Dynamic and Static Characterization of Polypropylene Fiber-Reinforced Dune Sand

Abstract

Dune sands characterized by a susceptibility to large deformations can be a useful pavement construction material if reinforced or treated with cement. Sand can be easily reinforced with synthetic fibers to increase its stiffness and load-carrying capacity. This study was undertaken to investigate the resilient behavior of polypropylene fiber-reinforced sand. Triaxial, California bearing ratio (CBR), and resilient modulus tests were conducted on fiber-reinforced sand as well as unreinforced sand, and the results compared. The optimum fiber content was found to be 0.4% by weight. The triaxial shear strength of the fiber-reinforced sand specimens revealed that there were two modes of failure, fiber-sand bond failure and fiber failure, and the internal friction angle depended on the mode of failure. Synthetic fiber-reinforced sand has greater CBR values than those of unreinforced sand. The effect of fiber reinforcement on the resilient modulus, MR, values was investigated in terms of resilient modulus model parameters. In general, the model parameters revealed a decreasing effect of both the deviator and confining stresses on the MR values up to 0.2 to 0.4% fiber content. The permanent deformation of sand specimens was reduced by the addition of fibers, and the permanent deformation decreased as fiber content increased.