Análisis del comportamiento a flexión de vigas de hormigón reforzado con fibras de polipropileno / polietileno”

Abstract

The addition of fibers in concrete represents a new technique aimed at improving the tensile behavior developed by simple concrete, although its use is relatively new, more and more research seeks to characterize how fibers influence the concrete properties. The present degree work studied the influence of polypropylene/polyethylene fibers (Tuf Strand SF) in concrete. The characterization of the properties of the aggregates are necessary to get the dosage of the concrete, using a resistance of 240 kg/cm2 to compression. Dosages of 3 and 6 kg/m3 of fiber and simple concrete were used to get a comparative analysis, making a total of 27 50x15x15cm beams according to the recommendations of ASTM 1609 standard. Once the results were obtained, the Load vs. Deflection graphs were prepared to compare deflections, residual strengths and fracture energy between the different volumetric fractions. The study of fiber distribution was carried out by counting fibers, in specified areas, of the semi-sections of the specimens, obtaining the orientation coefficient by areas and total. The comparison of the performance of simple and fiber-reinforced concrete allowed us to verify that the addition of fibers in the concrete improves its ductility and the fiber count corroborated the influence of the "Wall Effect" on the distribution of fibers in the concrete matrix.