Evaluation on the High Temperature Performance of Intermediate and Bottom Layers of Asphalt Pavement in Service

One of the most common forms of distress of asphalt pavements is rutting. The high temperature performance of different asphalt layers in pavement in service is difficult to evaluate. In this paper, based on the example project of G2513 Huai-Xu Expressway, the intermediate and bottom layer of existing pavement was evaluated by means of core analysis, dynamic modulus, dynamic creep, and Hamburg rutting tests. The test results show that the compaction of intermediate course contributes most to rutting followed by bottom and surface course. Dynamic modulus, dynamic creep, and Hamburg rutting tests can be used well for pavement high temperature stability evaluation. And the bottom and intermediate courses is still in good high temperature stability condition. Based on the analysis of dynamic modulus and dynamic creep test results, the mixture at the wheel track zone is in stable development stage, showing better high temperature stability than the shoulder. Combined with the dynamic creep test results, the overall deformation resistance of cored samples from the large rutting section is reduced, which can be estimated due to the decrease of high temperature stability of the surface course. Therefore, special attention should be paid on the surface asphalt layer with large rut depth during the maintenance planning process.