Fracture Properties of Polypropylene Fiber Reinforced Concrete Containing Fly Ash and Silica Fume

A parametric experimental study has been conducted to investigate the effect of polypropylene fiber on the fracture properties of concrete containing fly ash and silica fume, with five fiber volume fraction (0.04, 0.06, 0.08, 0.1 and 0.12%) used. The results indicate that 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 mid-span 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 with the increase of fiber volume fraction. The variation rules of the fracture parameters indicate that the capability of polypropylene fiber to resist crack propagation of concrete composite containing 15% fly ash and 6% silica fume is becoming stronger and stronger with the increase of fiber volume fraction with the fiber volume fraction not beyond 0.12%.