Análise do comportamento de vigas de concreto reforçado com fibras de polipropileno

Abstract

This research aims to analyze the behavior of concrete beams reinforced with polypropylene fibres. This type of reinforcement has been increasingly used in construction, with the aim of improving the traction properties of concrete, combating the spread of microcracks by retraction, improve the impact capacity and durability of the concrete structures. For this purpose, an experimental study was carried out on twelve concrete beams of dimensions (150x150x600mm) reinforced with polypropylene fibres ranging in four groups at 0.35%, 0.45% and 0.55% fibres per m3 of concrete and reference without fibres. For analysis, mechanical tests were carried out in four points following the recommendations of NBR 12142 (ABNT, 2010), the influence of fibres on the contribution of traction resistance in flexion was assessed. The results obtained showed that the beams reinforced with polypropylene fibres at 0.35% fibres/m3 showed a significant increase in their strength compared to the other groups with and without fiber reinforcement. All fibrous groups showed a change from fragile to ductile behavior. In addition, the beams with 0.55% fibres showed greater ductility, but less contribution in traction resistance. Based on the results, it concludes that the use of polypropylene fibres as reinforcement in concrete beams is efficient. However, it is important to stress that additional studies are needed to deepen knowledge about the performance of these materials in different situations