https://repositorio.ufu.br/handle/123456789/5144 Wed, 15 Jul 2026 16:44:40 GMT 2026-07-15T16:44:40Z https://repositorio.ufu.br:443/retrieve/811ec787-c69a-4074-aac4-e3ba9f437cac/FACIV.jpg https://repositorio.ufu.br/handle/123456789/5144 https://repositorio.ufu.br/handle/123456789/48855 Title: Uso combinado de fibras de PVA e PP em matriz com fíler calcário e metacaulim: efeito nas propriedades de compósitos cimentícios engenheirados Abstract: Engineered Cementitious Composites (ECC) are fiber-reinforced materials characterized by high ductility and strain-hardening behavior. The typical formulation of these composites employs fly ash as a partial cement replacement and 2% polyvinyl alcohol (PVA) fibers. However, the irregular availability of fly ash in some regions, combined with the high cost of PVA fibers, has driven the search for more viable and sustainable alternatives. In this context, this work aimed to investigate the impact of fully replacing fly ash with a combination of metakaolin and limestone filler in the ECC matrix, as well as to evaluate the effect of hybridizing PVA and polypropylene (PP) fibers on the composite's properties. The experimental program was developed in two stages: (1) formulation of matrices with full replacement of fly ash by metakaolin and limestone filler in proportions (1M1C and 1M2C), determining the superplasticizer content by mini-slump test; and (2) study of the hybridization of PVA and PP fibers at volumetric substitution levels of 0%, 25%, 50%, 75%, and 100% in two distinct matrices. The results showed that the matrix containing metakaolin and limestone filler (1M2C) exhibited workability and mechanical strength similar to the reference matrix (M45), making it a viable alternative. Fiber hybridization significantly affected the composite's behavior. The mixture with 1.5% PVA and 0.5% PP (1.5A_0.5P) offered the best balance between strength and ductility. Increasing the PP content reduced workability and flexural strength but increased deformation capacity. Microstructural analysis confirmed distinct failure mechanisms: rupture of PVA fibers and pull-out of PP fibers. The combined use of metakaolin and limestone filler proved viable for replacing fly ash in ECC production. Fiber hybridization allows the adjustment of ECC properties to meet specific application requirements. Thu, 05 Feb 2026 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/48855 2026-02-05T00:00:00Z https://repositorio.ufu.br/handle/123456789/48577 Title: Fluxo auxiliar para tomada de decisão em projetos de fundações em solos colapsíveis Mon, 23 Feb 2026 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/48577 2026-02-23T00:00:00Z https://repositorio.ufu.br/handle/123456789/48564 Title: Memorial descritivo Tue, 17 Mar 2026 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/48564 2026-03-17T00:00:00Z https://repositorio.ufu.br/handle/123456789/48449 Title: Análise experimental de blocos sobre duas estacas metálicas com armadura metálica e não-metálica de barras de polímeros reforçada com fibra de vidro (GFRP) Abstract: Pile caps are fundamental structural elements in deep foundation systems, responsible for transferring loads from the superstructure to the piles. Due to their typical exposure to aggressive environments, such as high moisture conditions, these elements are prone to deterioration associated with steel reinforcement corrosion, which motivates the investigation of more durable reinforcement alternatives. In this context, this study experimentally evaluated the structural behavior of rigid pile caps supported by two steel piles, designed according to the strut-and-tie method, comparing models reinforced with CA-50 steel bars and glass fiber-reinforced polymer (GFRP) bars. All models were designed with identical geometry, loading conditions, and concrete strength, varying only the type and distribution of the main tensile reinforcement. The experimental program included material characterization tests, load tests up to failure, and detailed instrumentation to monitor strains, displacements, crack development, and load distribution at the supports. The results showed that steel-reinforced pile caps exhibited behavior consistent with rigid block assumptions, presenting lower deformations and better crack control. Conversely, GFRP-reinforced pile caps showed larger deformations and crack widths, indicating a more flexible structural response, even when designed using the same criteria. It was also observed that distributing the GFRP reinforcement along the entire length of the tie resulted in improved structural performance compared to concentrating the reinforcement only in the anchorage region. The study concludes that the use of GFRP bars in pile caps is structurally feasible in terms of ultimate strength; however, additional design criteria related to deformation and crack control are required. Fri, 06 Feb 2026 00:00:00 GMT https://repositorio.ufu.br/handle/123456789/48449 2026-02-06T00:00:00Z