Rutting test improving methods of asphalt mixture

The difference between laboratory rutting test conditions and actual pavements was analyzed.Rutting test improving methods were proposed,which included reducing loading speed under heavy loading condition,developing full-thickness rutting tests as conventional rutting tests' complement,forming thermal gradient in full-thickness rutting samples.Rutting tester was improved,and the testing duration times at different loading speeds and the dynamic stability calculating methods were confirmed.Rutting tests were carried out by using improving rutting tester under different conditions.These tests included asphalt mixture's rutting tests under heavy loading and low speed,full-thickness rutting tests under uniform temperature field and under thermal gradient.The anti-rutting performance evaluation method of asphalt mixture was proposed based on the improving methods.Test result shows that dynamic stability of asphalt mixture reduces by 50%-70% when loading speed decreases by 2/3,and the dynamic stability of full-thickness sample is 20%-50% lower than that of surface course asphalt mixture.These can fully explain the rutting disease of asphalt pavement at upgrade section,and the improving methods are feasible.1 tab,3 figs,14 refs.