Mechanism Analysis On Rutting In Asphalt Pavement And Study On Rutting Test

With the formation of the national expressway network, premature damage of asphalt pavement is increasingly serious. Particularly, with the aggravation of axis and canalization of traffic, rutting has become the first one of the premature damage phenomenon. Rutting can be seen everywhere in our country, it seriously affects service performance of asphalt pavement. So, we must take the rutting as the most exigent problem to solve. This paper discusses the mechanism of rutting in asphalt pavement and the application of Hamburg Wheel-tracking Device(HWTD) test to evaluate the high temperature performance of asphalt pavement.The overall investigation of rutting in asphalt pavement of Xihu Expressway have been completed, the results show that the depth of middle course is maximum. Through further study on the core samples of different sections show that asphalt content, gradation and volume of air voids are important for rutting. The improper gradation of aggregate and asphalt content for surface cause the serious damage of rutting. The HWTD test results show that middle course is the worst for high temperature performance in the asphalt pavement. At the same time, the results show that poor quality of material and construction cause damage of rutting. Grey correlation analysis indicates that rate of rutting is the most important factor for rutting. So, HWTD test is the best way to evaluate high temperature performance of asphalt pavement. And it could avoid making mistake for analysising mechanism of rutting because other indexes show obvious vaiation.HWTD test under different test condition are reaearched. Results show that temperature, water, specimen specification, molding way, time and anti-rutting additive affect results of test. Analysis indicate that the test conditions which the temperature is 50℃and the specimen is in the water could distinguish high temperature performance of asphalt mixtures. The rate of rutting is better to evaluate the results of HWTD test than the depth of rutting. At the same time, the results of cylindrical specimen well related with the results of plain specimen. It indicate that the rutting test of asphalt pavement core could evaluate high temperature of asphalt pavement.Poor quality of construction cause poor high temperature performance of asphalt pavement. Based on the analysis of the results of actual pavement and laboratory rutting test, this paper puts forward HWTD test as a method for evaluating high temperature performance of asphalt pavemet. And it could provide a basis for quality control of pavement construction.