Laboratory and Field Toughening Characteristics of Fiber Reinforced Hot-Mix Asphalt Mixtures

This study investigated the enhanced toughening characteristics of plastic fiber-reinforced hot-mix asphalt (HMA) mixtures in laboratory and field tests. The toughening effects of plastic fiber-reinforced HMA mixtures were characterized using direct tensile loading tests. Adding a small quantity of plastic fibers to HMA was found to significantly increase the mixture's fracture energy, which was calculated using the tensile force-displacement curves. The fracture energy model appeared to be governed by the direct tensile toughening of fiber-reinforced HMA's enhanced fiber bridging effects. The field measurement of the fiber reinforced mixture resulted in at least ten times lower tensile strains than those of the plain HMA at the bottom of HMA. This indicates that the fiber reinforced mixture has a superior field performance than the plain HMA does and can extend overall performance life of the mixtures if adding a small amount of fibers such as 0.4% by the mixture's weight within the context of the fiber developed in this study.