Testing study on fatigue damage of asphalt mixture with considering the restoration time

Conventional fatigue damage test of asphalt mixture is usually under the condition of. constant stress-mode or strain-mode, the specimen is broken when the cyclic load reaches certain number of times. In fact, vehicles on the road are not continuous, traffic volume is different in different time, there is a time interval between neighbouring vehicles. In this paper, time interval was set between two neighbouring cycles, the effect of recovery way, strain size and temperature on cumulative dissipated energy were analyzed. The results show that: in the early stages, recovery methods have little impact on the cumulative dissipated energy, with the increase of cyclic number, the value of trabecular under unconstrained condition will be greater than that of trabecular under constrained one. The bigger the strain size, the greater the value of cumulative dissipated energy; The lower the temperature, the greater the value of cumulative dissipated energy. Under the conditon of low strain size or high temperature, the value of cumulative dissipated energy decreases linearly. For the high strain or low temperature, there is a sharp decrease between the first cycle and second cycle, and then decreases linely in the later cylcles.