IMPROVEMENT MECHANISM OF SHEAR STRENGTH IN FIBER REINFORCED ASPHALT CONCRETE

Rutting gradually develops and becomes serious on asphalt concrete pavement under repeated high temperature and overload. Fiber-reinforced asphalt concrete (FAC) is able to delay the crack formation and resist the deformation of rutting for asphalt concrete pavement by enhancing its shear strength. Laboratory tests were conducted and obtain the values of the shear strength, rutting depth and dynamic stability of FAC, which provided a reliable database to study the mechanism of the increase of its shear strength. By way of micromechanics, it was found that the bridging function of fiber could consume stress and change stress distribution by anchoring and drawing and lubrication. By means of surface adhesion theory, high surface area of fibers brought high adhesion to asphalt cement, which could improve the road performance of asphalt pavement effectively. The results of this paper show that fatigue life of FAC increases with the addition of fiber, and fibers bring reinforcement effect to asphalt concrete by resisting the emergence and development of permanent deformation.