考虑集料沥青交互作用的沥青疲劳性能

Fatigue property of asphalt considering aggregates-asphalt interaction

为了探究集料与沥青接触条件下沥青的疲劳性能,减少预测误差,基于动态剪切流变仪(DSR),对70号石油沥青与3种类型集料基板(石灰岩、辉绿岩、花岗岩)的组合下沥青的疲劳寿命进行了测定,此外,通过直接拉伸试验探究一定膜厚范围内沥青与集料的黏结特性,分析不同组合下界面黏结特性与沥青疲劳性能之间的关系。结果表明:①不同集料接触条件下的沥青疲劳寿命存在差异,根据沥青疲劳性能对3种组合的排序为:石灰岩>辉绿岩>花岗岩。②疲劳寿命结果与直接拉伸试验结果具有一致性,原因可能是集料与沥青的化学黏附提高了界面过渡区(ITZ)沥青的力学性能,有利于沥青的抗疲劳损伤能力。

In order to study the fatigue property of asphalt in contact with aggregates and reduce the prediction errors,fatigue life of asphalt with combination of three types of aggregate substrates(limestone,diabase,granite)were measured.In addition,direct tensile(DT)test was conducted to study the bonding characteristic of asphalt and aggregate within a certain film thickness,and the relationship between interfacial bonding characteristic and asphalt fatigue property under different combinations was analyzed.Results show that there are differences in asphalt fatigue life in contact with different aggregates.According to asphalt fatigue property,three combinations are ranked as follows:limestone>diabase>granite.The results of fatigue life are consistent with those of direct tension test.This can be attributed to the fact that the chemical adhesion between aggregates and asphalt improves the ITZ mechanical properties of asphalt,which is conducive to its resistance to fatigue damage.