交通量非均匀分布的沥青路面疲劳等效温度

Fatigue equivalent temperature of asphalt pavement with nonuniform traffic volume distribution

针对现有沥青路面疲劳等效温度理论未考虑交通量非均匀分布和沥青路面温度取值不合理等问题,为更加准确科学地计算等效温度,提出沥青层当量温度和深度概念并推导其计算方法,建立大气日当量温度与沥青层当量温度的关系,采用沥青层当量深度处的当量温度作为沥青层代表温度并划分温度区间,开展沥青混合料动态模量和疲劳试验,统计各个温度区间内的交通量分布频率,基于Miner线性累积原理提出一种考虑交通量非均匀分布的沥青路面疲劳等效温度计算方法,计算两种交通量分布方式的等效温度值,最后与其他方法进行对比分析.结果表明:沥青层当量温度可作为沥青层代表温度来划分温度区间;考虑交通量非均匀分布的沥青路面疲劳等效温度计算方法在理论上改进了现有方法的不足,使等效温度的计算更加科学和可靠,两种交通量分布方式的等效温度实际计算结果相差1.6℃,与其他方法相比具有一定的优越性,后期应当加强观测,进一步完善计算方法的精确性.

The existing theory on fatigue equivalent temperature of asphalt pavement does not take account of the nonuniform traffic volume distribution and the values of asphalt pavement temperature are unreasonable.To calculate the equivalent temperature in a more accurate and scientific way,the concepts of equivalent temperature and depth of asphalt layer were proposed and corresponding calculation methods were deduced.The relationship between the daily equivalent temperature of atmosphere and the equivalent temperature of asphalt layer was established.Taking the equivalent temperature at the equivalent depth of the asphalt layer as the representative temperature and dividing the temperature into different ranges,the dynamic modulus and fatigue tests on asphalt mixtures were carried out,and the frequency of traffic volume distribution in different temperature ranges was classified.Based on the Miner linear cumulative principle,a method was proposed for calculating fatigue equivalent temperature of asphalt pavement that takes the nonuniform distribution of traffic volume into consideration.The equivalent temperature values of two traffic volume distribution modes were calculated and comparative analysis was carried out.Results show that the equivalent temperature of asphalt layer could be used as representative temperature to divide temperature ranges.The proposed calculation method for the fatigue equivalent temperature of asphalt pavement could overcome the shortcomings of the existing methods theoretically by taking the nonuniform distribution of traffic volume into consideration,which makes the calculation of equivalent temperature more scientific and reliable.The calculated temperature of two traffic volume distributions had a difference of 1.6°C.Compared with other methods,the proposed method had certain advantages.To further improve the accuracy of the calculation method,more intensified observation should be made in the future.