Effect of polypropylene fiber on fracture properties of high-performance concrete composites

Abstract

AbstractA parametric experimental study has been conducted to investigate the effect of polypropylene fiber on the workability and fracture properties of high-performance concrete (HPC) composites containing fly ash and silica fume, with the five fiber volume fractions (0.04%, 0.06%, 0.08%, 0.1%, and 0.12%) used. The results indicate that the addition of polypropylene fiber decreases the workability of the HPC composites containing fly ash and silica fume. With the increase in the fiber volume fraction, both of the slump and the slump flow decrease gradually. Furthermore, the addition of polypropylene fiber has greatly improved the fracture parameters of concrete composite containing 15% fly ash and 6% silica fume, such as fracture toughness, fracture energy, effective crack length, maximum midspan deflection, the critical crack opening displacement, and the maximum crack opening displacement of the three-point bending beam specimens. When the fiber volume fraction increases from 0% to 0.12%, the fracture parameters increase gradually. The variation rules of the fracture parameters indicate that the capability of the polypropylene fiber to resist the crack propagation of the concrete composite containing 15% fly ash and 6% silica fume is becoming stronger and stronger with the increase in fiber volume fraction with the fiber volume fraction not above 0.12%.