Effect of polypropylene fiber on fracture properties of cement treated crushed rock

A parametric experimental study has been conducted to investigate the effect of polypropylene fibers on the fracture properties of cement treated crushed rock (CTCR), which is a new pavement composite material. By means of three-point bending method, the fracture toughness, fracture energy, the ultimate deflection in span center, critical crack mouth opening displacement, critical crack tip opening displacement, maximum crack mouth opening displacement and maximum crack tip opening displacement of the specimen of CTCR reinforced with polypropylene fibers were measured respectively. The test results indicate that the addition of polypropylene fibers is helpful to improve the fracture properties of CTCR. Polypropylene fibers have great improvement on the fracture parameters of CTCR. Besides, the fracture parameters increase gradually and the fracture relational curves are becoming plumper and plumper when the fiber volume fraction increases from 0% to 0.1%. Furthermore, the capability of polypropylene fiber to resist crack propagation of CTCR appears to be becoming stronger and stronger with the increase of fiber volume fraction with the fiber volume fraction not beyond 0.1%.