Laboratory Performance and Field Case Study of Asphalt Mixture with Sasobit Treated Aramid Fiber as Modifier

The use of fiber in asphalt mixtures can improve the mixture’s tensile strength and increase its cracking resistance, but the clumping of fiber in the mixture can weaken the improvement effect. The aim of this research is to assess the properties of Sasobit treated aramid fiber modified asphalt mixture and to validate the field case study. The rutting and stripping resistance of the fiber-modified mixture was identified with the Hamburg wheel tracking device. The low-temperature cracking characteristics of the asphalt mixture were quantified with the disk-shaped compact tension test. Moreover, the dynamic modulus test was adopted to reflect the response of the mixture to different loads and frequencies. The creep slope and stripping slope decreased by 67%, and the number of passes to stripping point and fail point increased by more than 250% after fiber modification. The fracture energy, peak load, and maximum crack mouth opening displacement (CMOD) of the mixture increased more than 10% after fiber modification. The dynamic modulus, rutting parameter, and fatigue parameter of the mixture were improved after fiber modification. The fiber in the mixture improved the stiffness of the mixture at high temperatures. The tensile strength improvement at low temperatures promoted the cracking resistance of the mixture. The cracking number in the fiber modified asphalt pavement was less than that in the control asphalt pavement. Thus, fiber modification could significantly restrict the propagation of cracking in the asphalt mixture. The implementation of fiber in the project can provide experience for future fiber application in asphalt pavement.