https://ri.ufs.br/jspui/handle/riufs/2494 Thu, 01 Oct 2026 20:15:22 GMT 2026-10-01T20:15:22Z http://ri.ufs.br:80/retrieve/5f2efb2a-922b-49ca-9b74-0e4082d721ce/PROEC.jfif https://ri.ufs.br/jspui/handle/riufs/2494 https://ri.ufs.br/jspui/handle/riufs/26189 Título: Efeito da porosidade, da morfologia superficial e do fíler carbonático na carbonatação de compósitos cimentícios reforçados com fibra de celulose Autor(es): Santos, Handellon Kleyton de Jesus Abstract: Since the Industrial Revolution, humanity has intensified greenhouse gas emissions primarily carbon dioxide (CO2) stemming from sources such as the burning of fossil fuels. In the construction industry, cement is the primary source of carbon emissions. During Portland cement manufacturing, specifically the clinkerization stage, a decarbonation process occurs wherein the decomposition of calcium carbonate releases carbon dioxide. Furthermore, the fossil fuels used to heat the kiln also contribute to carbon emissions. Aiming to mitigate the environmental impacts of the construction industry, carbon capture via the carbonation process in cellulose fiber-reinforced cementitious composites (fiber-cement) specifically in board form—emerges as a promising mechanism. Due to their slender profile and large surface area, these boards can serve as carbon reservoirs; additionally, there is no concern regarding steel depassivation, as these boards typically rely on natural or artificial fibers for stabilization. Thus, understanding how to maximize carbon capture in these boards can help the construction sector become more eco-efficient. The general objective of this research is to analyze the kinetics of CO2 uptake in cellulose fiber-reinforced cementitious composites by varying their morphological characteristics and incorporating a carbonate filler (acting as a nucleating agent), while observing the resulting impacts on the composite’s properties and eco-efficiency. To achieve this, cellulose fiber-reinforced cementitious boards were produced and cut into prismatic specimens (16 x 4 x 1.5 cm) representing the following variations: a reference specimen (fiber-free); a porous specimen (fiber-cement with a porous flat surface); a rough specimen (surface with modified geometry); and a specimen incorporating a carbonate filler (with the addition of carbonate filler as a mineral admixture). To evaluate the effects of varying surface morphology and adding carbonate filler, the compositions were subjected to a carbonation process. The specimens were kept at a temperature of approximately 25 °C, 70 % humidity, and a 5 % CO2 concentration; samples were subsequently collected after 0, 1, 3, 7, and 14 days of carbonation. Natural carbonation was also carried out over the same periods to compare the two methods (natural vs. chamber carbonation). Following carbonation, the specimens underwent physical-mechanical testing, as well as assessments of carbonation indicators, eco-efficiency, and carbonation shrinkage. The study concluded that incorporating 6 % cellulose improved carbon capture, a result linked to increased porosity. For samples with modified surface areas, carbon capture results were like those of smooth-surfaced samples; this was attributed to the roughness formation process, which reduced porosity and consequently lowered CO2 absorption, though these samples achieved good eco-efficiency indicators and generally performed better than other samples. Samples with added carbonate filler also demonstrated good carbon capture performance, comparable to that seen with increased porosity. Regarding mechanical properties, adding 6 % cellulose reduced flexural strength by 46.64 % an expected outcome given the higher porosity whereas formulations incorporating carbonate filler or featuring a rough surface yielded values like those of samples with 3 % cellulose. Wed, 26 Aug 2026 00:00:00 GMT https://ri.ufs.br/jspui/handle/riufs/26189 2026-08-26T00:00:00Z https://ri.ufs.br/jspui/handle/riufs/26188 Título: Vigas sanduíche compósitas funcionalmente graduadas reforçadas com fibras, modeladas via função ziguezague modificada com continuidade da tensão de cisalhamento Autor(es): Mota, Thyago Andrade Abstract: Composite sandwich beams have been widely employed in different engineering fields due to their advantageous structural properties, such as high mechanical strength, high stiffness-to weight ratio, and good durability, which favor their widespread application in civil, aeronautical, and aerospace engineering. In this context, composite sandwich beams reinforced with continuous fibers stand out for providing structures with high strength and stiffness. However, these laminates are susceptible to delamination due to the heterogeneity of the material properties across the layers. As an alternative, functionally graded materials have attracted considerable attention because they provide a continuous variation of material properties, thereby reducing interfacial discontinuities. Nevertheless, within laminated structures, the accurate prediction of displacement fields and the proper representation of the variation of transverse shear stresses across the layers remain challenging tasks, even for several higher-order beam theories. Accordingly, this work presents a formulation based on refined zigzag theory, in which a modified zigzag function is proposed to naturally capture the continuity of shear stresses. The proposed model was applied to the analysis of different sandwich beam configurations, including fiber-reinforced laminates, cross-ply laminates, homogeneous sandwich beams, and sandwich beams with functionally graded cores. For fiber reinforced sandwich beams, the influence of the slenderness ratio, stacking sequence, and layer thickness ratio was investigated. For sandwich beams with functionally graded cores, only the mid-span vertical displacement under a concentrated load was evaluated due to the lack of additional reference response fields available in the literature. The formulation was developed separately under the assumptions of plane stress and plane strain within the framework of linear elasticity. Furthermore, the governing equations were derived using Lagrange's Principle and solved through the Ritz method. The results showed good agreement with analytical solutions, experimental results, and reference data available in the literature for different sandwich beam configurations, demonstrating the capability of the proposed formulation to accurately predict displacement and stress fields. Finally, the proposed formulation was shown to accurately reproduce the continuity of transverse shear stresses in both fiber-reinforced and functionally graded sandwich beams, thereby contributing to reducing a gap identified in the literature. Despite the advances achieved, there is still a lack of experimental studies allowing for more comprehensive comparisons. Thu, 13 Aug 2026 00:00:00 GMT https://ri.ufs.br/jspui/handle/riufs/26188 2026-08-13T00:00:00Z https://ri.ufs.br/jspui/handle/riufs/26050 Título: Habitação de interesse social na engenharia civil: análise curricular em instituições federais de ensino em Sergipe Autor(es): Melo, Lúzula dos Reis Abstract: The problem of producing Social Housing (HIS) and access to it by low-income populations has historically been a field of conflicting interests in Brazil. However, it is through the consolidation of public housing policies that the Brazilian government seeks to address sociospatial inequalities by linking housing, infrastructure, and urban integration. Despite legal attempts, such as the enactment of Law No. 11,888/2008, which guarantees free public technical assistance for HIS projects and works, progress in the application of this law has been limited by institutional obstacles, lack of regulation, and a shortage of qualified professionals. These factors have hindered the effective realization of the rights guaranteed by this legislation, contributing to the persistence of a scenario marked by a housing deficit, especially of a qualitative nature, and the continuation of self-construction practices in precarious conditions, with direct impacts on the safety and quality of life of low-income populations. Given this reality, the question arises: how are future Civil Engineering professionals being trained to work with low-income populations, especially in Sergipe? It is assumed that the lack of priority given to the topic of Social Housing in Civil Engineering courses in Sergipe compromises the training of professionals to work critically and attentively with low-income populations. This research aims to analyze the official and interpreted curricula of undergraduate Civil Engineering courses offered by Federal Higher Education Institutions in the state of Sergipe regarding their approach to the topic of Social Housing. The analyses are based on Critical Curriculum Theory, from the perspective of José Gimeno Sacristán, and were carried out in two stages: (i) document analysis of the official and interpreted curricula of the courses offered by the Federal University of Sergipe (UFS) and the Federal Institute of Education, Science and Technology of Sergipe (IFS); (ii) application of a semi-structured questionnaire. The results indicate that the topic of Social Housing and Technical Assistance for Social Housing is addressed indirectly, in a fragmented and poorly systematized way in Civil Engineering training at UFS and IFS. No specific curricular components dedicated to the topic were identified, which highlights a training centered on traditional technical skills. Although professors recognize the social relevance of Social Housing, factors such as curricular and structural limitations hinder the more consistent inclusion of the topic in professional training. Mon, 27 Apr 2026 00:00:00 GMT https://ri.ufs.br/jspui/handle/riufs/26050 2026-04-27T00:00:00Z https://ri.ufs.br/jspui/handle/riufs/25792 Título: Diagnóstico da mobilidade urbana sustentável em capitais regionais: um estudo de caso em Feira de Santana/BA Autor(es): Santos, Eduardo Xavier Abstract: This dissertation is situated within the field of sustainable urban mobility, understood as a planning model that incorporates into urban mobility an agenda guided by measures aimed at promoting quality of life, preserving the environment, and protecting natural resources (Carvalho, 2016). Thus, the objective of this research is to analyze sustainable urban mobility in a Brazilian regional capital, taking the municipality of Feira de Santana (BA) as a case study. According to IBGE (2018), based on the REGIC study, 97 municipalities are classified as regional capitals, characterized as urban centers with a high concentration of management activities and services that exert influence over extensive regional areas. Among these cities, Feira de Santana, Bahia, is selected as the case study because it represents the second largest municipality in the state, with more than 600,000 inhabitants (IBGE, 2022). Furthermore, it constitutes the main economic, commercial, and logistical hub of Bahia’s interior, performing typical functions of a structured regional capital by concentrating demographic and economic flows from its area of influence (Santos et al., 2024). As a methodological instrument, the Sustainable Urban Mobility Index (IMUS), developed by Costa (2008), is adopted, as it is a methodology widely applied in the Brazilian context and has been implemented in six regional capitals over the past five years: João Pessoa (PB), Aracaju (SE), Ribeirão Preto (SP), Passo Fundo (RS), Rio Verde (GO), and Sinop (MT). The IMUS is based on a quantitative and multicriteria approach structured around 87 indicators distributed across nine thematic domains: accessibility; environmental aspects; social aspects; political aspects; transport infrastructure; non-motorized modes; integrated planning; traffic and urban circulation; and urban transport systems. The research draws on data from institutional databases, legislation, urban plans, and field surveys to meet the requirements of the indicators, which are calculated and organized according to a weighting system that allows for the redistribution of values in cases where the application of a given indicator is not feasible. Due to limitations in data availability, 55 indicators were applied in Feira de Santana, corresponding to a completion rate of 63%. Nevertheless, the study remains valid, as indicators were computed across all nine domains, as required by Costa (2008). As a result, Feira de Santana achieved an overall index score of 0.432, highlighting as a strength the presence of regulatory instruments aligned with federal policies. On the other hand, the main weaknesses include the predominance of fragmented actions, low intersectoral coordination, limited intermodality, low quality of urban public transport services, shortcomings in democratic governance, socio-spatial inequalities, and institutional limitations in urban mobility management. These findings indicate a mismatch between the normative framework and the effective implementation of the guidelines established by the National Urban Mobility Policy. A similar pattern is observed among the other regional capitals analyzed, suggesting common characteristics among these municipalities. Based on these findings, five general guidelines are proposed to support future actions and planning initiatives: strengthening the integration between urban planning and mobility; reorienting road space to prioritize sustainable modes; improving and strengthening urban public transport; reinforcing the environmental dimension of urban mobility; and expanding democratic governance and social control mechanisms. Finally, it is concluded that the application of the IMUS proves to be appropriate for diagnosing sustainable urban mobility in Feira de Santana and for guiding improvements in sustainable urban mobility in regional capitals. Thu, 26 Mar 2026 00:00:00 GMT https://ri.ufs.br/jspui/handle/riufs/25792 2026-03-26T00:00:00Z