Effect of Healing Conditions on Fatigue-Healing of Asphalt Binder and Asphalt Mixture

Abstract

To study the effects that healing conditions have on the fatigue-healing properties of asphalt materials, we conducted a fatigue-healing-fatigue test on asphalt materials using a dynamic shear rheometer and four-point bending-fatigue-testing machine. We analyzed the changes in the fatigue-healing properties of the asphalt materials with exposure to different healing conditions. The results showed that the fatigue-healing performance of the styrene butadiene styrene (SBS)-modified asphalt and asphalt mixture was better than those of the #70 asphalt and asphalt mixture. Increases in the healing temperature, within a certain range, promoted the healing of the asphalt mixture. Excessive temperatures led to asphalt aging and inhibited healing. The optimal healing temperatures for the #70 asphalt and SBS-modified asphalt mixtures were 50°C and 60°C, respectively. Extending the healing time was beneficial to healing. The healing efficiency decreased with an increase in the healing time. The most effective healing times for the asphalt binder and asphalt mixture were approximately 30 min and 12 h, respectively. We do not advise the excessive prolongation of the healing time to pursue a 100% healing recovery.