Effects of self-healing mechanism on the fatigue life of recycled asphalt mixes

Abstract

This study analyzed how the self-healing potential of recycled asphalt mixtures with varying levels of RAP (0%, 10%, 30%, and 50%) affects its fatigue resistance. To achieve this objective, the specimens were subjected to controlled tensions corresponding to 25%, 50%, and 75% of the fatigue life determined through Indirect Tensile Fatigue Test (ITFT). Subsequently, self-healing was induced. This process involved heating the confined specimens to 45 °C for 4 h, followed by 24 h of rest at an ambient temperature of 25 °C and then carrying out ITFT tests until rupture. After testing, it was possible to quantify the self-healing index and the percentage of extension on the fatigue life achieved post-self-regeneration. The results indicate that increased RAP content leads to more significant difficulties in mobilizing asphalt binders to seal cracks, resulting in reduced self-healing capacity. However, when self-healing occurs at a lower damage level in RAP-containing mixtures, a substantial increase in fatigue life may occur. As a result, the self-regeneration process plays a subtle yet significant role in extending the lifespan of pavement. This effect is particularly effective in rectifying minor damages caused by traffic-induced stresses.