沥青混合料动态模量季节性变化规律研究

Research on Seasonal Variations for Dynamic Modulus of Asphalt Mixtures

路面结构中沥青混合料的实际工作温度是一个很宽的范围,为了更客观地进行路面结构的分析和设计,需要确定混合料力学性质随时间的变化情况。通过试验确定了某一柔性基层沥青路面试验段各层沥青混合料的动态模量主曲线和时间温度转化因子,并利用实测的2002—2003年每1 h的气候数据分析了试验段温度场的分布及变化情况,进而确定了路面结构内不同深度处沥青混合料动态模量随时间的变化情况,可供路面结构分析和设计参考。分析结果表明,沥青混合料的动态模量呈现出明显的季节性变化,最大、最小日平均动态模量可相差14倍以上,随着深度的增加,动态模量的季节性变化幅度逐渐减少。

The working temperature of asphalt mixtures in pavements was in a wide range. Thus, the variations of mechanical properties of asphalt mixtures with time have to be determined to more realistically analyze and design pavement structures. In this study, the dynamic modulus master curves and time-temperature shift factors of asphalt mixtures used in an asphalt pavement with flexible base were determined based on laboratory test results, and temperature distributions and changes within the pavement were predicted from hourly climatic data collected in 2002 and 2003. Variations of dynamic modulus of asphalt mixtures at different depths in the pavement were analyzed. The data provided in this study could be useful for analysis and design of pavements. The results indicated that the dynamic modulus of asphalt mixtures shows significant seasonal variations, and the ratio of maximum and minimum daily average dynamic modulus could reach above 14. Seasonal variation amplitude decreases as depth increases.