
  • CARINA MAIA LINS COSTA
  • CARLOS ALBERTO LAURO VARGAS
  • JOEL ARAUJO DO NASCIMENTO NETO
  • YURI DANIEL JATOBA COSTA
  • Data: 17 oct. 2014


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  •  Os projetos de estruturas de contenção envolvem fatores de plastificação, carregamento e descarregamento de maciços, protensão, deslocamentos excessivos e empuxos de terra e água. Além disso, a interação entre o solo contido e a estrutura executada é bastante complexa e de difícil previsão. Apesar do avanço das técnicas de simulação numérica e monitoramento dos esforços e deslocamentos através de instrumentação, a formulação dos projetos ainda se dá por métodos clássicos, cujas hipóteses simplificadoras podem superdimensionar os elementos constituintes. Neste trabalho, realizou-se um estudo numérico tridimensional de uma estrutura de contenção através do método de elementos finitos (MEF). A estrutura de contenção estudada é composta por estacas espaçadas e tirantes. Os resultados numéricos obtidos foram comparados a dados obtidos de uma instrumentação em campo. Avaliou-se a influência do posicionamento de uma ou duas linha de tirantes ao longo da profundidade e os efeitos causados pela execução de uma laje vinculada à contenção. Estudou-se, ainda, o fenômeno de arqueamento que ocorre entre as estacas, variando-se o espaçamento entre faces de estacas para estudar seus efeitos nas tensões e deslocamentos horizontais. O estudo do posicionamento de uma linha de tirantes ativos indicou uma faixa compreendida entre 0,3 e 0,5 vezes a altura de escavação como aquela que gera os menores deslocamentos horizontais da estrutura. O estudo com duas linhas de tirantes mostrou que a posição da linha superior no nível -2,05m e da linha inferior no nível -3,50m resulta nos menores deslocamentos horizontais. A laje vinculada à contenção diminuiu os deslocamentos horizontais em 0,14% vezes a profundidade de escavação. Com relação ao arqueamento, as análises mostraram uma faixa ótima de espaçamentos entre as faces das estacas compreendido entre e vezes o diâmetro da estaca.

13
  • LUCAS DA SILVA MORAES
  • Análises Numéricas de Dutos Enterrados Sujeitos a Interações Longitudinais

  • Leader : YURI DANIEL JATOBA COSTA
  • MEMBRES DE LA BANQUE :
  • YURI DANIEL JATOBA COSTA
  • CARINA MAIA LINS COSTA
  • FERNANDO SABOYA ALBUQUERQUE JUNIOR
  • Data: 3 nov. 2014


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  • A  grande  extensão  de  uma  dutovia  pode  conduzir  a  inúmeras  situações  particulares  de interação  longitudinal  com  o  solo.  Apesar  do  grande  progresso  alcançado  sobre  a  compreensão  dos  mais  diversos  aspectos  do  comportamento  de  dutos  enterrados,  pouca atenção tem sido dispensada ao comportamento longitudinal dessas estruturas. O presente  projeto  de  pesquisa  tem  como  objetivo desenvolver  um  estudo  através  de  análises  numéricas  tridimensionais  sobre  o  comportamento  mecânico  de  dutos  enterrados  em  condições  que  mobilizem  sua  interação  longitudinal.  Serão  analisadas  instalações  de  dutos sujeitos a perda de apoio e a elevação em uma determinada região  da   tubulação.   Serão   realizadas   análises   paramétricas   amplas   das   diversas   variáveis  envolvidas nas condições propostas para estudo, como, por exemplo, altura de cobertura de solo,  rigidez  relativa  solo?duto  e  extensão  da  zona solicitada.  Dentre  outros  aspectos,  os  resultados  obtidos  permitirão  uma  avaliação  detalhada  da  redistribuição  das  tensões  no maciço de solo e dos esforços e deflexões ao longo do duto. Espera?se, com este trabalho, esclarecer  importantes  questões  com  respeito  ao  comportamento  longitudinal  de  dutos enterrados,  contribuindo  de  forma  significativa  para  a  melhoria  do  projeto  geotécnico dessas estruturas.

14
  • ANDRE LUIZ LOPES TOLEDO
  • COMPORTAMENTO GEOTÉCNICO DE MISTURAS DE SOLO E RESÍDUOS DE PERFURAÇÃO ONSHORE

  • Leader : CARINA MAIA LINS COSTA
  • MEMBRES DE LA BANQUE :
  • CARINA MAIA LINS COSTA
  • NILTON DE SOUZA CAMPELO
  • YURI DANIEL JATOBA COSTA
  • Data: 17 nov. 2014


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  • A perfuração de poços para extração de petróleo gera, entre outros resíduos, fragmentos de rochas e solos. Estes fragmentos são denominados cascalho de perfuração de petróleo ou simplesmente resíduo de perfuração de petróleo. Estes fragmentos são imersos nos chamados fluidos de perfuração – material de base oleosa, aquosa ou sintética que serve para estabilizar os poços e lubrificar os elementos mecânicos de perfuração.  Nos locais de exploração onshore são formados grandes depósitos de cascalho de perfuração, material de onerosa destinação final. No Rio Grande do Norte, a produção mensal de cascalho é estimada em aproximadamente 1.300 toneladas. Entra as soluções ambientais para este resíduo está a mistura com solo, como forma de diminuir a concentração dos contaminantes presentes – principalmente os metais pesados e hidrocarbonetos. Em especial a adição diretamente em vias de serviço dos locais de exploração torna-se uma alternativa interessante logística e economicamente. Este trabalho realiza a caracterização do resíduo retirado de uma região de extração no Rio Grande do Norte, através dos ensaios de granulometria, LL, LP, DRX e FRX e ainda executa misturas em percentuais crescentes de 2,5%, 5%, 10 e 15% de resíduo adicionado a um solo conhecido. Estas misturas são submetidas aos ensaios de compactação, CBR, cisalhamento direto e adensamento, com o objetivo de utilizá-las em corpos de aterro. Os resultados dos ensaios são comparados com as normas vigentes do DNIT para execução de aterros. Os resultados encontrados nos ensaios das misturas atendem aos parâmetros mínimos, permitindo, sob ponto de vista da análise geotécnica, a utilização dessas misturas de solo e resíduo.

15
  • DESIREE ALVES DE OLIVEIRA
  • Análise do fluxo d’água na barragem Engenheiro Armando Ribeiro Gonçalves – Açu/RN

  • Leader : OLAVO FRANCISCO DOS SANTOS JUNIOR
  • MEMBRES DE LA BANQUE :
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • ADA CRISTINA SCUDELARI
  • FRANCISCO CHAGAS DA SILVA FILHO
  • OSVALDO DE FREITAS NETO
  • Data: 19 déc. 2014


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  • A solução da equação diferencial parcial de problemas de percolação é difícil de ser encontrada, sua utilização é de extrema limitação porque apresenta resultados exatos apenas para situações bastante definidas. Para contornar este problema usualmente são utilizados softwares com base em diferenças finitas e elementos finitos. Nesta dissertação apresenta-se a utilização de um software de elementos finitos, o GEO5, para a resolução do problema de percolação numa barragem de seção bastante complexa, a Barragem Eng. Armando Ribeiro Gonçalves, que no final de sua construção sofreu ruptura do talude de montante da barragem central, devendo ser adequadamente monitorada. Por isso é importante verificar se o comportamento da barragem pode ser corretamente simulado pelo programa por estar em concordância com os resultados das leituras dos instrumentos instalados e se o mesmo pode prever futuras situações de risco de forma que possam ser contornadas. 

2013
Thèses
1
  • ZODINIO LAURISA MONTEIRO SAMPAIO
  • ANÁLISE DO COMPORTAMENTO MECÂNICO DE CONCRETOS PRODUZIDOS COM INCORPORAÇÃO DE CINZA DO BAGAÇO DA CANA-DE-AÇÚCAR DE VARIEDADES SP911049, RB92579 E SP816949


  • Leader : PAULO ALYSSON BRILHANTE FAHEINA DE SOUZA
  • MEMBRES DE LA BANQUE :
  • PAULO ALYSSON BRILHANTE FAHEINA DE SOUZA
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • EDILBERTO VITORINO DE BORJA
  • Data: 1 mars 2013


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  • Nas últimas décadas, notou-se um aumento gradativo de descarte de resíduo, bem como problemas oriundos da escassez de matérias-primas naturais no ramo da construção civil. Esses fatores vêm impulsionando a pesquisa universitária no âmbito de alternativas específicas e estudos sobre o aproveitamento de resíduos industriais como novos materiais, reduzindo o seu impacto ambiental. O concreto é o segundo produto mais consumido do mundo e a incorporação da Cinza do Bagaço da Cana-de-açúcar (CBC) a este material, pode apresentar soluções para o aproveitamento de subprodutos de outros setores, podendo-se obter um produto final com melhor desempenho.

    Este trabalho faz um relato acerca da inserção da CBC no concreto, visando à melhoria das suas propriedades mecânicas, como também à destinação adequada do subproduto da indústria sucroalcooleira. Esse estudo justifica-se pela importância de analisar e entender quais são os benefícios ocasionados às propriedades mecânicas dos concretos que são submetidos à inserção da cinza do bagaço da cana-de-açúcar. Outro aspecto se enfatiza no que se refere a estudos feitos a respeito dessa temática, é que ainda não abordam a influência das variedades de cana-de-açúcar utilizadas nessas propriedades. O objetivo geral dessa dissertação concentra-se em analisar o comportamento mecânico dos concretos que sofreram a adição de CBC de três diferentes espécies de cana-de-açúcar, mediante ensaios de consistência, resistência à compressão, porosidade total, absorção, índice de vazios e Microscopia Eletrônica de Varredura (MEV). Analisou-se separadamente a influência das variedades de cana-de-açúcar na resistência à compressão em função das idades de 7, 28 e 91 dias dos concretos, bem como a eficiência dessas adições. Foram confeccionados 13 corpos de prova para o concreto padrão e para cada teor de incorporação de CBC (10%, 20% e 30%) das três variedades coletadas, totalizando 130 amostras de concreto.  Foi empregado o traço 1:2:3 (cimento: areia: brita) em relação a massa do cimento e um fator água/cimento de 0,532. Os resultados mostraram que os concretos com adição de CBC, apresentaram uma redução de no mínimo 10% nas propriedades relacionadas a permeabilidade e um incremento na resistência à compressão de no mínimo 16% em relação ao concreto padrão.   De acordo com os resultados obtidos na presente pesquisa, concluiu-se, que a variedade da cana-de-açúcar, utilizada na produção das CBC, influenciou no comportamento mecânico dos concretos resultantes.

2
  • JANAINA SALUSTIO DA SILVA
  • ESTUDO DE CONCRETOS DE DIFERENTES RESISTÊNCIAS À COMPRESSÃO SUBMETIDOS A ALTAS TEMPERATURAS SEM E COM INCORPORAÇÃO DE FIBRAS DE POLITEREFTALATO DE ETILENO (PET)

  • Leader : MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • MEMBRES DE LA BANQUE :
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • JAQUELIGIA BRITO DA SILVA
  • EDILBERTO VITORINO DE BORJA
  • Data: 22 avr. 2013


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  • As estruturas de concreto armado são largamente utilizadas nas edificações em todo o mundo. Quando da ocorrência de incêndio em edificações, é consenso entre os estudiosos, que o concreto apresenta uma elevada resistência ao fogo, devido principalmente a sua baixa condutividade térmica. No entanto, isto não significa que esse material não seja afetado pela exposição a elevadas temperaturas. Redução de resistência à compressão e no módulo de elasticidade, alteração na coloração e aparecimento de fissuras, são alguns dos efeitos causados pela exposição térmica. No caso de concretos com resistênc ia mais elevada, ocorre ainda desplacamentos explosivos, expondo as armaduras ao fogo, e contribuindo assim para a redução da capacidade suporte do elemento estrutural. Diante do exposto, o presente trabalho tem por objetivo analisar como a resistência à compressão e a porosidade do concreto são afetadas quando submetido a elevadas temperaturas. Foram avaliados concretos de diferentes resistências, e ainda foi verificado se a incorporação de fibras de politereftalato de etileno (PET), em matriz de concreto, pode ser usada como alternativa a prevenção do lascamento. Os resultados indicaram que lascamentos explosivos acometem não somente concretos de alta resistência, como também o concreto convencional de média resistência, e que a faixa de temperatura para o qual o concreto começa a sofrer alterações expressivas em sua resistência fica entre 400 ºC e 600 ºC.

3
  • PAULO HENRIQUE ARAUJO BEZERRA
  • ANÁLISE DE ESTRUTURAS DE SUPERFÍCIE DELGADAS AXISSIMÉTRICAS VIA MÉTODO DOS ELEMENTOS FINITOS COM UTILIZAÇÃO DE ELEMENTO RETILÍNEO

  • Leader : SELMA HISSAE SHIMURA DA NOBREGA
  • MEMBRES DE LA BANQUE :
  • FERNANDA RODRIGUES MITTELBACH
  • SELMA HISSAE SHIMURA DA NOBREGA
  • ANGELO VIEIRA MENDONÇA
  • JOSE ANTÔNIO MARQUES CARRER
  • Data: 13 juin 2013


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  • O presente trabalho aborda a análise linear estruturas de superfície axissimétricas através do desenvolvimento e implementação de um código computacional baseado no Método dos Elementos Finitos. Inicialmente, as estruturas são estudadas de maneira isolada e, em seguida, compatibilizadas de modo a formar estruturas acopladas, como reservatórios e vasos de pressão. Exemplos de aplicação, com diferentes tipos de solicitação e condições de vinculação, são apresentados e os resultados obtidos pelo código desenvolvido são comparados a valores analíticos.

4
  • RAUL OMAR DE OLIVEIRA DANTAS
  • SUBSÍDIOS PARA O PROJETO DE ESTRUTURAS SISMO RESISTENTES.

  • Leader : PETRUS GORGONIO BULHOES DA NOBREGA
  • MEMBRES DE LA BANQUE :
  • JOAQUIM EDUARDO MOTA
  • JOEL ARAUJO DO NASCIMENTO NETO
  • PETRUS GORGONIO BULHOES DA NOBREGA
  • SELMA HISSAE SHIMURA DA NOBREGA
  • Data: 27 juin 2013


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  • Nesse trabalho são discutidos os critérios da norma NBR 15421:2006 para o desenvolvimento de um projeto de estruturas de concreto, considerando a análise sísmica. Inicialmente fez-se um levantamento dos conceitos fundamentais da engenharia sísmica, das principais ocorrências, globais e regionais, abordando-se a análise dos efeitos geradores de sismos, seus conceitos e particularidades. Apresentando posteriormente o detalhamento de todos os coeficientes sísmicos presentes na NBR 15421:2006 e comparou-se com as principais normas sísmicas internacionais. Foi desenvolvida uma comparação entre edifícios modelados através de espectro de resposta e através das forças horizontais sísmicas equivalentes, também se desenvolveu um estudo comparativo de uma edificação comercial submetido ao vento e a solicitações sísmicas. Destaca-se ainda a apresentação das principais recomendações e orientações técnicas em termos de concepção e detalhamento estrutural que devem servir de condicionantes para projetos atuais. Demonstra-se que os efeitos sísmicos incorrem na necessidade de detalhamentos específicos na estrutura, comprovando-se que a necessidade de uma abordagem diferenciada é essencial.

5
  • JOAO SERGIO SIMOES BEZERRA
  • Desenvolvimento de um Sistema de Planejamento, Gestão de Serviços e Controle de Custos em Obras de Construção Civil

  • Leader : JAQUELIGIA BRITO DA SILVA
  • MEMBRES DE LA BANQUE :
  • JAQUELIGIA BRITO DA SILVA
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • LEONARDO FLAMARION MARQUES CHAVES
  • CELSO LUIS EVANGELISTA DE OLIVEIRA
  • Data: 26 juil. 2013


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  • A crescente competitividade da indústria da construção civil, inserida em um ambiente econômico em que a oferta passou a ser superior à demanda, faz com que os preços de muitos produtos e serviços, sejam fortemente influenciados pelos processos de produção e pelos consumidores finais. Dessa forma, para se tornarem mais competitivas e presentes no mercado, as empresas construtoras estão buscando novas alternativas para redução e controle de custos, dos processos de produção e ferramentas que possibilitem o acompanhamento rigoroso do cronograma da obra, com o conseqüente cumprimento do prazo estabelecido com o cliente. Baseado neste panorama, a criação de ferramentas de controle, gestão de serviços e planejamento de obra, surge como uma oportunidade de investimento e uma área que pode promover grandes benefícios para as empresas construtoras. O objetivo geral deste trabalho é de apresentar um sistema de planejamento, gestão de serviços e controle de custos, que através de planilhas fornecerá informações referentes à fase de produção da obra, permitindo a visualização de possíveis irregularidades no planejamento e nos custos do empreendimento, possibilitando à empresa tomar medidas no sentido de alcançar as metas do empreendimento em questão, e corrigi-los quando necessário. O sistema desenvolvido foi utilizado em uma obra do mercado imobiliário do Rio Grande do Norte, e os resultados mostraram que o seu uso conjunto permitiu que a empresa construtora acompanhasse os seus resultados e tomasse ações preventivas e corretivas durante o processo produtivo, de forma eficiente e efetiva.

6
  • ERIKSON RICARDO MARQUES DE OLIVEIRA
  • Metodologia de implantação da construção enxuta: Estudo de caso

  • Leader : MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • MEMBRES DE LA BANQUE :
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • MARIANA RODRIGUES DE ALMEIDA
  • ALESSANDRO LUCAS DA SILVA
  • Data: 16 août 2013


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  • A construção civil brasileira, nos últimos anos, tem passado por mudanças como estabilidade da moeda, aumento da concorrência, escassez de mão de obra qualificada e aumento da importância da qualidade requerida pelo cliente, que fizeram que as empresas do setor procurassem soluções através de novas práticas de gestão buscando se tornarem mais eficientes. Uma alternativa é conhecida como Construção Enxuta (Lean Construction), que é derivada do Sistema Toyota de Produção. A Construção Enxuta visa reduzir a parcela de atividades que não agregam valor, aumentar o valor do produto através da consideração das necessidades do cliente, reduzir a variabilidade e tempo do ciclo de produção, simplificar o processo através da redução do número de passos ou partes, aumentar a flexibilidade na execução do produto e a transparência do processo, focar o controle no processo global, introduzir melhoria contínua no processo, manter um equilíbrio entre melhorias nos fluxos e nas conversões e ainda buscar aprender com as práticas adotadas pelas empresas concorrentes, contudo à indústria da construção civil é caracterizada por possuir atividade nômade, que empreende produto único, com custo elevado de produção e grande inércia para mudança comportamental, deste modo, torna-se difícil a implantação da filosofia da construção enxuta nas empresas. Neste sentido, o objetivo deste trabalho foi de criar uma metodologia de implantação dos princípios da Construção Enxuta, e ainda de elaborar documentos (procedimentos e formulários) que facilitassem este processo. A metodologia para implantação dos princípios da Construção Enxuta foi concebida utilizando a ferramenta 5W2H, e o processo de implantação foi dividido em quatro etapas, sendo a primeira com a finalidade de conhecer os produtos e/ou serviços gerados pela empresa, de qual o seu público alvo e ainda de entender de uma forma macro como é o funcionamento da organização; a segunda fase consistiu em desenhar a empresa através de organogramas tanto no setor administrativo como produtivo; a meta da terceira etapa foi de estabelecer quais os documentos (procedimentos e formulários) são necessários e de estabelecer as competências de cada colaborador; e a quarta fase foi destinada ao controle dos processos onde através do Planejamento Estratégico seriam definidos os objetivos da empresa com suas respectivas metas e indicadores com a finalidade de manter o sistema funcionando visando a melhoria contínua com foco no cliente. O estudo de caso foi realizado com uma empresa de porte médio com mais de 17 anos de atividade e certificada há quase 10 anos na ISO 9001 e nível A do PBQP-H, sendo realizada uma análise minuciosa nesta empresa com a finalidade de propor melhorias em seus processos, inclusive identificando quais os documentos deveriam ser elaborados com base nos princípios da construção enxuta. Ao longo do trabalho foram criados 10 documentos e modificados outros 19. Ao término deste trabalho a empresa estudo de caso encontrava-se em fase de implantação da presente metodologia.

7
  • EMANUEL HENRIQUE GOMES PAIVA
  • AVALIAÇÃO DO CONCRETO DE CIMENTO PORTLAND COM RESÍDUO DA PRODUÇÃO DE SCHEELITA EM SUBSTITUIÇÃO AO AGREGADO MIÚDO.

  • Leader : PAULO ALYSSON BRILHANTE FAHEINA DE SOUZA
  • MEMBRES DE LA BANQUE :
  • PAULO ALYSSON BRILHANTE FAHEINA DE SOUZA
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • SANDRA MARIA DE LIMA
  • Data: 23 août 2013


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  • A partir da década de 70, com a publicação do Manifesto Ambiental pela Conferência das Nações Unidas, realizada em Estocolmo na Suécia (1972); defender e melhorar o meio ambiente passou a fazer parte do nosso cotidiano.  Dessa forma, várias pesquisas surgiram, em diversos seguimentos, com o intuito do uso de resíduos. Alguns exemplos de resíduos incorporados ao concreto de cimento Portland são: cinza da casca de arroz; cinza do bagaço de cana-de-açúcar; pó-de-pedra; microsílica; borracha de pneu, entre outros. Este estudo utilizou o resíduo da indústria da mineração de Scheelita, com objetivo de avaliar a incorporação do resíduo à composição do concreto de cimento Portland, em substituição da areia. As porcentagens incorporadas do resíduo foram de 0% até 100%; com variação de 10%; sendo produzidos 11 traços de concreto na proporção 1:2:3:0,60; em peso. Foram avaliadas as seguintes características do concreto: abatimento; resistência à compressão axial; resistência à tração por compressão diametral; absorção de água; porosidade; e massa específica; tendo como base as normas da ABNT, através de ensaios realizados no Laboratório de Construção Civil da UFRN. O traço com acréscimo de 20% de resíduo de Scheelita foi o que obteve melhor desempenho, porém os resultados de resistência à compressão axial, principal característica do concreto, com idade de 91 dias, não obtiveram acréscimos. Dessa forma, a incorporação do resíduo de Scheelita ao concreto não apresentou ganhos às suas características.

8
  • JEFFERSSON FERNANDES DE LIMA
  • Avaliação da incorporação de cinzas de lodo de esgoto como adição mineral em concretos de cimento Portland

  • Leader : MARIA DEL PILAR DURANTE INGUNZA
  • MEMBRES DE LA BANQUE :
  • MARIA DEL PILAR DURANTE INGUNZA
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • PAULO ALYSSON BRILHANTE FAHEINA DE SOUZA
  • GLADIS CAMARINI
  • Data: 18 oct. 2013


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  • O desenvolvimento das grandes cidades tem gerado um dos maiores desafios ambientais enfrentados na atualidade, que é a gestão eficaz de resíduos sólidos. A grande variedade e quantidade dos resíduos produzidos diariamente, tem tornado a destinação ecologicamente correta e sustentável destes materiais cada vez mais difícil. Dentre os vários resíduos produzidos diariamente destacam-se os lodos oriundos de estações de tratamento de esgotos, denominados de lodos de esgoto, cuja destinação final segura tem sido discutida mundialmente em diversos estudos, tendo em vista que a tendência de geração deste tipo de resíduo tende a crescer com o aumento do saneamento das cidades. Uma forma amplamente difundida nos países desenvolvidos para destinação dos lodos de esgoto é a incineração destes materiais para posterior envio das cinzas geradas neste processo a aterros sanitários. Porém, tem-se estudado formas alternativas de disposição, destacando-se a utilização destas cinzas como adição mineral em concretos e argamassas de cimento Portland. Sabe-se que o desempenho de resíduos de incineração como adição mineral em matrizes cimentícias, depende em grande parte da capacidade de atuação destes materiais como elementos pozolânicos ou como fileres, podendo estas características serem influenciadas pela temperatura de queima ao qual estes resíduos foram submetidos. Neste sentido, verificou-se com esta pesquisa a influência da temperatura empregada na queima dos lodos sépticos no índice de atividade pozolânica (IAP) das cinzas geradas como resíduo deste processo, aqui denominadas de cinzas de lodo séptico (CLS), sendo em seguida, avaliadas as implicações técnicas e microestruturais da utilização deste resíduo em teores de 10%, 20% e 30% como adição mineral em concretos de cimento Portland. Os resultados obtidos demonstraram não haver alterações significativas no IAP das CLS em decorrência da temperatura utilizada durante o processo de queima dos lodos de esgoto. Além disso, verificou-se que embora a utilização das CLS tenham provocado diminuição da trabalhabilidade dos concretos para todos os teores de incorporação, estas melhoraram a resistência mecânica à compressão, o índice de vazios, a absorção de água e o comportamento microestrutural dos concretos contendo 10% e 20% de resíduo.

9
  • MANOEL FERNANDES DE NEGREIROS NETO
  • A CONSTRUÇÃO DA PONTE METÁLICA SOBRE O RIO POTENGI: ASPECTOS HISTÓRICOS, CONSTRUTIVOS E DE DURABILIDADE. NATAL/RN, BRASIL (1912-1916) - ESTUDO DE CASO.

  • Leader : JAQUELIGIA BRITO DA SILVA
  • MEMBRES DE LA BANQUE :
  • JAQUELIGIA BRITO DA SILVA
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • RICARDO NASCIMENTO FLORES SEVERO
  • Data: 28 nov. 2013


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  • RESUMO:

    A construção da ponte em treliça metálica sobre o rio Potengi em Natal, Estado do Rio Grande do Norte, entre os anos de 1912 e 1916, foi uma realização de obra além da engenharia brasileira da época. Quando o engenheiro João Proença recebe da então República Velha brasileira um contrato em nome de sua Companhia de Viação e Construções SA para empreender a Ponte sobre o Potengy, conforme o jornal O Paiz relatava na época, percebe-se a enorme tarefa a ser desenvolvida e contrata-se uma renomada empresa inglesa. Essa empresa inglesa nasceu na região berço das primeiras ferrovias, o Condado de Durham, mais precisamente na cidade de Darlington. A solução naqueles anos eram fundações em blocos de concreto armado e vãos em treliças metálicas. A construtora chamava-se Cleveland Bridge Engineering Company Co, e a ponte metálica era o símbolo da segunda revolução industrial. Exatamente nesses anos o engenheiro chefe e projetista da Cleveland Bridge era um francês chamado Georges-Camille Imbault, então responsável pelo projeto da ponte. O processo de tubulões a ar comprimido tinha acabado de ser desenvolvido pela construtora, e foi o método escolhido para as fundações em Natal. Segundo o projeto do engenheiro Imbault, suas bases deveriam ser apoiadas sobre o cascalho encontrado no leito do rio Potengi. Dentre diversos detalhes do processo construtivo da Ponte do Rio Potengi, foi constatada uma real dificuldade na implantação dos tubulões, na época conhecidos como cilindros de ar comprimidos, e também problemas estruturais durante a execução. No ano de 1914, a ponte foi concluída, sendo inaugurada somente em 1916. O presente trabalho tem como objetivo analisar historicamente e tecnicamente a Ponte sobre o Rio Potengi, ressaltando, primordialmente, o processo construtivo, as qualidades e características dos materiais utilizados e as propriedades tecnológicas, químicas, mineralógicas e microestruturais do cimento e do concreto empregados em sua construção.

10
  • ARTHUR GOMES DANTAS DE ARAUJO
  • Provas de carga estática com carregamento lateral em estacas hélice contínua e metálicas em areia

  • Leader : YURI DANIEL JATOBA COSTA
  • MEMBRES DE LA BANQUE :
  • YURI DANIEL JATOBA COSTA
  • CARINA MAIA LINS COSTA
  • MAURÍCIO MARTINES SALES
  • Data: 10 déc. 2013


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  • Um estudo experimental foi realizado para investigar o comportamento de estacas hélice contínua e estacas metálicas, com perfil H, cravadas submetidas a carregamentos laterais em solo arenoso. As estacas foram ensaiadas em duas áreas diferentes no mesmo local. Ambas as áreas eram compostas por um aterro superficial de 3 m de espessura de areia fina, seguidas de camadas naturais de areia fina a grossa. Os aterros diferenciam-se pela densidade relativa com que foram compactadas, 45% e 70%, respectivamente. Cada área recebeu um par idêntico de estacas hélice contínua e dois pares idênticos de estacas metálicas. Em cada par de estacas foi executada uma prova de carga estática. Neste trabalho, os resultados das provas de carga são apresentados e interpretados. Os coeficientes de reação horizontal do solo foram determinados através dos resultados das provas de carga e comparados com valores dos mesmos coeficientes determinados por correlações baseados no NSPT corrigido. Curvas p-y foram construídas para prever o comportamento de estacas submetidas a carregamentos horizontais. Os parâmetros necessários para modelagem das curvas p-y foram obtidos por retro-análise das curvas carga versus deslocamento horizontal obtida experimentalmente. Além disso, obtiveram-se valores de carga de ruptura e carga admissível horizontal, para métodos teóricos e baseados nas provas de carga, verificando sua validade.

11
  • FABIANA ALVES DOS SANTOS
  • AVALIAÇÃO DO DESEMPENHO DE UMA CORTINA DE ESTACAS ESPAÇADAS ATIRANTADA EM AREIA

  • Leader : YURI DANIEL JATOBA COSTA
  • MEMBRES DE LA BANQUE :
  • CARINA MAIA LINS COSTA
  • RENATO CUNHA
  • YURI DANIEL JATOBA COSTA
  • Data: 16 déc. 2013


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  • O presente trabalho apresenta um estudo sobre o comportamento de uma cortina de estacas escavadas ancorada por tirantes, projetada para a construção do subsolo de um edifício residencial multifamiliar, localizado na cidade de Natal/RN. A estrutura foi instrumentada a fim de se medirem os deslocamentos horizontais da cortina e a distribuição de cargas ao longo do bulbo dos tirantes. Os deslocamentos horizontais foram medidos através de inclinometria, enquanto que as cargas nos tirantes foram obtidas com uso de extensômetros elétricos de resistência, instalados em três pontos ao longo do trecho ancorado. As medições de deslocamento foram feitas após cada etapa de execução da cortina e após a conclusão da obra, ao passo que as medições de carga nos tirantes foram feitas durante os ensaios de recebimento, no momento da incorporação e também após a conclusão da obra. A partir dos dados de deslocamento foram obtidos dados de velocidade e aceleração da cortina. O deslocamento horizontal máximo da cortina chegou a 0,66% da profundidade máxima de escavação, em uma das seções instrumentadas. A distribuição da carga nos tirantes decresce exponencialmente ao longo do bulbo. Além disso, verificou-se que houve perda de carga nos tirantes ao longo do tempo, chegando a uma perda máxima de 50% da carga inicial, em um dos tirantes instrumentados. 

12
  • CARLOS DE SOUZA JUNIOR
  • ANÁLISE DA ESTABILIDADE DE FALÉSIAS NA ZONA COSTEIRA DE BAÍA FORMOSA/RN

  • Leader : OLAVO FRANCISCO DOS SANTOS JUNIOR
  • MEMBRES DE LA BANQUE :
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • ADA CRISTINA SCUDELARI
  • VENERANDO EUSTAQUIO AMARO
  • OSVALDO DE FREITAS NETO
  • Data: 20 déc. 2013


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  • As mudanças naturais e antrópicas que vêm ocorrendo na zona costeira em todo o mundo representam um dos maiores problemas para a sociedade neste século. Essa importância se torna mais evidente devido à elevada densidade das cidades litorâneas, à crescente especulação turístico-imobiliária dessas áreas e às alterações climáticas que tendem a desencadear e acelerar esses processos. Nesse contexto, percebe-se cada vez mais um aumento significativo dos problemas relacionados à erosão costeira e recuo de falésias no estado do Rio Grande do Norte. A área de estudo desta pesquisa localiza-se na zona costeira do município de Baía Formosa/RN, no litoral oriental-sul do Rio Grande do Norte, e possui uma extensão de cerca de 1200 m ao longo da praia do Porto. O objetivo principal deste trabalho é analisar a estabilidade dessas falésias, através de investigações de campo, ensaios e análises computacionais utilizando o Método dos Elementos Finitos e o Método de Bishop. Para atender aos objetivos deste trabalho, a área foi subdividida em quatro trechos, e foram aplicados checklists e também realizados ensaios de caracterização e de cisalhamento direto com materiais obtidos ao longo desses trechos. Os segmentos de falésia nessa zona costeira possuem alturas variando em torno de 4 m e 14 m e inclinações de aproximadamente 40º a 90º. Os solos constituintes das falésias foram classificados, em termos gerais, como areias argilosas ou siltosas e argilas arenosas, sendo os solos mais argilosos e variegados pertencentes à base da falésia. As análises de estabilidade mostraram que os fatores de segurança variaram, no trecho 01, de 2,38 a 6,06, no trecho 02, de 1,01 a 1,62, no trecho 03, de 1,29 a 1,78, e no trecho 04, de 0,83 a 2,48. Assim, os trechos 02 e 03, foram considerados como mais instáveis. Entretanto, pode-se considerar o trecho 03 como o mais crítico devido à ausência de estruturas de proteção costeira e à estreita faixa de praia. Fato que não ocorre no trecho 02, o qual possui uma extensa faixa de praia e é protegido por um muro de arrimo que restringe o acesso dos banhistas às áreas adjacentes do pé da falésia.

2012
Thèses
1
  • LARISSA DANTAS BENEVIDES

  • AVALIAÇÃO DO USO DO DCP EM AREIAS PARA CONTROLE DA CAPACIDADE DE CARGA EM FUNDAÇÕES DIRETAS E CONTROLE DE COMPACTAÇÃO DE ATERROS

     

     

  • Leader : CARINA MAIA LINS COSTA
  • MEMBRES DE LA BANQUE :
  • CARINA MAIA LINS COSTA
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • PAULO MÁRCIO FERNANDES VIANA
  • YURI DANIEL JATOBA COSTA
  • Data: 27 févr. 2012


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  • Este trabalho apresenta resultados de ensaios com o DCP realizados em campo e em laboratório com o objetivo de avaliar o uso do equipamento em areias para o controle da capacidade de carga em fundações diretas e compactação de aterros. No caso da análise de fundações diretas, os ensaios em laboratório foram realizados com o solo preparado em um cilindro metálico através do método da chuva de areia. Apesar dos resultados mostrarem a impossibilidade de reproduzir em laboratório as condições de campo verificou-se a possibilidade do uso do DCP no controle de execução de fundações diretas para a detecção de camadas menos resistentes. Na análise do aterro compactado o solo foi preparado numa caixa com diferentes densidades relativas através do uso de uma placa vibratória, simulando o procedimento de campo. Entre outras conclusões, os resultados mostraram o grande potencial de uso do DCP no controle da compactação de aterros com areia.

2
  • JULIO CESAR CAVALCANTE DAMASCENO
  • MODELOS PARA ANÁLISE E DIMENSIONAMENTO DE PAINÉIS DE ALVENARIA ESTRUTURAL

  • Leader : JOEL ARAUJO DO NASCIMENTO NETO
  • MEMBRES DE LA BANQUE :
  • JOEL ARAUJO DO NASCIMENTO NETO
  • PETRUS GORGONIO BULHOES DA NOBREGA
  • ROMILDE ALMEIDA OLIVEIRA
  • Data: 28 févr. 2012


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  • Os métodos utilizados para concepção e projeto de edifícios de alvenaria estrutural baseiam-se em normas nacionais e internacionais consolidadas. Para o cálculo de paredes de contraventamento à flexão levam-se em conta mecanismos similares aos adotados nas estruturas de concreto armado: diagrama Parábola-retângulo e manutenção da planicidade da seção transversal. Por outro lado, a prática de projeto de edifícios em alvenaria apresenta situações que não permitem o correto uso deste modelo devido à introdução de certas singularidades, principalmente: presença de aberturas de portas e janelas e grande desenvolvimento em planta das paredes. Consagrado no dimensionamento de estruturas em concreto armado, o método de bielas e tirantes tem sido vislumbrado para o dimensionamento de elementos de alvenaria estrutural em diversas situações: painéis sujeitos a cargas verticais concentradas, parcialmente distribuídas e painéis de contraventamento com e sem aberturas. Por outro lado, ainda são escassos na literatura estudos que apresentem subsídios para a completa definição do modelo, como parâmetros de resistência dos elementos e inclinações das bielas. Diante desses fatos, procurou-se neste trabalho definir critérios para a aplicação segura do método de bielas e tirantes na alvenaria estrutural, de forma a fornecer ao meio técnico um método alternativo de dimensionamento de suas paredes estruturais. Para tal foi necessário a realização de uma extensa modelagem numérica em elementos finitos de painéis de alvenaria. Essas análises permitiram a construção dos modelos de bielas e tirantes dos painéis, comparando as forças teóricas obtidas com este método com resultados de ensaios experimentais e outras metodologias de dimensionamento. Adicionalmente, analisou-se o efeito da ortotropia da alvenaria no comportamento de painéis de edifícios, no que se refere à rigidez e distribuição de forças horizontais.

3
  • FRANCISCO MATEUS GOMES LOPES
  • ESTUDO DO COMPORTAMENTO MECÂNICO DE AREIAS ARTIFICIALMENTE CIMENTADAS

  • Leader : OLAVO FRANCISCO DOS SANTOS JUNIOR
  • MEMBRES DE LA BANQUE :
  • BERNADETE RAGONI DANZIGER
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • RICARDO NASCIMENTO FLORES SEVERO
  • YURI DANIEL JATOBA COSTA
  • Data: 9 mars 2012


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  • Solos melhorados com adição de cimento têm sido bastante utilizados como alternativa na construção de diversos tipos de obras geotécnicas, quase sempre por apresentar vantagens econômicas e ambientais. Este trabalho apresenta um estudo sobre a utilização de cimento no melhoramento das propriedades mecânicas de solos arenosos característicos da região de Natal, coletados em dunas. Foram avaliados a influência do teor de cimento, do índice de vazios e da inundação e da tensão confinante. Corpos-de-prova moldados a partir de misturas de solo-cimento foram submetidos a ensaios de resistência à compressão simples e à compressão triaxial. Nas amostras as porcentagens de cimento foram variadas em 2,5%, 5% e 10%. O agente cimentante utilizado foi o Cimento Portland de Alta resistência inicial ( CP-V ARI), que promoveu agilidade ao procedimento experimental por apresentar um processo de cura mais rápido.Os índices de vazios utilizados variaram de 0,7 (mais compacto), 0,9 e 1,1(mais fofo). A caracterização indicou que o solo estudado pode ser considerado como uma areia pura. De uma forma geral, pode-se afirmar que quanto maior a quantidade de cimento adicionado à areia estudada, maior a sua resistência final. Da mesma forma, quanto mais compacto estiver esse solo, isto é, quanto menor o índice de vazios, mais resistente ele se apresentará. A tensão confinante tende a aumentar a resistência dos corpos de prova. Nos graus de cimentação adotados, a utilização de diferentes critérios de ruptura não alterou significativamente os parâmetros tensão-deformação para a areia estudada. Os valores de ângulo de atrito encontrados estavam dentro dos valores típicos para areias médias e compactas. A cimentação agiu na areia de modo a proporcionar um intercepto de coesão que aumentou com o incremento da cimentação. Nos ensaios de compressão triaxial, a areia com índice de vazios igual a 0,7 apresentou o comportamento esperado para uma areia compacta, enquanto o comportamento tensão deformação da mesma areia com índice de vazios de 0,9 tendeu ao esperado para a areia fofa.

4
  • JOHN GLENNEDY BEZERRA GURGEL
  • MODELAGEM NUMÉRICA DE ESTRUTURAS DE CONTENÇÃO ATIRANTADAS EM AREIA

  • Leader : YURI DANIEL JATOBA COSTA
  • MEMBRES DE LA BANQUE :
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • PAULO JOSÉ ROCHA DE ALBUQUERQUE
  • WILSON CARTAXO SOARES
  • YURI DANIEL JATOBA COSTA
  • Data: 2 juil. 2012


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  •  O presente trabalho apresenta um estudo numérico através do método dos elementos finitos (MEF) utilizando-se o aplicativo computacional Plaxis 2D, com o objetivo de verificar aspectos do comportamento de estruturas de contenção atirantadas em areia. As análises foram dirigidas ao desenvolvimento dos deslocamentos horizontais, das tensões horizontais e dos esforços internos (esforço cortante e momento fletor) durante o processo construtivo da estrutura. As simulações numéricas incluíram avaliações da inf luência do comprimento da ficha, do espaçamento horizontal entre os tirantes, da espessura da parede e do comprimento do trecho livre. O perfil de solo utilizado nas simulações numéricas é representativo de uma determinada região da Cidade  de Natal – RN, na qual são construídas com frequência contenções do tipo analisado no presente trabalho. Usou-se o modelo constitutivo de Mohr-Coulomb para simular o  comportamento do solo e o modelo elástico linear para simular o comportamento dos elementos estruturais. Os parâmetros de resistência do solo foram obtidos por meio de ensaios de cisalhamento direto. Já os parâmetros de deformabilidade foram obtidos através de correlações empíricas obtidas de resultados de ensaios SPT executados na região em estudo. Os resultados obtidos mostraram que variações no comprimento da ficha praticamente não influenciam o comportamento da estrutura, no âmbito dos parâmetros avaliados. Já o espaçamento horizontal entre os tirantes apresenta forte influência sobre essas grandezas. Verificou-se também que a espessura da parede apresenta considerável influência sobre os deslocamentos horizontais e sobre os esforços internos, porém, apresenta pouca influência sobre as tensões horizontais.

5
  • FELLIPE CESAR ANDRADE COSTA MELO
  • ANÁLISE DE ARGAMASSAS COM SUBSTITUIÇÃO PARCIAL DO CIMENTO PORTLAND POR CINZA RESIDUAL DE LENHA DE ALGAROBA


  • Leader : MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • MEMBRES DE LA BANQUE :
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • ANA CECILIA VIEIRA DA NOBREGA
  • ANDREZA KELLY COSTA NOBREGA
  • Data: 27 déc. 2012


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  • Com o aumento do seu consumo, o cimento se tornou rapidamente um dos insumos mais consumidos pela humanidade no último século. Isso desencadeou um aumento das emissões de CO2, uma vez que a produção do cimento libera na atmosfera grandes quantidades deste gás. Somando este fato ao crescente pensamento da preservação ambiental, passou-se a buscar alternativas ao cimento, na forma de resíduos, para complementar os seus derivados, sendo uma delas as cinzas. Este trabalho teve como objetivo analisar as propriedades, no estado fresco e endurecido, de argamassas com substituição parcial do cimento Portland pela cinza residual de lenha de algaroba (CRLA) produzida pelas olarias do Estado. A CRLA foi recolhida e peneirada, onde parte dela foi moída e caracterizada em comparação com a apenas peneirada, sendo caracterizadas quanto a sua composição química, granulometria, finura, massa específica, massa unitária e Índice de Atividade Pozolânica. Avaliou-se que a cinza não atua como pozolana e que ela moída pouco variou em relação a apenas peneirada, injustificando seu uso. Adotou-se para este trabalho dois traços, sendo 1:3 (cimento : areia fina) e 1:2:8 (cimento : cal : areia média), ambos em volume, usando-se como materiais a CRLA apenas peneirada, o cimento Portland CP II F-32, a cal hidratada CH-I, areia de rio e água da concessionária local. Para cada traço foram adotados percentuais de substituição parcial do cimento pela cinza, sendo eles 0% (referência), 5%, 7%, 10%, 12% e 15%. No estado fresco, as argamassas foram ensaiadas com relação ao seu índice de consistência e à densidade de massa. No estado endurecido, foram ensaiadas com relação à sua resistência à tração na flexão, à compressão e de aderência à tração, e à sua densidade de massa no estado endurecido. Elas foram também analisadas por microscopia eletrônica de varredura e por difração de raios X. Além disso, as argamassas foram classificadas conforme a NBR 13281 (2005). Os resultados encontrados mostraram que, até um teor de 5% de substituição e para ambos os traços, pode-se substituir o cimento pela cinza residual de lenha de algaroba sem comprometer as argamassas microestruturalmente e no seu estado fresco e endurecido.


6
  • KIEV LUIZ DE ARAUJO PEREIRA
  • ESTABILIZAÇÃO DE UM SOLO COM CIMENTO E CINZA DE LODO PARA USO EM PAVIMENTOS

  • Leader : MARIA DEL PILAR DURANTE INGUNZA
  • MEMBRES DE LA BANQUE :
  • GREGÓRIO LUÍS SILVA ARAÚJO
  • MARIA DEL PILAR DURANTE INGUNZA
  • MOACIR GUILHERMINO DA SILVA
  • OLAVO FRANCISCO DOS SANTOS JUNIOR
  • Data: 27 déc. 2012


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  • Este trabalho apresenta um estudo da estabilização química de um solo com cimento e a avaliação do uso de cinza de lodo como aditivo estabilizante, investigando o comportamento mecânico das misturas solo-cimento e solo-cimento-cinza para uso em base e sub-base de pavimentos rodoviários. Os materiais envolvidos no estudo foram: solo silte-areno argiloso, cimento Portland comum e lodo esgoto calcinado de uma lagoa anaeróbia. A metodologia envolveu o estudo dos materiais, com ensaios de caracterização geotécnica do solo e mecânica das misturas solo-cimento e solo-cimento-cinza de lodo (SCCLE). As moldagens dos corpos de prova para o ensaio de compactação do solo e solo-cimento foram nas energias (normal, intermediária e modificada) e os teores de cimento adicionados ao solo foram (0%, 3%, 6% e 9%), no qual para cada traço/energia foram moldados 3 cp´s, sendo nesta etapa confeccionados 36 cp´s. A adição em percentual do cimento ao solo foi feita em relação massa do solo seco. Com os pontos da umidade retirados da curva de compactação do solo na energia normal foram moldados 5 cp´s para o ensaio de CBR, o melhor resultado foi do cp com umidade próximo a da umidade ótima, seu valor foi 6,13% e com uma expansão de 0,02%. Foi verificado a partir dos resultados do ensaio de CBR do solo a necessidade de sua estabilização tendo em vista que para o uso em camadas de sub-base e base são exigidos valores mínimos de 20% e 80% respectivamente segundo a especificação do DNER – ES – 301/97. No estudo da estabilização do solo foi utilizada como referência a resistência mínima à compressão simples para base e sub-base que é de 21 kgf/cm² de acordo com o DNER – ES – 305/97. Os cp´s de solo-cimento foram compactados nas energias e teores de cimento acima citados. O traço T4I foi o escolhido para adição de cinza, composto por (91% de solo + 9% de cimento na energia intermediária), sua resistência foi de 22,61 kgf/cm², este valor lhe credenciou aos padrões de camadas de base e sub-base.  A adição cinza de lodo foi feita nos percentuais (5%, 10%, 20% e 30%), o percentual de cinza foi calculado em relação à massa do solo seco e sendo nesta fase moldados 12 cp´s. Foi observado incremento da RCS em todos os traços contendo a cinza, sendo mais satisfatório o traço T7I com um ganho de 25,87% de resistência em relação ao traço T4I de referência contendo solo-cimento. A partir do estudo de estabilização podemos inferir que o solo não é expansivo podendo ser usado em camadas de pavimentos após a estabilização com cimento, e a cinza de lodo pode ser usada como aditivo estabilizante, uma maneira de reduzir os custos com o cimento e diminuir a poluição com o descarte do resíduo no meio ambiente. A avaliação ambiental segundo as normas (10004 e 10005 ABNT) mostrou que a cinza não oferece risco ao meio ambiente, abrindo oportunidades para futuros estudos com a adição de cinzas nos diversos traços e energias que não foram analisados neste trabalho.

     

2011
Thèses
1
  • VERUSKA KELLY GOMES ROCHA AVELINO
  • ESTUDO DO COMPORTAMENTO NO ESTADO FRESCO E ENDURECIDO DO CONCRETO COM INCORPORAÇÃO DE RESÍDUO DE CORTE DE BOTÃO

  • Leader : PAULO ALYSSON BRILHANTE FAHEINA DE SOUZA
  • MEMBRES DE LA BANQUE :
  • PAULO ALYSSON BRILHANTE FAHEINA DE SOUZA
  • JAQUELIGIA BRITO DA SILVA
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • RICARDO PEIXOTO SUASSUNA DUTRA
  • Data: 21 juin 2011


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  • O presente trabalho objetivou avaliar a influência da incorporação do
    resíduo de corte de botão em poliéster-RCBP sobre a plasticidade e a
    resistência mecânica em concreto de cimento Portland. O RCBP utilizado na
    pesquisa originou-se do material descartado por uma empresa fabricante de
    botão localizada no município de Parnamirim/RN. Utilizou-se o resíduo,
    como carga no concreto, nas concentrações de 5 %, 10 %, 15 % e 20 %, em
    relação à massa do cimento. Também se preparou um concreto sem
    incorporação do RCBP que serviu como referência. Nos ensaios de
    resistência à compressão foram testados quatro corpos-de-prova para cada
    idade (3, 7 e 28 dias) e traço, enquanto que para os ensaios de
    resistência à tração na flexão foram testados dois corpos-de-prova para
    cada traço. Além disso, fez-se o Slump Test, com vistas a verificar a
    consistência do concreto. Notou-se uma tendência de redução da resistência
    à compressão e abatimento para todos os traços com incorporação do RCBP.
    Houve um aumento de resistência à tração na flexão, para os traços de 5 %
    e 10%, em relação ao concreto de referência. Na análise microestrutural,
    observou-se que o RCBP apresentou uma superfície irregular e porosa,
    justificando assim, o decréscimo do abatimento.

2
  • ILZENETE ANDRADE MENEZES
  • AVALIAÇÃO DE CONCRETO COM ADIÇÃO DE FIBRAS DE PET SUBMETIDO A ALTAS TEMPERATURAS

  • Leader : MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • MEMBRES DE LA BANQUE :
  • ANA CECILIA VIEIRA DA NOBREGA
  • ANDREZA KELLY COSTA NOBREGA
  • MARIA DAS VITORIAS VIEIRA ALMEIDA DE SA
  • Data: 28 déc. 2011


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  • O concreto ao longo dos séculos constituiu-se num elemento estrutural indispensável na construção civil, devido a sua relativa facilidade de moldagem, sua durabilidade diante das intempéries, seu baixo custo, sua menor necessidade de manutenção, se comparado a outros materiais, como o aço. No entanto, quando o concreto fica exposto às altas temperaturas tende a perder suas características mecânicas, podendo inclusive ocorrer perda de seção, que compromete a estabilidade e a resistência mecânica dos elementos estruturais. As patologias decorrentes da exposição á elevadas temperaturas vão desde as fissuras, estalos até lascamentos explosivos.Nos últimos tempos, a tecnologia do concreto está intimamente ligada ao estudo de sua microestrutura.O uso de fibras adicionadas ao concreto tem se revelado como solução para o incremento de resistência mecânica do concreto, pois atua diretamente na distribuição dos esforços que atuam na peça no âmbito da microestrutura. Neste trabalho foram usadas fibras de PET reciclado incorporado ao concreto convencional utilizado em obras para verificação de resistência mecânica dessa mistura ás elevadas temperaturas. Os corpos de prova dos concretos com adição de fibras de PET foram ensaiados após exposição ás temperaturas: ambiente, 100ºC, 200ºC, 300ºC, 400ºC, 600ºC e 900ºC. Verificou-se que o concreto perde de forma significativa resistência mecânica quando exposto a temperaturas maiores que 300ºC, no entanto o uso da fibra de PET pode retardar o risco de colapso de estruturas pela formação de uma rede de canais que facilitam a fuga do vapor d´água, reduzindo a poro-pressão no interior do elemento estrutural.

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