The Experimental Rasearch And Microstructure Analysis Of Asphalt Mixture Rut Performance

The layer thickness and gradation, as the most important effect factors to the mechanical properties of Asphalt mixture, have links with the performance and durability of Asphalt mixture, with its widespread application and today’s society traffic demand, the single study on the influence of gradation and layer thickness of a certain type Asphalt mixture on mechanical properties can not meet the requirements of development. Through three common used Asphalt mixture of AC-16、AC-13、AC-20, the best gradation is determined in this article, which gets the high temperature dynamic stability and deformation through the rutting test under 60℃ environment, the data analysis showed that the high temperature stability of AC-16、AC-13 and AC-20 Asphalt mixture decreases. The random aggregate model indicates that there are same gradation in both simulation and tests, which analyzed that the plastic deformation of Asphalt mortar under moving load is the main reason for permanent deformation, considering the increase of specimen load times will increase the plastic deformation of Asphalt mixture, which provides the reference for the gradation design and the thickness choose of Asphaltgradation, finally guiding the theory research and practical work.(1)Determining the design graduation of AC-16、AC-13、AC-20 through mix design. Based on the best data of the MAO volume density、Marshall、Immersion Marshall、Maximum theoretical density method(vacuum) etc, the best Asphalt content about the Asphalt mixture above under three different ratio are respective 5.17%、5.38% and 4.8%.(2)The AC-13 Asphalt mixture specimen with the thickness of4cm、5cm、6cm and the AC-16、AC-20 Asphalt mixture specimen with the thickness of 5cm、6cm、7cm are made in indoor laboratory by using wheel grinding method. According to the test specification, the rutting test of samples with different height and gradation are carried out under the same condition by rut meter, which observed the deformation of the specimen, collected the time histories of deformation and got the result of high stability tests. According to the test results, the influence of specimen thickness and Asphalt mixture gradation on the Asphalt mixture dynamic stability at high temperature are compared, which analyzed the mechanism of action and put forward the improvement opinions.(3)The actual size of aggregate are calculated and generated by the experiment proportion of AC-16、AC-13、AC-20 Asphalt mixture, and the actual aggregate gradation is generated in the random aggregate model. The concrete damage constitutive is established respectively referred to Asphalt mortar stress-strain relationship, and the mechanicalrespond of aggregate in meso scale model is analyzed after inputting the moving load.