Fatigue Performance Evaluation of Warm-Mixed Rubber Asphalt Mixture for Stress Absorption Layer in Cold Area

Based on the composition design of warm-mixed rubber asphalt mixture and the analysis of the influence of warm mixing on the road performance of warm-mixed rubber asphalt mixture, the fatigue performance of warm-mixed rubber asphalt mixture is studied in this paper. The effects of gradation, asphalt dosage, and strain level on the fatigue life of the mixture are analyzed. Based on a comparative analysis of the fatigue life of warm-mixed and hot-mixed rubber asphalt mixture before aging, it is concluded that the fatigue performance of hot-mixed rubber asphalt mixture is slightly better than that of warm-mixed rubber asphalt mixture. The effect of aging on the fatigue performance of warm-mixed and hot-mixed rubber asphalt mixture is analyzed, and it is concluded that the fatigue durability of aging hot-mixed rubber asphalt mixture decreases much faster than that of warm-mixed rubber asphalt mixture. Based on a comparative analysis of the fatigue performance of three kinds of asphalt mixture used as a stress absorption layer, it is concluded that the fatigue performance of warm-mixed rubber asphalt mixture is basically the same as that of hot-mixed rubber asphalt mixture, but much higher than that of SBS-modified asphalt mixture. A warm-mixed agent can slow down the decreasing rate of fatigue performance of rubber asphalt mixture and improve the aging resistance of rubber asphalt mixture.