Effect of Healing Agents on Crack Healing of Asphalt and Asphalt Mortar

Abstract

This study investigated the effect of seven healing agents on crack healing ability of long-term aged asphalt and its mortar. Different healing agents including sunflower oil, aromatic oil, bitumen emulsion, and maltene-based emulsions were used. The crack healing of asphalt made use of two asphalt disk samples and healing was evaluated using direct tensile tests. For asphalt mortar, notched semi-circular samples were used. Test results indicated that the crack healing of asphalt and its mortar depended strongly on the type of healing agent. In general, asphalt healed faster than its mortar. Asphalt healing could be well improved by using oil agents, while asphalt mortar could be well healed with maltene-based emulsions. The crack healing of asphalt mortar developed rapidly followed by a steady state of increase. Initial crack healing using healing agents could be contributed by the diffusion and softening effects, which resulted in low strength recovery. Long term healing could lead to the bonding reconstitution in the cracks, which were decisive for the final strength gain. The promising healing agent should be able to achieve maximum strength recovery to resist cracking as well as a sufficient re-healing ability to deal with crack opening and closing.

Influence of Microcrack Healing Techniques on Tensile Strength of Asphalt

“…It is concluded that self-healing efficiency of asphalt concrete can be enhanced through microwave heating. Pan et al, [4] investigated the effect of seven healing agents on crack healing ability of long-term aged asphalt and its mortar. Test results indicated that the crack healing of asphalt and its mortar depended strongly on the type of healing agent.…”

Special Issue of Environment-Friendly Construction Materials

“…In the study by Wan et al [29], self-healing properties of steel fiber and steel slag based ultra-thin wearing course were studied by a semi-circular bending test under induction heating. Other researches focused on the healing agent effect [30], induced healing efficiency of induction heating and microwave heating [31], and initial self-healing temperature [32].…”