A state-of-the-art review and prospectives on the self-healing repair technology for asphalt materials

This paper summarizes the important research results of self-healing technology of asphalt materials, analyzes the healing mechanism of self-healing technology, and emphatically introduces the research status, advantages and disadvantages of five advanced self-healing technologies: Electromagnetic induction heating (EIH) technology, Microwave induction heating (MIH) technology, Photorepair method, Microcapsule method, and Hollow fiber (HF) method. The results showed that the existing self-healing mechanism is mainly based on surface energy theory, molecular diffusion theory and capillary flow theory, which explains the self-healing phenomenon of asphalt from different scales. The existing self-healing technology has developed rapidly, and the indoor research proves that the potential of MIH technology is higher than that of EIH technology. The repair potential of HF method is higher than that of microcapsule technology, but its material synthesis is more complicated. Photorepair technology has the potential to cooperate with other technologies, and it needs to be reasonably matched and selected. At the same time, the progress of related self-healing construction machinery and technology may require the continuous efforts of researchers. In addition, the organic synergy between different selfhealing technologies may be a feasible way for self-healing technology to move from experimental section to practical application. In the future, a set of self-healing system with strong repair effect, environmental friendliness and reasonable cost can be established from the organic synergy of various self-healing technologies, combined with life cycle cost and intelligent sensors.