基于沥青路面温度特征的沥青混合料冻融损伤分析

iming at the serious harm to the service performance of asphalt pavement caused by the freeze-thaw damage of asphalt mixture in the alpine region of Qinghai-Tibet, the freeze-thaw damage and deterioration of asphalt pavement under real working conditions were studied through the temperature characteristics of asphalt pavement. The statistical method was used to analyze the air parameters that affect the temperature characteristics of asphalt pavement, and the temperature field model of asphalt pavement was established by finite element method to analyze the temperature characteristics of asphalt pavement. The indoor freeze-thaw cycle test was used to reveal the damage and deterioration process of asphalt mixture. Based on the temperature characteristics of asphalt pavement combined with the classification criteria of freeze-thaw intensity, it was obtained that 211 freeze-thaw times occurred in the upper layer of the asphalt surface in Nagqu in 2018, and the saturation rate reduction coefficient and freeze-thaw rate were proposed fully considering the effects of temperature and moisture in the freeze-thaw process. The reduction coefficient was used to correct the effect of indoor freeze-thaw, and the sine function was used to fit the changing trend of asphalt mixture modulus with time history under freeze-thaw effect. The research shows that the freeze-thaw effect has a significant impact on the mechanical properties of the asphalt mixture. The compressive rebound modulus of the asphalt mixture decreases by 28% within 6 years, of which it decreases by 17% in the first year, and then the attenuation amplitude decreases year by year. The study is as follows: Provide reference for maintaining and improving the performance of asphalt pavement in the alpine region of Qinghai-Tibet.