Experimental analysis of influence factors on high temperature stability of asphalt mixture

Different types of asphalt mixture with different gradation are designed.The effects of load,temperature,material type and water intrusion(hot water immersion and freeze-thaw cycle) on high temperature stability of asphalt mixture are studied by rutting test and static creep test under single axle compressing.Test results show that load and temperature influence high temperature stability of asphalt mixture seriously.Due to the viscosity of asphalt mixture,with the increase in load and temperature,the dynamic stability of asphalt mixture is reduced with exponential relationship.The asphalt mixtures with middle gradation(Basalt AC13-2,Limestone AC20-5) has better high temperature stability,but the fine graded asphalt mixtures is the worst;accordingly asphalt mixtures with large size aggregate is better than those with small size aggregate.The effect of water seriously weakens the high temperature stability of asphalt mixture,and the impact of the freeze-thaw cycle is much stronger than the hot water immersion.Besides,Burgers model can be used to characterize the creep performance of the asphalt mixture before and after water damage,and the viscoelastic parameters are influenced by water intrusion.The water intrusion is extremely unfavorable to anti-high-temperature deformation capacity of asphalt mixture.