Programa de Pós-Graduação em Engenharia Civil
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Master Thesis Análise de recuo de falésias no litoral do Estado do Rio Grande do Norte(Universidade Federal do Rio Grande do Norte, 2018-07-30) Câmara, Michel Rodrigues; Scudelari, Ada Cristina; Matos, Maria de Fátima Alves de; ; ; ; Amaro, Venerando Eustáquio; ; Severo, Ricardo Nascimento Flores;On the Coast of the State of Rio Grande do Norte, Northeastern Brazil, coastal erosion generates several problems, especially in the municipality of Tibau do Sul, where the tourist movement and the intense real estate speculation cause several environmental conflicts. Geoprocessing techniques were utilized through Digital Image Processing and Geographic Information System in the multitemporal analysis through the DSAS (Digital Shoreline Analysis System) tool in a scale of 3 decades, using images of remote sensors of spatial resolution of 30 meters and 5 meters to identify the areas that had erosive retreat of cliffs in the coast of the State of Rio Grande do Norte, measuring the retreat and the characterization of these environments. Five areas with erosive retreats were highlighted in cliffs of up to 101.1 meters, putting at risk areas of heavy urban occupation, diverse infrastructures and access roads. Then, using the same method, a 1-year multitemporal analysis was performed using remote sensing images of 1-meter spatial resolution in the city of Tibau do Sul, identifying stretches that obtained erosive retreat of up to 1.99 meters. Later, for the identification and characterization of the erosive processes in the study area, the checklist adapted to the coastal features in the research area was used, that is, coast with cliffs elaborated by Braga (2005). Finally, a comparison was made of the information obtained in the checklist of the same author in his field visit in 2004 with the data obtained in the checklist at the present time, identifying the areas that are still in continuous process of coastal and / or pluvial erosion as the areas in which a balance in the dynamics was identified, remaining stable. In addition to other stretches that formerly presented only one type of main erosion and currently two major types of erosion. It was verified that the checklist is an adequate tool in the identification of coastal erosive processes and pluvial, organizing in an organized way the collection and analysis of the information regarding the area of action and characteristics that trigger coastal and rain erosion. Such information serves as a subsidy for coastal management in these coastal environments of the Rio Grande do Norte coast.Master Thesis Avaliação da influência das curvaturas e das transversinas na distribuição do momento fletor devido à carga móvel em pontes curvas de concreto armado(2019-06-17) Ribeiro, Valberllan Albuquerque; Silva Filho, José Neres da; ; ; Barros, Rodrigo; ; Luchi, Lorenzo Augusto Ruschi e;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 (diaphragm) 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.Master Thesis Análise da evolução costeira para as praias de Muriú e Jacumã, litoral oriental do Estado do Rio Grande do Norte, Nordeste do Brasil, por meio do DSAS e SMC-Brasil(2019-07-31) Prudêncio, Mattheus da Cunha; Scudelari, Ada Cristina; ; ; Neves, Cláudio Freitas; ; Souto, Michael Vandesteen Silva; ; Amaro, Venerando Eustáquio;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 Muriú and Jacumã 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 Muriú and Jacumã 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.Master Thesis Uso de geotêxteis não tecidos para o dessecamento de resíduos da operação de corte de rochas ornamentais(2019-07-30) Vasconcelos, Italo Andrade; França, Fagner Alexandre Nunes de; Scudelari, Ada Cristina; ; ; ; Araújo, André Luis Calado; ; Ingunza, Maria Del Pilar Durante;In the past years the production of ornamental rocks have been intensified at Brazil, 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.Master Thesis Estudo do desempenho térmico e mecânico em argamassas de revestimento com substituição do agregado natural pela vermiculita expandida(2019-12-09) Guilherme, Deize Daiane Pinto; Cabral, Kleber Cavalcanti; ; ; Lucena, Luciana de Figueiredo Lopes; ; Souza, Wendell Rossine Medeiros de;Interest in the thermal performance of buildings is increasingly common due to user requirements and improvements in the enforcement of performance standards, which set the minimum efficiency criteria for a building. We highlight the charges related to thermal behavior, because they impact on the construction, the environment and affect the comfort and costs to users. An alternative to solve this problem is to change the constituent materials of building systems, such as the use of lightweight aggregates with potential for thermal insulation. In this context, the objective of the present work is to analyze the thermal and mechanical performance of coating mortars with substitution of natural aggregate for expanded vermiculite. The experimental procedure began with the characterization of the materials and the production of mortars with a 1: 1: 6 volume trace (cement: lime: sand) with substitutions of 25, 30, 35, 40, 45 and 50% of natural sand by expanded vermiculite, then fresh tests (consistency, density and water retention), hardened tests (density, tensile and compressive strength, modulus of elasticity, capillary and dip absorption and adhesion resistance) and finally , the thermal tests with the KD2Pro appliance and the thermal performance, through a prototype simulating the incidence of heat in 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 void 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.Master Thesis Argamassas produzidas a partir da substituição do agregado miúdo pelo resíduo do beneficiamento da scheelita e da água de hidratação por manipueira(2019-11-29) Souza, Rayanderson Saraiva de; Acchar, Wilson; ; ; Nóbrega, Andreza Kelly Costa; ; Marques, Sheyla Karolina Justino; ; Silva, Vamberto Monteiro da;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.Master Thesis Análise numérica comparativa entre pontes integrais e convencionais de concreto armado sujeitas às ações indiretas de temperatura, retração e fluência(2019-10-11) Coutinho, Pedro Mitzcun; Silva Filho, José Neres da; ; ; Barros, Rodrigo; ; Santos, Sérgio Hampshire de Carvalho;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 forces 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 bridges 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 shrinkage and creep actions were analyzed separately from the thermal actions. 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.Master Thesis Método de realocação de custos por meio da análise de função em projetos da faixa 1 do PMCMV(2019-09-06) Melo, Luane Assunção Paiva; Melo, Reymard Sávio Sampaio de; ; ; Santos, Débora de Gois; ; Queiroz, Luiz Alessandro Pinheiro da Câmara de;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. Moreover, 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 a track 1 PMCMV project conceived in a concrete wall system. Design Science Research was the research method. It included conducting the study in five phases: Problem Awareness (Systematic Literature Review and identification of research gaps); Suggestion (proposition of the first artifact version, based on Moraes (2017), to integrate Function Analysis into the cost reallocation process in PMCMV track 1 designs); Development (artifact construction through its application in a PMCMV track 1 design); Evaluation (artifact verification through focus groups) and Conclusion (final considerations). As a main result, a method was generated. The important contribution is to provide a way to reallocate costs in the design phase 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.Master Thesis Instalação de geossintéticos em pavimentos flexíveis com CBUQ: danos de instalação(2019-06-27) Azevedo, Letícia Maria Macêdo de; França, Fagner Alexandre Nunes de; Amorim, Enio Fernandes; ; ; ; Costa, Carina Maia Lins; ; Correia, Natália de Souza;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.Master Thesis Desenvolvimento de agregados leves a partir de resíduo de scheelita, lodo de esgoto e cinza da casca do arroz(2019-10-30) Souza, Maelson Mendonça de; Anjos, Marcos Alyssandro Soares dos; Araújo, André Luis Calado; ; ; ; Amorim, Ênio Fernandes; ; Barbosa, Normando Perazzo;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, located in the state of Sao Paulo. 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 use of scheelite residue (RPS), sewage sludge (SS), and rice husk ash (RHA), replacing two distinct types of clay. 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. Specifically, we also sought 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.