Fabrication, characterization and assessment of the capsules containing rejuvenator for improving the self-healing performance of asphalt materials: A review

The intrinsic self-healing efficiency of asphalt pavement is insufficient to timely repair the cracks generated due to the asphalt aging, traffic loading, and other unfavorable factors. Hence, the possible solutions to promote the self-healing process of asphalt have been extensively explored by scholars in recent years. This review introduces the asphalt self-healing phenomenon, mechanism and enhancement methods, elaborates the fabrication methods of the capsules encapsulating asphalt rejuvenator, and further analyzes the characteristics of the capsules by the surface morphology, internal structure, chemical composition, thermal stability and mechanical strength. Finally, the assessment of the capsules is made in view of their effects on the self-healing property and the road performance of asphalt materials. It is found that the capsules have great differences in the physical and chemical properties that are mainly affected by the materials used and the encapsulatioin methods. All the capsules have certain abilities to improve the self-healing performance of asphalt, but the improvement degree varies significantly with the test specimen, test method, healing condition and evaluation indicator. Meanwhile, the road performance of asphalt mixture with an appropriate content of capsules can still meet the requirements. This review provides support for the improvement of asphalt self-healing performance and the construction of smart pavements. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

This review discusses the possible solutions to promote the self-healing process of asphalt and the impact of capsules on the self-healing performance and road performance of asphalt. It is found that capsules have the ability to improve the self-healing performance of asphalt, but the degree of improvement varies significantly depending on various factors.