Research On Rut-Resistance Of Asphalt Mixture

Asphalt concrete pavement was used widely in our country because of its excellent performance. More than 95per of the express way used the asphalt concrete pavement. Under the influence of increasing traffic volume and axial load, overloading, tube running and the continuous high temperature, rut on the asphalt pavement had become the most serious factor that reducing the running quality of the pavement. In order to prolong the pavement life, researching on the mechanism and the factor producing rut, and then taking some action to prevent or reduce rut had become a attractive problem.First, investigated the rut on the express way, learnt the relations between the time and the rut depth, analyzed the cause producing rut, measured the thickness, the bulk density and the maximum theoretical density of the sample, made the asphalt extraction test, the aggregate classing test, and then compared the test results of the samples taken from the rut, the swell and the stop way, summarized the mechanism that generated the rut basing on the changing discipline of the asphalt mix volume.Second, analyzed the advantage and disadvantage of the using rut evaluating index, evaluated the veracity of dynamic stable degree and relative distortion ratio. The conclusion was that for evaluating the high temperature stability of asphalt mix the dynamic stable degree was better than the relative distortion ratio index. For overcoming the shortcoming of dynamic stable degree index, the paper imported a second index-intercept b₀ working together with the old one,and then analyzed the influence of the asphalt dosage to the b₀ ,compared the relation between the b₀ and the compact distortion, at last discussed the possibility calculating the dynamic stable degree with the distortion in time of 30min and 60min.Third, researched the influence of the soft point of the bitumen,environment temperature, compacting degree, pressure and the thickness of the asphalt layer to the high temperature rut-resistance of the asphalt mix with the results of rut test.Finally, using the APBI program calculating the stress distributing on the real pavement structure and the rut test sample analyzed the areas that might generate rut. Change the test condition of rut test, found the primary factor that affect the test result, put forward the supplement provision of the complex board rut test. With ten kinds of complex board structures the paper analyzed the transforming discipline of the complex board.