This study investigated the effect of nano montmorillonite at different damage degree on the multiple self-healing properties of asphalt mixture by semicircular bending (SCB) test. Four kinds of asphalt binder were used to prepare the asphalt mixture. The cumulative fatigue life was measured and the multiple healing index (MHI) was proposed as an index to evaluate the multiple healing. The test results of different healing temperatures and damage degrees were fitted to obtain the threshold conditions of multiple self-healing. The fatigue life of asphalt mixture was evaluated by four-point bending beam test. Results showed that montmorillonite (MMT) could improve fatigue resistance and the self-healing ability of asphalt mixture, especially when the damage degree was small. The multiple healing capacity of the mixture decreased with the increased of the degree of damage. After freezing-thawing cycle, the self-healing ability decreased significantly. In addition, the results of multivariate nonlinear fitting showed that when the damage degree of montmorillonite modified asphalt mixture was less than 30% and the ambient temperature reaches 50°C, multiple times of self-healing can be effectively achieved. The fitting results can also be used to calculate the self-healing threshold conditions of other asphalt mixtures.

本研究通过半圆弯曲（SCB）试验研究了不同损伤程度的纳米蒙脱石对沥青混合料多重自愈性能的影响。四种沥青结合料用于制备沥青混合料。测量累积疲劳寿命并提出多重愈合指数(MHI)作为评价多重愈合的指标。对不同愈合温度和损伤程度的测试结果进行拟合，得到多重自愈合的阈值条件。沥青混合料疲劳寿命采用四点弯曲梁试验进行评价。结果表明，蒙脱石(MMT)能提高沥青混合料的抗疲劳性能和自愈能力，尤其是在损伤程度较小的情况下。混合物的多重自愈能力随着损伤程度的增加而降低。冻融循环后，自愈能力明显下降。此外，多元非线性拟合结果表明，当蒙脱石改性沥青混合料损伤程度小于30%，环境温度达到50℃时，可有效实现多次自愈。拟合结果也可用于计算其他沥青混合料的自愈阈值条件。可有效实现多次自愈。拟合结果也可用于计算其他沥青混合料的自愈阈值条件。可有效实现多次自愈。拟合结果也可用于计算其他沥青混合料的自愈阈值条件。