Effect of different fibers on the performance of concrete structures

Abstract

Integration of fibers in concrete marked an outstanding milestone in the development of construction materials due to the enhancement in concrete performance such as ductility and tensile strain capacity. Since its invention, several studies aimed at exploring different types of fibers in an attempt to increase the toughness of concrete, bridge over cracks and restrain them from widening thus improving concrete durability and structural integrity. Consequently, extensive research investigated the effects of steel fibers on concrete structures which in turn resulted in a substantial development of UHPC, however, limited studies discussed the incorporation of synthetic fibers in concrete containing coarse aggregates, and PVA fibers in particular that are showing promising results in terms of concrete performance. The aim of this research is to study the effect of PVA fibers incorporation compared with PP and steel fibers, on the mechanical properties of concrete, its impact on beams with or without either longitudinal or transversal reinforcement and its resistance to pull-out of rebar. Therefore, six different mixtures were prepared, which consist of a control mixture, two mixture containing PVA fibers at 0.5% and 1% fiber volume, similarly, two mixtures containing PP fibers at 0.5% and 0.85% fiber volume and lastly a mixture containing 0.5% steel fibers. For each mix, five cylinders, two rectangular prisms, two beams and a cubic mold were casted. The overall results showed a preference for mixtures containing PVA fibers in terms of concrete performance such as compressive strength, splitting tensile strength, modulus of rupture, bond strength, flexural strength, and shear strength, showcasing the importance of PVA fibers usage in future applications.