PPGECAM https://repositorio.ufpb.br/jspui/handle/tede/5433 2026-11-12T02:02:02Z 2026-11-12T02:02:02Z Rocha, Fabíola Luana Maia https://repositorio.ufpb.br/jspui/handle/123456789/39710 2026-11-11T10:08:07Z 2026-02-05T00:00:00Z

Título: Argamassa autonivelante com incorporação de resíduos como agregado leve: otimização de dosagem da matriz cimentícia e avaliação das propriedades nos estados fresco e endurecido Autor(es): Rocha, Fabíola Luana Maia Orientador: Nóbrega, Aline Figueiredo da Abstract: The construction industry has increasingly sought materials that combine efficiency, sustainability, and enhanced productivity. In this context, self-leveling mortar (SLM) has gained prominence due to its high flowability and workability. However, its mix design still lacks consolidated standard specifications, and its formulation generally requires a high content of fines, particularly Portland cement (PC), as well as significant variability in admixture dosage. At the same time, the use of lightweight screeds has emerged as an important strategy for reducing the self-weight of buildings while improving acoustic insulation, thereby highlighting the potential of incorporating lightweight aggregates into SLM. In this context, the present study aimed to optimize the mix design of SLM using the Taguchi method and to assess the feasibility of incorporating Expanded Polystyrene (EPS) and Ethylene-Vinyl Acetate (EVA) waste as lightweight aggregates. For this purpose, the materials were characterized in terms of their physical, chemical, mineralogical, and thermal properties. During the mix design stage, five independent variables were investigated, namely cement, limestone filler, sand, water, and superplasticizer admixture, with spread flow adopted as the response variable. This approach enabled the development of a predictive equation and the definition of a reference mixture. The model showed good agreement between predicted and experimental results, with the reference mixture presenting a predicted spread flow of 25.81 cm and an experimental value of 25.20 cm. Based on this reference composition, sand was partially replaced by EVA or EPS, separately and by volume, at replacement levels ranging from 30% to 80%. In the fresh state, all mortars were evaluated in terms of spread flow, V-funnel flow time, fresh bulk density, flow retention, and regeneration time. In the hardened state, compressive strength, flexural tensile strength, density, substrate bond strength, and microstructure were assessed. The results showed that flowability was mainly influenced by the superplasticizer admixture, followed by water and limestone filler. In the fresh state, all SLM mixtures containing EVA and EPS exhibited spread flow values between 25.0 cm and 25.6 cm and V-funnel times between 7.0 s and 8.1 s, confirming behavior compatible with SLM applications and meeting the criteria established by the European Federation for Specialist Construction Chemicals and Concrete Systems, EFNARC (2002). Mixtures containing EPS achieved this spread flow range with lower superplasticizer contents, from 0.84% to 0.86%, whereas mixtures containing EVA required higher dosages, ranging from 1.03% to 1.12%. In the hardened state, density decreased as the EVA and EPS contents increased. Compared with the reference mixture, which exhibited a density of 2.16 g/cm³, the 80EVA and 80EPS mixtures reached 1.74 g/cm³ and 1.71 g/cm³, respectively, corresponding to reductions of approximately 19.6% and 20.6% in apparent density. Regarding compressive strength at 28 days, the reference mixture reached 27.58 MPa, whereas the 30EVA, 40EVA, and 30EPS mixtures achieved 20.18 MPa, 19.83 MPa, and 24.28 MPa, respectively. Even at the highest replacement levels, the results remained compatible with flooring applications, with compressive strengths ranging from 12.68 MPa to 12.92 MPa for the mixtures with the highest EVA contents and 16.6 MPa for the 80EPS mixture, all of which exceeded the 5 MPa typically required for screed mortars. In the substrate bond strength test, the 80EVA and 80EPS mixtures achieved values of 0.95 MPa and 0.66 MPa, respectively, both higher than that of the reference mixture, which reached 0.37 MPa. Overall, the SLM mixtures investigated in this study exhibited characteristics and performance that demonstrate the technical feasibility of their application in screeds incorporating lightweight waste-derived aggregates, while also aligning with Sustainable Development Goals (SDGs) 9, 12, and 13. Editor: Universidade Federal da Paraíba Tipo: Tese

2026-02-05T00:00:00Z Silva, Yves de Sousa https://repositorio.ufpb.br/jspui/handle/123456789/39552 2026-10-09T06:11:56Z 2007-03-30T00:00:00Z

Título: Gestão ambiental integrada de bacias hidrográficas : um diagnóstico multicriterial do alto curso da bacia urbana do Rio Jaguaribe Autor(es): Silva, Yves de Sousa Orientador: Lima, Eduardo Rodrigues Viana de Abstract: Currently, urban planning and management are characterized as complex governance practices, with particular emphasis on mitigating environmental degradation and addressing the socioeconomic deficiencies affecting segments of the population. In this context, the search for supportive management methodologies that encompass the multifaceted challenges of urban environmental dynamics becomes essential to optimize actions that promote socioeconomic and environmental balance, dimensions traditionally regarded as difficult to integrate. Urban watersheds are now considered particularly suitable units for conducting multicriteria diagnoses, as they allow the consideration of multiple factors and provide an ideal spatial framework for understanding local realities. Accordingly, this study conducts an integrated analysis aimed at producing a multicriteria diagnosis of the urban environment under investigation, using as a case study the upper course of the Jaguaribe River Watershed, which encompasses parts of ten neighborhoods in João Pessoa, Paraíba, Brazil. To this end, consolidated methodologies were adapted, incorporating a structure of indicators addressing both environmental and socioeconomic dimensions. The selected environmental variables were the Soil Protection Factor and the General Water Quality of the watershed. For the socioeconomic dimension, available data from the Human Development Index (HDI) and the Environmental Salubrity Indicator (ISA) were used. After weighing the results and establishing a classification structure for valuing the selected indicators, it was found that, due to current land use, the watershed is classified as poorly protected. Regarding the general water quality of the Jaguaribe River, the analysis concluded that, on average, water quality deteriorates by approximately 57% from the source to downstream. The watershed also showed medium human development and low environmental salubrity. Ultimately, the multicriteria diagnosis of these variables revealed that the study area is significantly compromised and currently in a state of imbalance. Editor: Universidade Federal da Paraíba Tipo: Dissertação

2007-03-30T00:00:00Z Cordeiro, Alvan Antas https://repositorio.ufpb.br/jspui/handle/123456789/39549 2026-10-09T06:11:58Z 2025-12-09T00:00:00Z

Título: Ferramenta para dimensionamento de reservatório para aproveitamento de água de chuva no Semiárido brasileiro por meio do coeficiente de transbordamento volumétrico Autor(es): Cordeiro, Alvan Antas Orientador: Athayde Júnior, Gilson Barbosa Abstract: Water scarcity in the Brazilian Semi-Arid Region is a historical and structural challenge, exacerbated by climate change and the irregular distribution of rainfall. In this context, Rainwater Harvesting Systems (RHS) emerge as a vital solution for water supply, especially in rural communities. The efficiency of these systems is directly linked to the correct sizing of the reservoir, which is their most costly component. This study proposes the development and application of a tool for sizing rainwater reservoirs in the Brazilian Semi-Arid Region, using the Volumetric Overflow Coefficient (VOC), defined as the ratio between the annual spilled volume and the reservoir capacity. The objective was to create a method that, by minimizing the VOC, would indicate the "optimal" reservoir volume while minimizing losses. The methodology was based on the simulation of the daily water balance for a 30-year historical series (1993-2022), covering the entire semi-arid region. Maps of VOC values generated from 40 scenarios were analyzed, which combined different catchment areas (50 to 200 m²), water demands (domestic and irrigation), and reservoir volumes (2 to 50 m³). The results demonstrated that the catchment area is the predominant factor for system efficiency, with larger areas resulting in higher VOC for the same reservoir volume. It was found that increasing the reservoir capacity beyond 20 m³ generally does not substantially reduce spillage losses. Based on these analyses, a Python algorithm with a graphical interface was developed, allowing the user to input their location, catchment area, and demand to obtain the optimal reservoir volume and the system's reliability. The tool eliminates offers a solid technical basis for planning efficient, sustainable RHS adapted to real local needs. Editor: Universidade Federal da Paraíba Tipo: Dissertação

2025-12-09T00:00:00Z Araújo, Mikael Bernardo Vasconcelos de https://repositorio.ufpb.br/jspui/handle/123456789/39493 2026-10-08T06:11:03Z 2024-09-03T00:00:00Z

Título: Estimativa do potencial de geração de biogás proveniente das atividades econômicas grandes geradoras de resíduos orgânicos da cidade de João Pessoa (PB) Autor(es): Araújo, Mikael Bernardo Vasconcelos de Orientador: Morais Júnior, Joácio de Araújo Abstract: Climate change is a consequence of anthropic exploration through the unsustainable use of natural resources and inadequate disposal of solid waste. Law No. 12,305, of August 2, 2010, which established the National Solid Waste Policy (PNRS), provides that some economic activities, and large generators, draw up their plans for waste management. In Brazil, the definition of large generators is not standardized, and the lack of criteria and elements subject to inspections makes inspections difficult. In João Pessoa, Decree No. 8,886, of December 23, 2016, qualifies establishments that produce more than 200 liters per day as large generators. This study aimed to investigate the potential for biogas production from organic waste from large generating activities in the city of João Pessoa. Due to the difficulty of obtaining data from public bodies, previously researched sectors were mapped, including hotels, bars and restaurants, farmer markets, supermarkets and Empresa Paraibana de Abastecimento e Serviços Agrícolas (EMPASA). Quantification of waste was carried out using a specific method for each type of large food waste generator. The estimate of biogas generation potential was based on the Scholl Canyon mathematical model. It is possible to highlight that the research has an innovative character, as no research was found in the bibliometric review carried out in the Scopus and Web of Science databases, which covers all large generators of organic waste, especially in João Pessoa. The study revealed a total organic waste mass estimated at 27,544 ton.year-1, with a potential for methane generation between 50,183 and 66,911 m³.year-1, which indicates a capacity for generating electrical energy of 2,035,407 kWh.year-1, which ratifies the feasibility of using this waste through more technological and sustainable disposal methods, such as the implementation of a biomethanation plant in the city of João Pessoa. Editor: Universidade Federal da Paraíba Tipo: Dissertação

2024-09-03T00:00:00Z