Evaluation of self-healing characteristics of asphalt materials by intermittent loading tests

A self-healing index, recovery modulus ratio (RG), was proposed to evaluate the self-healing characteristics of asphalt materials with intermittent loading tests which is more consistent with the traffic loading. In this study, three types of asphalt binders and six types of asphalt mastics were performed on intermittent loading tests. Based on the test results, RG was demonstrated to be a suitable self-healing index for evaluating the effect of filler-asphalt ratio and stress level on the self-healing performance of asphalt materials, and there was a linear positive relationship between it and the growth rate of fatigue life. A higher asphalt-filler ratio deteriorates the self-healing performance of #70 asphalt mastic. However, there is an adverse impact on the harder #50 asphalt mastic. The higher stress level worsens the self-healing performance of base asphalt; however, it has an advantageous influence on SBS modified asphalt within a certain stress level range.