Evaluation of the dynamic modulus and fatigue cracking properties of polyethylene /aramid fiber asphalt mixture based on the S-VECD theory

Fatigue cracking is a primary distress in asphalt pavements, and the fatigue cracking performance can be enhanced through the addition of aramid fiber. In this study, the viscoelasticity of a polyethylene/aramid fiber asphalt mixture (PAAM) was investigated using the simplified viscoelastic continuous damage (S-VECD) theory, and the fatigue damage evolution of PAAM was analyzed. The FlexPAVE™ program was employed to evaluate the fatigue performance of fiber-reinforced asphalt pavement. The results indicated that the increase in air voids led to a decrease in the viscoelasticity and fatigue cracking resistance of PAAM. Compared with other mixing methods, the viscoelasticity and cracking resistance of PAAM with three-layer coarse aggregate dispersion method (TLC) were significantly improved. An increase in fiber content led to a gradual deterioration in fatigue performance of PAAM. In addition, the aging modulus ratio (AMR) increased with increasing temperature, and the impact of aging on the viscoelasticity of PAAM was more significant at high temperature. The results of the FlexPAVE™ program showed that the cracking percentage of fiber-reinforced asphalt pavement with TLC method was reduced by 44% compared with the TRA method. In addition, compared with the non-fiber asphalt pavement, the cracking depth of fiber-reinforced asphalt pavement was reduced by 65%, 81%, 91%, and 76% after aging periods of 1, 2, 4, and 7 days, respectively. This study provides a theoretical basis for improving the application of aramid fibers in asphalt pavement using the S-VECD theory.