FRCU - GIMCE: Grupo de Investigación de Mecánica Computacional y de Estructuras

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Subject: search.filters.subject.Shear strength

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    Vigas de gran altura de hormigón reforzado con fibras. Evaluación de la resistencia al corte
    (2021-06-05) Rougier, Viviana Carolina; Denardi, Miqueas Ceferino; Vercesi, Darío Orestes
    Concrete is very strong in compression, but it has a very low tensile strength. To improve its tensile strength, reinforcing steel is often used in the concrete. However, the reinforcement of the cementitious matrix with discrete fibers has gained increasing recognition. The addition of fibers randomly distributed as reinforcement of cement-based matrices can produce a material with improved tensile strength and deformational characteristics. Different types of fibers can be employed to reinforce concrete. Nevertheless, the use of steel fibers is particularly attractive in concrete members with high reinforcement congestion, like deep beams, when conventional stirrups can be eliminated or reduced. So, the effects of steel fibers on the shear strength of reinforced concrete deep beams were evaluated by different ways: experimental, theoretical, and numerical. A total of six beams were subjected to a concentrated load P at their center and two steel fiber volume fractions were used. Two specimens were elaborated with plain concrete and longitudinal steel reinforcement. Web reinforcement was used in one of those beams and the other was made without stirrups. The others four specimens were built with steel fibers reinforced concrete (SFRC), longitudinal steel reinforcement and without stirrups. The test results indicated that the fibers influenced the shear strength of reinforced concrete deep beams. Shear strength increased with increasing fiber volume fraction, but steel fibers could not totally replace the conventional steel stirrups. Comparisons between experimental shear strength values and predictions, using empirical models developed by different authors, showed satisfactory results. In addition, the comparison between numerical and experimental values indicated that finite element analysis (FEA) was a reliable tool to simulate nonlinear behavior of SFRC deep beams.
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    Shear behaviour of FRP retrofitted masonry with uncertainties in the material properties: parametric study
    (2015-11-22) Escalante, Mario Raúl; Rougier, Viviana Carolina
    Masonry structures shear failure is generally preceded by a massive cracking development in the mortar joints. For this reason, the mortar joints limit the final strength. Mechanical properties degradation and structural safety loss make the rehabilitation or reinforcement necessary. The reinforcement technique with fiber reinforcement polymers has experimentally proved to be very effective. However, in the present, analytical and numerical capacity to quantify this retrofitting system efficiency is still subject of research. In order to improve these intervention techniques it is necessary to have more experimental data and a numerical tool to simulate their behavior. Although the in-plane mechanical behaviour of unreinforced masonry and masonry retrofitted with fiber reinforced polymer (FRP) laminates has been studied by several authors, the analytical modelling of mechanical behaviour of masonry remains an open problem, due to its natural variability and inhomogeneity. A coupled damaged-plasticity model in which bricks and mortar are separately modelled (micro approach) is considered to carried out a parametric study of in plane shear behavior of unreinforced and FRP retrofitted scaled masonry walls. Composite materials are simulated as an elastic orthotropic material. Parametric study results are compared with experimental data obtained from unreinforced and FRP reinforced panels subjected to shear loads.