Avaliação do comportamento mecânico do concreto reforçado com fibras de poliéster residual

Abstract

The use of residual fibers in the composition of concrete has been the object of several researches that seek to obtain fibers at lower cost, considering materials considered unserviceable and enabling improvements in the physical and mechanical properties of this composite. In this perspective, this research aims to evaluate the effect of incorporating rubberized polyester waste in the mechanical mechanism of concrete. For this purpose, they were analyzed as properties in the fresh and hardened state of conventional concrete reinforced with residual polyester fibers, in two lengths (40mm and 60mm) and in three contents (0%, 0.15% and 0.30% in in relation to the volume of the concrete). In the fresh state, the slump test was performed and for the hardened state, at 28 days, the tests of physical index, axial compression strength, tensile strength by diametrical compression, tensile strength in bending, tensile strength in fracture and tenacity. The results of the treatments increased that the addition of fibers causes a reduction in workability as the addition content and length of the fibers increase. In the hardened state, it was observed that with the addition of fibers there is a tendency to increase the void index and the water absorption content of the concrete. Fiberreinforced concrete with a lower density than fiber-free concrete. The fibers increased the axial compression strength and tensile strength by diametrical compression of all the mixes, with the 40mm fiber reinforced mixes better results. In no flexural tensile test, the mixes reinforced with 60mm residual fibers had the best performance, with the 0.15% reinforcement content changed being the best result. Concretes with fiber fibers tenacity higher than the reference mix. Finally, it was verified that the residual polyester fibers allowed improvements in some mechanical properties of the concrete, increased the deformation capacity and the strength of the cementitious composite.