PPCivAm - Mestrado em Engenharia Civil e Ambiental
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Master Thesis Variabilidade espacial das propriedades mecânicas de sedimentos da formação barreiras no leste da Paraíba e do Rio Grande do Norte(Universidade Federal do Rio Grande do Norte, 2026-02-09) Santos, Pedro Júlio Castro dos; Santos Júnior, Olavo Francisco dos; Ingunza, Maria Del Pilar Durante; https://orcid.org/0000-0001-6994-7559; http://lattes.cnpq.br/1925954531585024; https://orcid.org/0000-0001-7552-6646; http://lattes.cnpq.br/1573496204231636; http://lattes.cnpq.br/3243319103841125; Freitas Neto, Osvaldo de; https://orcid.org/0000-0001-9488-4123; http://lattes.cnpq.br/6335708403185496; Severo, Ricardo Nascimento Flores; http://lattes.cnpq.br/8346360266500368The Barreiras Formation represents one of the most significant geological units in the northern and eastern portions of northeastern Brazil and is widely used as support for foundations, slopes, and coastal cliffs. However, its well-known lithological and mineralogical heterogeneity results in high variability of geotechnical properties, posing challenges to the safe design of such structures. In this context, this study aimed to quantify the spatial variability of the mechanical properties of sediments from the Barreiras Formation in the eastern regions of the states of Paraíba and Rio Grande do Norte, Brazil, derived from distinct geotechnical and geomorphological settings, through the correlation between mineralogy, physicochemical properties, and mechanical behavior. The methodology comprised laboratory tests for physical characterization, chemical and mineralogical analyses, as well as compaction, one-dimensional consolidation, permeability, and consolidated undrained triaxial compression (CU) tests, applied to samples collected from four distinct areas and analyzed comparatively. Based on these tests, relationships between stress–strain behavior and the micro- and macrostructural characteristics of the materials were established. The results revealed significant differences in the mechanical behavior of the analyzed soils, mainly associated with variations in grain size distribution, fines content, and mineralogical composition. Materials with higher silt content and higher concentrations of iron oxides exhibited greater cohesion, lower permeability, and overconsolidated behavior, whereas soils with predominance of the sandy fraction showed higher permeability, lower shear strength, and greater compressibility. In some cases, a predominantly frictional behavior was observed, associated with high preconsolidation stresses and low compressibility, possibly related to depositional conditions and interaction processes between different geological materials. Overall, the results confirm that relatively subtle variations in texture and mineralogy, associated with spatial variability, may result in substantial differences in mechanical performance, directly impacting the safety and durability of geotechnical structures.Master Thesis Análise técnica da incorporação do resíduo do beneficiamento da scheelita: reciclagem profunda de pavimento in situ com estabilização granulométrica(Universidade Federal do Rio Grande do Norte, 2026-02-03) Rolemberg, George Luis Moraes; Ingunza, Maria Del Pilar Durante; Rodrigues, John Kennedy Guedes; https://orcid.org/0000-0003-0340-5567; http://lattes.cnpq.br/7834302744515283; https://orcid.org/0000-0001-6994-7559; http://lattes.cnpq.br/1925954531585024; https://orcid.org/0009-0003-9969-3096; http://lattes.cnpq.br/2263029510011284; Santos Júnior, Olavo Francisco dos; https://orcid.org/0000-0001-7552-6646; http://lattes.cnpq.br/1573496204231636; Amorim, Enio Fernandes; https://orcid.org/0000-0001-7386-3956; http://lattes.cnpq.br/3436413268425331Brazil has the road transport mode as its predominant one, accounting for about 60% of all active transport modes in the country. However, this large share does not reflect the quality of its highways. According to the latest survey by the National Confederation of Transport (CNT) (2025), most of the paved network shows defects, causing losses for those who use these roads. To correct pavement defects, several methods are employed, with Full Depht Reclamation (FDR) being one of the most commonly used due to its economic and sustainable advantages, as it allows the reuse of materials and eliminates the need for new inputs. Several studies have been conducted to analyze the feasibility of using waste and byproducts in civil engineering, and waste from scheelite beneficiation is one of them. The scheelite beneficiation process generates large volumes of waste that are disposed of in open areas, causing various environmental impacts. In this context, the present study aimed to analyze the feasibility of incorporating this mineral waste into the FDR process. Recycled mixtures were prepared by adding waste, Reclaimed Asphalt Pavement (RAP), and crushed stone to the base materials collected from km 51.16 and km 51.60 of the BR-427/RN highway, executing physical and mechanical tests like grain sizes, Atterberg Limits and Califórnia Bearing Ratio (CBR). The mixture composed of, Base + 50% RAP + 15% Crushed Stone 19 + 20% Waste, met all the physical and mechanical parameters required by the standard DNIT 141/2022 – ES. Resilient Modulus (MR) tests were also performed for mixture M2 at km 51.16 and km 51.60, yielding average values of 475 MPa and 354 MPa, respectively, exceeding the average value of 250 MPa for Crushed aggregate, a material commonly used in granular pavement layers. The regression models obtained for the materials showed a predominant influence of confining stress (σ₃) on MR values, consistent with their Unbound granular nature. A mechanistic analysis was additionally carried out considering pavement rehabilitation using a recycled base designed with mixture M2 at km 51.16. The performance of this solution was compared with that of an equivalent pavement structure in which the deteriorated base layer was replaced by Crushed aggregates. The results demonstrated that the pavement structure incorporating the recycled base with scheelite residue met all established failure criteria.Master Thesis Avaliação da erosão costeira e função protetiva de ecossistemas naturais em praias do litoral setentrional do Rio Grande do Norte, mediante geotecnologias e modelagens aplicadas à dinâmica hidrossedimentar(Universidade Federal do Rio Grande do Norte, 2025-12-05) Carvalho, Gabriel Dalla Rosa; Amaro, Venerando Eustáquio; http://lattes.cnpq.br/4215328958233942; http://lattes.cnpq.br/2512639153259931; Nagabe, Fabiane; https://orcid.org/0009-0001-6652-6959; http://lattes.cnpq.br/8553322039067421; Pinheiro, Lívian Rafaely de Santana Gomes; https://orcid.org/0000-0001-6606-8807; http://lattes.cnpq.br/6518933055394823; Matos, Maria de Fátima Alves de; https://orcid.org/0000-0002-2864-2027; http://lattes.cnpq.br/7230788237148341Coastal erosion represents one of the most critical manifestations of morphodynamic instability, exacerbated by increasing anthropogenic pressure and climate change in the South Equatorial Atlantic. On the northern coast of Rio Grande do Norte (RN), Northeastern Brazil, inadequate urban and tourism expansion has intensified these processes. This study aimed to characterize and quantitatively measure the erosive impact on the beaches of São Miguel do Gostoso and Touros, providing technical support for engineering projects and adaptive regional coastal management. The methodological approach integrated the characterization of meteooceanographic forcings, multitemporal and geostatistical analyses of erosion, and the assessment of coastal vulnerability by incorporating the protective ecosystem services of natural features. The research employed remote sensing data (LANDSAT/SENTINEL-2) processed in the Digital Shoreline Analysis System (DSAS) to analyze historical shoreline changes (1986–2023) and applied the Coastal Vulnerability Index using the Integrated Valuation of Environmental Services and Tradeoffs (InVEST) model. Additionally, the Coastal Modeling System (SMC-Brasil) was used for hydrodynamic and hydrosedimentary modeling. The results indicate a significant increase in the average shoreline mobility in the recent period (2014–2023), with intensified variation rates. In areas with greater anthropogenic influence, the mean erosion rate reached -14.55 m/year. Modeling revealed an increase in the mean wave energy flux beginning in the 1980s, as well as changes in the propagation vector of the wave climate. In critical sites, such as Monte Alegre beach, the longshore sediment transport was estimated at approximately -240,698.25 m³/year. It was found that dunes and sandy beach systems provide effective buffering and morphodynamic resilience, reducing erosion risks. The prognostic assessment indicates a scenario of severe risk for coastal developments, reinforcing that the conservation of these habitats is essential for the balance and resilience of the coastal zone, requiring integrated strategies and effective management measures.Master Thesis Influência da hidroxipropilmetilcelulose nas propriedades termomecânicas de argamassas leves com substituição da areia por pó de poliestireno expandido(Universidade Federal do Rio Grande do Norte, 2025-08-22) Costa, Luzartt Pereira Barroso; Cabral, Kleber Cavalcanti; http://lattes.cnpq.br/5276293780237926; Silva, Janaina Salustio da; Almeida, Maria das Vitórias VieiraThe growing demand for energy efficiency in the construction sector has stimulated the development of innovative materials, particularly coatings applied to building envelopes. In this context, the incorporation of expanded polystyrene (EPS) waste into mortars emerges as a sustainable alternative, as it not only mitigates the environmental impacts of improper disposal but also acts as a lightweight aggregate, reducing density and enhancing thermal and acoustic insulation due to its porous morphology. This study evaluated a reference mortar with a 1:3 mix ratio (cement:sand by volume), in which the sand was partially replaced by EPS powder at proportions of 10%, 20%, 30%, 40%, and 50%. To optimize mechanical and thermal performance, hydroxypropyl methylcellulose (HPMC) was added at 0.20% of the cement mass. The formulations were subjected to tests in both the fresh and hardened states, microstructural analyses using scanning electron microscopy (SEM), and assessments of thermal and insulation properties. The results indicated that EPS, due to its low density, hydrophobicity, and limited adhesion to the cement matrix, promoted void formation, which partially compromised mechanical strength but enhanced insulating performance. HPMC, by promoting the formation of fibrous structures and polymeric films, contributed to enhanced bond strength, sealing of branched capillary pores, and a more pronounced reduction in thermal transmittance, an effect associated with its ability to incorporate air into the cementitious matrix. Consequently, the mixture with 50% EPS and HPMC (A50H) exhibited the best performance among the compositions evaluated when compared to the reference mortar, achieving an 81.82% increase in bond strength, a 62.22% reduction in capillary water absorption, a 48.43% decrease in thermal conductivity, and a 113.35% improvement in thermal insulation capacity. Thus, the A50H mortar stands out as a promising alternative for coatings and sealing systems, combining high thermal insulation performance with the reuse of EPS waste, and emerging as a viable and sustainable solution for the construction industry.Master Thesis Estudo do comportamento geomecânico compactado e indeformado de um solo residual tropicais da formação Barreiras em Bananeiras/PB(Universidade Federal do Rio Grande do Norte, 2025-08-27) Lima Neto, Francisco Felinto de; Santos Júnior, Olavo Francisco dos; https://orcid.org/0000-0001-7552-6646; http://lattes.cnpq.br/1573496204231636; http://lattes.cnpq.br/4777764277624255; Ingunza, Maria Del Pilar Durante; https://orcid.org/0000-0001-6994-7559; http://lattes.cnpq.br/1925954531585024; Lira, Bruna Silveira; https://orcid.org/0000-0001-7690-3941; http://lattes.cnpq.br/3597179861030111The tropical residual soils derived from the Barreiras Formation, widely distributed along the Brazilian coastal region, have attracted increasing scientific interest since the early twentieth century. In this context, this study aimed to perform a geotechnical characterization of a soil profile from the Barreiras Formation located in Bananeiras, Paraíba, Brazil, evaluating the material in both its natural and compacted states, with emphasis on the influence of compaction on its mechanical behavior. The studied profile originated from a sandstone parent rock and comprises three distinct soil layers. Characterization involved particle size distribution, X-ray diffraction (XRD), X-ray fluorescence (XRF), Crumb Test, rigid-wall and flexible-wall permeability tests, suction, Standard Penetration Test (SPT), oedometer compression (in dry and inundated states), direct shear, and triaxial compression tests. The results indicated that the first layer (AM-01) is a low-compressibility sandy clay (CL), collapsible in the natural state and slightly expansive when compacted, without a clear peak strength in either condition, exhibiting friction angles of 33.9° and 33.1°, respectively, and showing an almost instantaneous collapse when undisturbed. The second layer (AM-02) is a low-compressibility sandy silt (ML), expansive in both states, presenting a peak strength only in the natural condition, with friction angles of 46.2° and 25.7°, and collapsing only under an applied stress of 188 kPa. The third layer (AM-03) is a low-compressibility clay (CL), which exhibited a peak strength in the natural state but not when compacted, with friction angles of 29.7° and 36.4°, respectively. The study confirmed the pronounced heterogeneity of Barreiras Formation soils in their natural condition, evidenced by contrasting behaviors such as the instantaneous collapse of AM-01 and the high strength and permeability of AM-02. Compaction, however, proved to be an effective geotechnical treatment, significantly mitigating volumetric instability and reducing hydraulic conductivity, making the soil more suitable for use in lining systems and geotechnical works. Although compaction may reduce strength in some cases due to the breakdown of natural cementation, it transforms the highly variable lateritic soil into a stable, low-permeability material suitable for engineering applications.Master Thesis Efeitos das mudanças climáticas na geração de escoamento superficial em bacia tropical urbanizada(Universidade Federal do Rio Grande do Norte, 2025-05-29) Souza, Rafael Araújo de; Medeiros, Joana Darc Freire de; http://lattes.cnpq.br/1359759456699671; http://lattes.cnpq.br/7357056722886433; Tavares, Jean Leite; http://lattes.cnpq.br/5264177368997967; Silva, Jonathan Mota da; https://orcid.org/0000-0001-9995-8451; http://lattes.cnpq.br/3379521354576211; Amaro, Venerando Eustáquio; http://lattes.cnpq.br/4215328958233942Climate change, coupled with unplanned urbanization, intensifies the severity of extreme precipitation events, overloading urban drainage systems and increasing flood risks in cities. In this context, this study evaluates the impacts of climate change on surface runoff generation in a peri-urban sub-basin (XVI.5) within the Pitimbu River Watershed, located in Natal, Brazil. Using the PCSWMM software, hydrological and hydraulic simulations were conducted based on historical precipitation data (1961–2010) and climate projections from the MIROC6 model for both current and future periods (2011–2100), under the SSP2-4.5 and SSP5-8.5 scenarios. The simulations addressed light, moderate, and extreme rainfall events. The results indicate a decrease in light and moderate rainfall under future scenarios, in contrast to an intensification of extreme events, which lead to an increase in peak discharge of up to 39.13% under the SSP5- 8.5 scenario. Highly urbanized sub-basins exhibited significantly higher runoff compared to vegetated areas with a strong correlation between imperviousness and runoff generation (R = 0.79–0.99). These findings underscore the combined influence of urbanization and climate change in overwhelming drainage infrastructure, highlighting the projected intensification of surface runoff and the growing vulnerability to urban flooding. The study emphasizes the need for adaptive water management strategies that incorporate climate projections into the planning and governance of tropical watersheds.Master Thesis Aplicação de hidróxido de cálcio como técnica de mitigação da eutrofização em águas de reservatórios do semiárido brasileiro(Universidade Federal do Rio Grande do Norte, 2025-04-09) Sousa, Iranilton Ferreira de; Attayde, José Luiz de; Becker, Vanessa; http://lattes.cnpq.br/4121209629385349; http://lattes.cnpq.br/2839295698436271; Brito, Fernanda Monicelli Câmara; http://lattes.cnpq.br/8616031843113917; Oliveira, José Neuciano Pinheiro de; http://lattes.cnpq.br/4920511661069792Eutrophication is the process of increased primary production caused by increased input of limiting nutrients and represents a serious threat to aquatic ecosystems. Mitigation of this environmental problem is a necessary action that must include the reduction of external and internal sources of nutrients. This study investigated the potential of hydrated lime used in construction as a phosphorus sorbent using water from four reservoirs in the Brazilian semiarid region, through microscale laboratory experiments, where a phosphorus gradient was developed with 7 theoretical concentrations (0, 100, 200, 300, 400, 500 and 600 mg.L-1) and simulated conditions found in reservoirs in the semiarid region of Rio Grande do Norte. The results demonstrated that hydrated lime presented 99% phosphorus removal in natural waters through P sorption and calcium phosphate precipitation, with maximum sorption capacity (qmax) of 176.1 mg.P.g-1 (Dourado), 160.6 mg.P.g-1 (Gargalheiras), 130.3 mg.P.g-1 (Boqueirão) and 111.5 mg.P.g-1 (Armando Ribeiro Gonçalves). In addition, hydrated lime proved to be effective in removing humic substances, contributing to improving water quality. Through linear regression analysis, it was evidenced that increasing hardness and humic substances can help increase the qmax of the sorbent material, while the presence of sulfate ions can reduce qmax. Furthermore, the application of lime increased the pH of the medium, a phenomenon that assists in the main mechanism of sorption of the material and nullifies the inhibitory effects of calcium phosphate precipitation caused by humic substances. However, this fact requires attention when applying this compound to natural waters. It is concluded that hydrated lime used in civil construction is a promising and low-cost alternative for controlling eutrophication in reservoirs.Master Thesis Impactos hidrológicos das mudanças climáticas no semiárido: balanço de água no sistema hídrico Armando Ribeiro Gonçalves(Universidade Federal do Rio Grande do Norte, 2025-06-30) Teixeira, Heloisa Bezerra Varela; Silva, Jonathan Mota da; Attayde, José Luiz de; http://lattes.cnpq.br/4121209629385349; https://orcid.org/0000-0001-9995-8451; http://lattes.cnpq.br/3379521354576211; http://lattes.cnpq.br/2229629725451835; Silva, Fabrício Daniel dos Santos; https://orcid.org/0000-0002-3185-6413; http://lattes.cnpq.br/9324908747974694; Saad, Sandra Isay; https://orcid.org/0000-0002-4380-3175; http://lattes.cnpq.br/0103102694865890The semi-arid region of Northeastern Brazil is considerably vulnerable to the effects of climate change, with projections indicating an increased frequency of droughts and reductions in streamflow in its main rivers. Such changes may compromise the storage and regulation capacity of reservoirs, directly impacting water security in the region. This study aims to evaluate the water storage in the Armando Ribeiro Gonçalves (ARG) reservoir system, located in the Piancó-Piranhas-Açu River Basin, under future climate scenarios. To this end, climate and hydrological patterns of the system under recent climate conditions were analyzed, as well as projected changes in precipitation and evaporation within the ARG's catchment area, and the volume of water stored in the reservoir under those conditions. An integrated modeling approach was adopted, combining the SMAP hydrological model and a water balance model, applied to the SSP2-4.5 and SSP5-8.5 climate scenarios from the MIROC6 global climate model for the 2030–2059 horizon. The hydrological model was calibrated and validated using data from two fluviometric stations, the one closest to the reservoir providing the best simulation of local hydrological conditions. This result highlights that considering regional hydroclimatic characteristics can overcome the calibration challenges posed by flow regulation. The climate projections adequately simulated the seasonality of observed variables under recent climate (1990–2014), particularly precipitation and evaporation. The results indicate significant impacts of climate change on the reservoir’s storage and flow regulation capacity. The adopted methodology proved effective in supporting the planning and integrated management of water resources in the Piancó-Piranhas-Açu River Basin under future climate change scenarios.Master Thesis Influência da Diatomita nas propriedades de argamassa à base de cal para restauro(Universidade Federal do Rio Grande do Norte, 2025-04-04) Andrade, Sandro Ricardo da Silva; Sá, Maria das Vitórias Vieira Almeida de; Souza, Paulo Alysson Brilhante Faheina de; http://lattes.cnpq.br/2173551172181329; https://orcid.org/0000-0002-8324-7599; http://lattes.cnpq.br/7590200701773198; https://orcid.org/0009-0006-4773-1582; http://lattes.cnpq.br/2166781761573277; Cabral, Kleber Cavalcanti; https://orcid.org/0000-0001-7502-3002; http://lattes.cnpq.br/8387906402114241; Sousa, Adla Kellen Dionisio; https://orcid.org/0000-0002-4830-9803; http://lattes.cnpq.br/0641752587053504In recent years, the demand for conservation and rehabilitation services in historic buildings has increased. This is necessary, as preserving historic buildings is an important step in safeguarding a people's culture, identity and memories as a alive document. These interventions are often carried out with changes to materials and construction processes that have not always contributed to improving the state of conservation of historic buildings. With the main objective of evaluating the influence of diatomite on the physical, chemical and mechanical properties of lime-based mortars for the restoration of historic buildings, 4 (four) lime and sand-based mortar mixes (1:2, 1:4, 1:6 and 1:8) were selected, which are the most commonly found in historic buildings around the world. Diatomite was then incorporated, replacing hydrated lime in mass percentages of 10% and 20% in each of these four reference mixtures. The physical-mechanical characterization of the restoration mortar specimens was carried out at 28 and 90 days of age The results of the tests performed show an increase in the mechanical performance of the mortars with the incorporation of diatomite, reaching an average increase of 2.2 times in the axial compression resistance when 20% of diatomite was incorporated. Tests were also carried out with phenolphthalein at 150 days of age, revealing total carbonation of the samples in the reference traces Ref. - 1:8 and T20% - 1:8. Finishing the tests with durability assessment in 2 (two) scenarios, the first scenario being the test specimens exposed to 10 (ten) wetting/drying cycles with a saline solution (water + NaCl) and another with only drinking water (free of salts). The results of the analysis of the test specimens in saline solution showed surface wear from the mixtures with a binder-aggregate ratio of 1:6 onwards, both in the mortar samples without diatomite and in the samples with diatomite. Being the mix with the greatest surface damage and mass loss, the reference mix 1:8 followed by the mix 1:8 with 20% diatomite. In the scenario of immersion cycles in saltfree water, there was no aesthetic damage to the samples, nor was there any wear causing significant mass loss. Therefore, it can be concluded that the incorporation of diatomite brought gains in mechanical performance, but did not influence the increase in durability.Master Thesis Índice para mapeamento de áreas prioritárias para o monitoramento de pressão sonora de Parques Eólicos(Universidade Federal do Rio Grande do Norte, 2025-03-07) Santos, Geraldo Braz Silva; Silva, Hérika Cavalcante Dantas da; http://lattes.cnpq.br/7724097005059203; https://orcid.org/0000-0002-2311-8760; http://lattes.cnpq.br/6789696390336915; Rocha Júnior, Carlos Alberto Nascimento da; Carvalho, Rodrigo Guimarães de; Santos, Sandra RufinoThe noise from the operation of wind farms is one of the main concerns of surrounding populations, potentially causing adverse impacts on health and wellbeing. The noise impact depends on several variables, such as the distance to the receptor area, the characteristics of the turbine, and the speed and direction of the wind. In Brazil, the lack of legislation defining a minimum distance between populated areas and wind turbines may contribute to the exposure of inhabited areas to the noise from wind farm operations. With the large number of wind farms in operation, it is necessary to develop methodologies that identify, quantify, and assess which areas have the greatest need for monitoring potential noise impacts. Therefore, the objective of this study is to propose an index for mapping priority areas for monitoring noise pressure from wind farms. Using spatial analysis techniques, data on the exposure of potential receptors to noise from operating wind farms was obtained. The proposed index was built from seven individual indicators that, when weighted, allowed for the classification of areas according to their level of criticality. The results indicated that 10% of the operating wind turbines have receptors within the adopted noise influence area (400 m), with a total of 1,882 receptors. Regarding monitoring priority classes, 23 turbines were classified as “Very High,” 86 as “High,” 127 as “Medium,” and 81 as “Low.” The proposed index proved to be an effective tool for socioenvironmental management.Master Thesis Análise do comportamento mecânico de misturas de solos lateríticos e resíduo asfáltico para uso em camadas de pavimentos(Universidade Federal do Rio Grande do Norte, 2025-02-26) Silva, Phillipy Johny Lindolfo da; Amorim, Enio Fernandes; Rodrigues, John Kennedy Guedes; https://orcid.org/0000-0003-0340-5567; http://lattes.cnpq.br/7834302744515283; https://orcid.org/0000-0001-7386-3956; http://lattes.cnpq.br/3436413268425331; https://orcid.org/0000-0002-3214-1786; http://lattes.cnpq.br/4102821194591892; Freitas Neto, Osvaldo de; https://orcid.org/0000-0001-9488-4123; http://lattes.cnpq.br/6335708403185496; Marchezini, Silvana Fava; http://lattes.cnpq.br/4209742476821617The analysis of the mechanical behavior of soils and alternative materials for pavements has been widely studied due to the need for sustainable and economically viable solutions in transportation engineering. This study investigates the feasibility of using Reclaimed Asphalt Pavement (RAP), a byproduct of asphalt concrete production, in the stabilization of lateritic granular soils from Rio Grande do Norte for application in base and sub-base layers of flexible pavements. The samples were classified according to the MCT (Miniature, Compacted, Tropical) system and the Universal Methodology for Lateritic Soil Classification. The mechanical characterization involved repeated load triaxial tests to determine the resilient modulus (MR) and permanent deformation (PD), considering natural soils and mixtures with 10% and 20% RAP, as well as chemical stabilization with 2% cement. The results indicated that the incorporation of RAP improved the resilient response, increasing structural stiffness and reducing the accumulation of plastic deformations. Cement stabilization enhanced these effects, doubling the MR values and mitigating progressive deformations. The influence of confining stress was crucial in increasing the stiffness of the stabilized mixtures, while deviator stress significantly influenced the progression of permanent deformation, indicating higher structural resistance in mixtures with 10% RAP and cement, evaluated after seven days of curing. The applied models showed determination coefficients (R²) above 0.90, demonstrating a strong correlation between mechanical parameters and the obtained adjustments. Computational analyses performed using the MeDiNa software confirmed the structural feasibility of the evaluated mixtures under different traffic conditions, highlighting improvements in fatigue resistance and lower susceptibility to permanent deformation accumulation over time. The results contribute to a better understanding of the influence of lateritic granular soil stabilization with asphalt residues, providing guidelines for future applications in road infrastructure. It is concluded that the combination of RAP and chemical stabilization represents a sustainable and efficient alternative for pavement construction, reducing the need for natural aggregate extraction and promoting the reuse of asphalt industry residues.Master Thesis Influência da adição de um subproduto da produção de sal (carago) e do tempo de cura nas propriedades mecânicas de um solo expansivo da Cidade de Mossoró/RN(Universidade Federal do Rio Grande do Norte, 2025-02-27) Oliveira Júnior, Afrânio Pereira de; Freitas Neto, Osvaldo de; https://orcid.org/0000-0001-9488-4123; http://lattes.cnpq.br/6335708403185496; http://lattes.cnpq.br/9899636489322112; Santos Júnior, Olavo Francisco dos; Severo, Ricardo Nascimento FloresExpansive soils are found in various parts of the world. Their main characteristic is the volumetric variation due to the variation in moisture content. This is due to the presence of expansive clay minerals in the clay fraction of the soil. These volume variations cause damage to engineering works, which can range from small cracks to total structural compromise. These soils can be stabilized by adding materials that react with the clay and reduce or eliminate expansion. This research aimed to evaluate the influence of the addition of carago on the properties of expansibility and shear strength of an expansive soil in the city of Mossoró, in the state of Rio Grande do Norte (RN). For this purpose, geotechnical characterization, compaction, free expansion, expansion stress and direct shear tests were performed on soil mixtures with the addition of 5% and 10% carago. Regarding the influence of the addition of carago in the soil, it was possible to conclude that all samples with 10% carago showed a reduction in free expansion in relation to samples of pure soil, with emphasis on the 25% reduction in samples with 7 days of wet curing, in relation to samples of pure soil with the same time and type of curing. There was an increase in the expansion stress in all samples with carago subjected to dry curing in relation to pure soil, with the exception of the sample with 10% carago and no curing, which presented a value equal to that of pure soil. There was an increase in cohesion in all samples with the addition of carago in relation to samples with pure soil, with emphasis on the 624% increase in the sample with 10% carago and 7 days of dry curing. Regarding the curing time of the samples, it was concluded that the longer dry curing time increased the free expansion and expansion stress in all samples subjected to this type of curing. The longer wet curing time reduced cohesion, this indicates that the carago may lose cementing action over time; for lower percentages this occurs more quickly.Master Thesis Avaliação da aplicabilidade de cinzas de fundo de resíduos de serviço de saúde para uso em cobertura final de aterros sanitários(Universidade Federal do Rio Grande do Norte, 2023-11-30) Guerra, Nicolle Regina Cristino Belfort; Ingunza, Maria Del Pilar Durante; França, Fagner Alexandre Nunes de; https://orcid.org/0000-0001-6994-7559; http://lattes.cnpq.br/1925954531585024; http://lattes.cnpq.br/1794622631743171; Freitas Neto, Osvaldo de; Severo, Ricardo Nascimento FloresIn alignment with the global trend of comprehensive waste mapping and identification before final disposal, and the practice of landfilling only after exploring all potential avenues for reuse, coupled with recent amendments in Brazilian legislation mandating thorough awareness of by-products emanating from production processes for consideration of alternative destinations prior to landfilling, this study proposes the judicious application of incineration ash derived from Healthcare Waste (HW) as a functional component in the final cover of landfills. The objective is to achieve a purposeful and effective disposal. To realize this objective, the study delves into the properties of bottom ash resulting from the incineration of HW at a facility in Paraíba. The aim is to evaluate its suitability for deployment in impermeable barrier layers. The experimental program encompasses geotechnical analyses, as well as assessments of chemical and mineralogical composition, to ascertain whether the material possesses the requisite characteristics for the intended use. Mixtures were prepared by combining the soil typically employed in the final cover of landfills (S) with varying proportions of HW ash (C), with substitutions expressed in terms of mass percentage (S95C5, S92.5C7.5, S90C10, S85C15, S80C20). The results revealed that the primary chemical constituents of the ash are Calcium and Chlorine, accompanied by the presence of fibrous particles composed of Carbon. Physically, the ash exhibits similarities to municipal solid waste ash, commonly classified as sand, with specific gravity of solids lower than typical sand values. The outcomes of compaction tests on soil and mixtures demonstrated a slight variability in optimum moisture content, ranging between 8.3% and 11.9%, and maximum dry density, varying from 1.8 to 2.1 g/cm³. In contrast, the ash curve displayed an optimum moisture content of 37.2% and maximum dry density of 1.01 g/cm³. Importantly, all mixtures exhibited a saturated permeability coefficient in the order of 10-7 m/s, closely aligning with the recommended values of hydraulic conductivity coefficient found in the literature. This substantiates their suitability for the proposed application.Master Thesis Influência dos constituintes do LC³ em pastas para cimentação de poços de petróleo(Universidade Federal do Rio Grande do Norte, 2024-05-31) Santos, Lilian Alaide Souza; Nóbrega, Ana Cecilia Vieira da; Freitas, Júlio Cézar de Oliveira; https://orcid.org/0000-0003-1118-1911; http://lattes.cnpq.br/3109732203611868; http://lattes.cnpq.br/5070958575939550; Moraes, Edgar Perin; Santiago, Rodrigo César; Braga, Glauco SoaresThe use of blends with lower clinker content in their composition (Limestone Calcined Clay Cement – LC³) has gained prominence in recent years, primarily due to the significant CO2 emissions associated with clinker production in the cement industry. Therefore, developing blends with reduced clinker content, like Portland cement and utilizing abundant and naturally available materials, is innovative as it becomes both environmentally and economically viable. This study developed slurries intended for oil well cementing, using LC³ blends with varying cement percentages. The influence of LC³ components, namely Portland Class G cement, metakaolin, dolomitic limestone filler, and alpha gypsum, was evaluated via Response Surface Methodology for slurries with a specific gravity of 14.2 lb/gal (1.66 g/cm³). Additionally, the impact of LC³ slurry materials on essential oil well cementing properties (rheological parameters and compressive strength at 8 hours, 24 hours, and 7 days of curing) were studied. After a detailed analysis of these properties, along with a literature review, an optimized and promising LC³ slurry was developed. However, its high plastic viscosity and final gel strength require corrective additives. The optimized LC³ blend (55% Portland Class G cement, 23% metakaolin, 16% dolomitic limestone filler, and 6% gypsum) produced an LC³ slurry with consistencies of 23 Bc and 20 Bc at 27 °C and 52 °C, respectively, and a setting time of 5 hours. The porosity of this slurry at 24 hours of curing was 55.0525% of its volume, significantly reducing at 7 and 28 days to 9.0511% and 3.3306%, respectively. The permeability of the slurry at 24 hours of curing was 7.4106 mD, decreasing to 0.0051 mD and 0.0026 mD at 7 and 28 days, respectively. Uniaxial compressive strength tests performed on 11 LC³ slurries, derived from the experimental design, demonstrated their satisfactory and promising nature. The lowest compressive strengths for these slurries were 7.79 MPa and 17.04 MPa, while the highest were 10.68 MPa and 23.68 MPa, at 24 hours and 7 days, respectively. These results confirm that LC³ slurry can potentially be applicable for oil well cementing in the future.Master Thesis Efeito anti-regressão de sílicas alternativas na cimentação de poços de petróleo a alta temperatura e alta pressão(Universidade Federal do Rio Grande do Norte, 2024-10-25) Pereira, Fábio; Nóbrega, Ana Cecilia Vieira da; https://orcid.org/0000-0003-1118-1911; http://lattes.cnpq.br/3109732203611868; Costa, Bruno Leonardo de Sena; Braga, Glauco SoaresWell cementing in high-temperature scenarios is a critical process in well construction. In high-temperature and high-pressure environments, challenges increase significantly because the cement must withstand elevated temperatures without compromising its stability and mechanical properties. This study aimed to evaluate the contribution of different replacement percentages in the combined use of two silica-rich (SiO2) waste materials: Quartz-Aluminous Sand (QAS) and Biomass Thermal Treatment Residue (BTTR), in comparison to a reference paste with Crystalline Silica, a typical mineral additive used in cementing operations in hightemperature environments. Specimens were cast according to international standards and cured directly in a curing chamber at 180 °C and 3000 Psi (20 MPa) for 7, 14, and 28 days. After these curing periods, the specimens underwent uniaxial compressive strength testing to evaluate their mechanical strength. Samples were collected for microstructural analyses, including Xray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM), as well as qualitative analyses by energy dispersive spectroscopy (EDS). The results showed that the reference paste with 35% Crystalline Silica replacement preferentially formed the Xonotlite phase at all three curing ages. The ternary pastes, with 50% combined replacement of residues from industrial mortar production and biomass thermal treatment, preferentially formed the Tobermorite phase at all curing ages; the presence of the Tobermorite phase is a positive indicator for the long-term stabilization of ternary cementitious systems. Systems using the combined waste materials rich in silica (SiO2), with an AQAAQA/RTTB ratio below one, achieved 87% of the compressive strength when compared to the Crystalline Silica system. These aspects can provide a solid basis for optimizing formulations used in wells.Master Thesis Potencial de escoamento superficial, de erosão acelerada e de poluição difusa na Bacia Hidrográfica do Rio Potengi - RN(Universidade Federal do Rio Grande do Norte, 2025-01-24) Ramalho, José Arthur do Nascimento; Costa, Carlos Wilmer; Cunha, Karina Patricia Vieira da; http://lattes.cnpq.br/1431958912117459; https://orcid.org/0000-0002-3148-0030; http://lattes.cnpq.br/6913631503818679; http://lattes.cnpq.br/5026001910585123; Santos Júnior, Olavo Francisco dos; Lollo, José Augusto DiThis study aimed to delineate and analyze the potential for surface runoff, accelerated erosion, and diffuse pollution in the Potengi River Basin (PRB), focusing on the identification of priority areas for conservation and restoration. An integrated Multi-Criteria Decision Analysis (MCDA) methodology was applied in a GIS environment, which incorporated geo-environmental attributes such as geological units, slope, thickness of unconsolidated materials, permeability, drainage density, surface storage features, landforms, rainfall, land use and cover, erodibility, soil texture, and phosphorus and organic matter content. The results indicated that the PRB is predominantly characterized by low and moderate surface runoff potentials (98.44% of the area), although approximately 60.91% of the area presents a high risk of accelerated erosion due to a combination of factors such as steep slopes and highly erodible sandy soils. About 38.96% of the watershed area showed high to very high diffuse pollution potential, highlighting water vulnerability and the need for integrated management strategies, such as the recovery of riparian vegetation. The analyses underscore the importance of actions to mitigate the impacts of erosion and pollution, promoting environmental sustainability in the PRB. Additionally, the methodology proved effective in characterizing these processes, offering an approach that is replicable in other watersheds, especially in semi-arid regions where environmental pressures are intense and natural vulnerability is high. Methodological innovations in obtaining some of these attributes, such as for storage features, drainage density, and erodibility, as well as using sand and clay fractions to address soil texture in map algebra, enhanced cartographic representation, providing a more precise and grounded spatial analysis.Master Thesis Avaliação da redução da expansividade de solo estabilizado com resíduo de beneficiamento de rochas ornamentais(Universidade Federal do Rio Grande do Norte, 2024-09-30) Braz, Raabi Inarair Ferreira; Ingunza, Maria Del Pilar Durante; Bezerra, John Eloi; https://orcid.org/0000-0001-6994-7559; http://lattes.cnpq.br/1925954531585024; http://lattes.cnpq.br/4526304179354720; França, Fagner Alexandre Nunes de; https://orcid.org/0000-0002-8113-622X; http://lattes.cnpq.br/6854485206744906; Severo, Ricardo Nascimento FloresExpansive soils exhibit volumetric instability when exposed to variations in moisture content. Understanding the mechanisms of soil expansion and identifying effective stabilization techniques are critical for minimizing structural and economic losses in civil construction. Among the various stabilization methods, chemical stabilization is particularly notable, typically involving the addition of Portland cement or hydrated lime. However, the high costs and environmental impact associated with producing these materials have prompted researchers to explore alternative stabilizers, including industrial solid waste, which is often produced in large quantities and inadequately disposed of. This study aims to analyze the volumetric stabilization of expansive soil using ornamental rock processing waste, evaluating improvements in the soil's mechanical, hydraulic, and deformability properties. Expansive soil samples were collected in Mossoró, RN, and stabilized by incorporating ornamental rock processing waste at replacement rates of 11.10%, 25.00%, and 42.86% of the total soil mass. Preliminary analyses of the expansive soil, waste material, and soil-waste mixtures included particle size distribution (sieving and sedimentation), Atterberg limits, and specific gravity tests. Chemical characterization was conducted using X-ray fluorescence (XRF) and X-ray diffraction (XRD). Finally, mechanical behavior was assessed through consolidation tests to determine expansion pressure. The results indicate that incorporating ornamental rock processing waste into expansive soil shows significant potential for mitigating soil expansivity. The reduction in clay content and the addition of non-plastic materials improved the mechanical properties of the soil, enhancing its strength and suitability for civil engineering applications. This approach presents an effective and environmentally sustainable solution for managing expansive soils.Master Thesis Caracterização geomecânica de um solo residual compactado de gabro no Nordeste Brasileiro(Universidade Federal do Rio Grande do Norte, 2024-09-30) Campos, Pedro Henrique Silva de; Santos Júnior, Olavo Francisco dos; https://orcid.org/0000-0001-7552-6646; http://lattes.cnpq.br/1573496204231636; https://orcid.org/0009-0009-4549-6883; http://lattes.cnpq.br/1877054299138280; Freitas Neto, Osvaldo de; https://orcid.org/0000-0001-9488-4123; http://lattes.cnpq.br/6335708403185496; Severo, Ricardo Nascimento FloresThe study aims to assess, in an integrated manner, the geotechnical aspects of a gabbroic residual soil located in Northeastern Brazil, focusing on its physical, chemical, hydraulic, and mechanical properties. The research covers the gabbroic body situated in the São João do Sabugi Intrusive Suite, where 20 different points were evaluated, totaling 21 collections with varied characteristics. The study area corresponds to approximately 12.8% of the municipality of Jardim de Angicos, in the state of Rio Grande do Norte. Tests were conducted to determine the physical, chemical, hydraulic, and mechanical properties of the soil. The observed physical characteristics varied widely, making it impossible to establish a generalized pattern for the samples, which ranged from low-cohesion soils to high-plasticity clays. The grain size analysis also suggests potential translocation of clay minerals. Chemical analyses, performed using XRD, XRF, and SEM, indicated the presence of expansive clay minerals, such as montmorillonite, in addition to the formation of chlorite, highlighting an advanced and gradual degree of weathering in the region. Regarding hydraulic properties, the samples exhibited low permeability, on the order of 10⁻⁷ cm/s. In terms of mechanical properties, triaxial compression tests revealed ductile materials, with no characteristic strength peaks and continuous hardening behavior throughout the test. The consolidation test showed expansive characteristics of approximately 3.96%. The gabbroic residual soil in the studied area presents significant variation in its physical and mechanical properties, notably the presence of expansive clay minerals and low permeability. These factors suggest that the use of this soil in geotechnical works must be carefully planned, considering its variability, expansive potential, and ductile behavior. The low permeability also indicates that the soil may be suitable for projects requiring infiltration control, such as earth dams. However, the diversity of observed characteristics reinforces the need for further studies, especially in other areas with gabbroic bodies, to evaluate geotechnical variability in different contexts. This study expands the understanding of gabbroic soils and provides important insights for their use in geotechnical works, contributing to the understanding and planning of applications in conditions similar to those found in Northeastern Brazil.Master Thesis Aplicação de técnicas de geoprocessamento para análise da vulnerabilidade costeira na área entre o Cabo de São Roque e a foz do rio Maxaranguape, no município de Maxaranguape/RN(Universidade Federal do Rio Grande do Norte, 2024-09-30) Macêdo, Emanuella Silva Pereira de; Amaro, Venerando Eustáquio; Scudelari, Ada Cristina; https://orcid.org/0000-0001-7594-1196; http://lattes.cnpq.br/6556306307432176; http://lattes.cnpq.br/4215328958233942; http://lattes.cnpq.br/2740579852284319; Pinheiro, Lívian Rafaely de Santana Gomes; Ingunza, Maria Del Pilar Durante; Souto, Michael Vandesteen SilvaCoastal erosion and flooding are process that directly affect cities near the coastline, causing significant economic, social and environmental damages. Some impacts include land and coastal infrastructure loss, loss of habitats and biodiversity, economic and tourism disruptions, and risks to safety and helth. The study area is located in the coastal zone of Barra de Maxaranguape, on the eastern coast of the state of Rio Grande do Norte (RN), where the city stands out for its economic activities along or near the shoreline, linked to both domestic and international tourism, as well as temporary occupancy by local vacationers. However, due to unplanned growth resulting from permanent and temporary residential occupation and commercial use for tourism over the past three decades, without prior planning or coastal dynamics studies, it is estimated that the situation may worsen over the years. Thus, the main objective of this study is to diagnose the region using geoprocessing tools and numerical modeling of coastal vulnerability under future scenarios to provide a reference for decision-making in mitigation and implementing preventive measures against erosion and flooding damages. The metodology includes the extraction of shoreline data from satellite images (LANDSAT series for multi-decadal and decadal analysis and SENTINEL-2 images for high-resolution analysis), sediment balance analysis using the CASSIE tool, and the application of the Coastal Vulnerability module in InVEST. The results showed that critical areas exhibit high susceptibility to erosion and flooding process, especially in regions with greater human occupation, highlighting the influence of anthropogenic variables on the environment. Simulations indicated that the rise in mean sea level could exacerbate coastal vulnerability, compromising infrastructure and local ecosystems. However, it was noted that there were no significant discrepancies beteween the results from the analyses using LANDSAT and SENTINEL-2 satellite images.Master Thesis Áreas prioritárias à recuperação da bacia hidrográfica do Rio Potengi - RN, Brasil(Universidade Federal do Rio Grande do Norte, 2024-06-26) Sousa, Matheus Natan Ferreira Alves de; Costa, Carlos Wilmer; http://lattes.cnpq.br/6913631503818679; https://orcid.org/0009-0000-6546-3899; http://lattes.cnpq.br/1060335248924504; Attayde, José Luiz de; Rufino, Iana Alexandra Alves; Lollo, José Augusto DiIn order to mitigate the advancement of erosive processes on the Earth's surface, entities responsible for environmental management and oversight have been demanding actions and policies aimed at preserving, maintaining, and restoring environmental quality and integrity. Among these actions are the delineation and Recovery of Degraded Areas (RAD) and the implementation of Payments for Environmental Services (PES). Faced with the challenge of planning territorial actions, multicriteria analysis within a Geographic Information System (GIS) environment has become a crucial decision-making tool, particularly at the watershed scale. Based on attributes of physical, biotic, and anthropic factors, this study determined, through qualitative and quantitative methodologies, the vulnerability to erosion and soil loss in the Potengi River Watershed - Rio Grande do Norte (BHRP-RN). As a result, 9 (nine) critical areas in terms of vulnerability were identified, and 5,111.53 hectares of extensive livestock areas were prioritized for erosion control and the implementation of RDA and PES. Economically, these areas were evaluated based on the net present value of the region's economic activities. Therefore, a minimum value for the economic feasibility of PES programs was established at R$563.32 per hectare per year.