Partial hourly pavement temperature variation measured in Shanghai was analyzed. Cumulative frequency of high temperature (above 50 °C defined in this paper) was more than 90%. However, cumulative frequency of moderate temperature (20 °C to 50 °C defined in this paper) was less than 10%. Then permanent deformation (PD) of two asphalt mixtures at the temperatures ranging from 20°C to 60°C was measured using the APA (asphalt pavement analyzer). The results show that PD at 40°C can be as high as 50% of that at 60 °C. Therefore, the PD property should be researched systemically. Firstly, the cumulative PD curve of a typical asphalt mixture was measured and defined by two zones. In the primary zone, the PD accumulates rapidly. The incremental PD tends to decrease, reaching a constant value in the secondary zone. Then, the PD property of asphalt mixture under varying temperatures was researched in laboratory. The result shows that the trend of the PD curves at the second stage was the same as but less than that at the first stage. Based on this study, it was concluded that temperature, number of load cycles, stress history, and intermission time are some of the major influencing factors on the PD of asphalt mixtures.
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