Study On The Rutting Resistance Of Double-Layer Asphalt Surface Course

Rutting is one of the common distresses in the asphalt pavement and the issue of rutting has been the research focus for the road researchers.The anti-rutting performance of bituminous mixtures can’t directly reflect that of the surface course of the asphalt pavement.Therefore,it is very important to study the anti-rutting performance of the surface course of the asphalt pavement.At present,the relative research is mostly on the three-layer or more layers of the newly built high-grade road.Otherwise,studies for the double-layer is fewer and there has never been wheel-tacking test based on the actual structure of the asphalt surface course.Thus,it is of great significance to conduct research on the anti-rutting performance of double-layer asphalt surface course for the actual pavement structure such as the newly-built double-layer asphalt pavement and the asphalt overlayer,which can provide guidance for the anti-rutting design of the double-layer asphalt pavement.Firstly,Rutting test plan was drawn out,the raw materials of the bituminous mixtures were tested and the mix design of the asphalt mixture was employed.Then,domestic wheel tracking tests with different loading speed are carried out and the fluctuations of the dynamic stability of asphalt mixture with different thickness were compared.The relationship of the dynamic stability between two-layer asphalt surface structure and horizon asphalt mixture is established with the application of the multiple regression analysis method and the horizon decomposition equation method.Then,the method of the horizon decomposition equation is recommended to establish the relationship after comparison.Secondly,the Hamburg rutting test was carried out and the change of the rutting depth with thickness of different asphalt mixture was compared.The result shows that the rutting depth of asphalt mixture increases in different levels with the increase of the thickness of asphalt mixture,.The rutting depth of double-layer asphalt surface course was analyzed by variance analysis,which shows that the upper and lower layer materials both have significant effects on the rutting depth of the double-layer asphalt surface structure.Considering the layer location and the layer thickness of the asphalt mixture,the function of rutting depth between the double-layer asphalt surface structure and the horizon asphalt mixture is established.Finally,the domestic wheel tracking tests and the hamburger rutting test were compared and analyzed from the aspect of test method,the evaluation method and the test result.The correlation of the evaluation of the anti-rutting performance between the above tests with different loading speed is good.The domestic wheel tracking test is finally recommended to establish the dynamic stability relationship between the double-layer asphalt surface structure and the horizon asphalt mixture after comprehensive consideration of the price,the popularity the engineering practicality and so on.