Dynamic chemistry approach for self-healing of polymer-modified asphalt: A state-of-the-art review

With the development of long-life asphalt pavement, it has attracted considerable attention to improving the durability of pavement engineering materials. An effective action is the use of polymer modifiers or external assistance for compositing self-healing asphalt materials. Polymer-modified asphalt using dynamic chemistry has progressed in recent years, bringing significant benefits to self-healing owing to its compelling features of reversible structures, diverse types, and environmental friendliness. With a comprehensive review of self-healing mechanisms using dynamic chemistry, the healing archetypes and factors affecting the performance recovery of asphalt modified by self-healing polymers are clarified. The synthesis, structural reversibility, and potential impact on asphalt modification of self-healing polymers are discussed. Meanwhile, the classification of self-healing polymer-modified asphalt, methods of self-healing performance evaluation, environmental impacts, and cost efficiency are summarized to promote dynamic chemistry application for self-healing asphalt fields. Furthermore, the challenges and development direction are emphasized for the development of self-healing polymer-modified asphalt materials. It is anticipated that the dynamic chemistry approach for self-healing of polymer-modified asphalt will present a novel perspective in asphalt pavement for intrinsic repair, lifetime extension, and sustainability.