Combined effect of fiber and degree of stabilization on the early age behavior of cement bound granular mixtures

An investigation has been undertaken to study the effect of fiber-reinforcement and different degrees of stabilization on the early age mechanical behavior of cement bound granular mixtures intended to be used as a base layer within pavement structure. Waste plastic fibers (WPF) recycled from soft drink bottles were used at 1% by the mass of aggregate to reinforce cemented mixtures. To stabilize different mixtures, cement content of 3%, 5%, and 7% by the mass of aggregate and by the weight of aggregate and fiber were used for conventional and fiber-reinforced cement bound granular mixture (CCBGM& FRCBGM), respectively. The examined properties include unconfined compressive strength (UCS), indirect tensile strength (ITS), bulk density, and ultrasonic pulse velocity (UPV). The results showed a significant improvement in UCS and ITS as the cement amount increased for both types of mixtures. Incorporating PET fibers at cement content of 5% and 7% resulted in a noticeable improvement of ITS compared to the conventional mixtures while a marginal enhancement in the UCS occurred due to fiber-reinforcement. Both bulk density and UPV were increased as cement content increased, while both were decreased due to the inclusion of waste plastic fibers (WPF). Hence, utilizing waste plastic fiber has a positive and promising effect on the pavement structure from sustainability, integrity, and economic points of view.