沥青混合料低温抗裂性能研究

以低温弯曲试验为基础,得出沥青混合料破坏能的函数关系。采用Burgers模型作为本构模型,对低温弯曲蠕变试验结果进行非线性分析,得出材料模型的粘弹性参数。通过模拟路面降温条件,采用粘弹性方法以Burgers模型为基础得出温度应力的计算公式,以及温度应力产生的应变能的计算方法,进而以能量为判据,提出将温度应力产生的应变能与沥青混合料的破坏能相比较,从而判断沥青路面是否发生低温开裂的预估方法。

Study on Thermal Crack of Asphalt

Based on the low temperature test data,this paper gave out the function of failure energy for asphalt.Then the authors adopted Burger's model as the constitute model to analyse the low temperature creep test data,and obtained the visco-elastic parameters of the constitute model of asphalt by non-liner least square techniques.According to simulating the drop of asphalt pavement temperature,the authors obtained the temperature stress formula based on the Burger's model by visco-elastic analysis and the boundary conditions.Then the authors put forward a method to evaluating the thermal crack of asphalt pavement by using energy as the criterion to evaluate if the asphalt pavement would crack or not under low temperature.That is,when asphalt pavement temperature dropped,temperature stress arising in the pavement that produced strain energy.If the strain energy was larger than the failure energy of asphalt it,the thermal cracking would occurr in the asphalt pavements.