Efficient approaches to autogenous and autonomous self-healing concrete: a review

Concrete and cementitious composites have far been the main and most widely used construction materials throughout the world due to their outstanding features, such as high structural properties, accessibility and relatively low production costs. However, these materials are prone to degradation caused either by automatic cracking or external excitations, which leads to structural degradation. The increasing concern for maintaining safety and enhancing durability of cement composite structures has led to the development of several smart self-healing techniques by researchers. Regarding the diversity of these methods, this study aims to provide a comprehensive review of state-of-the-art technologies in self-healing concrete. For this purpose, the methods are divided into two general categories: autogenous and autonomous self-healing, each of which are subdivided into different methods. The basic principles and influencing factors as well as the main advantages and challenges of these techniques are discussed. Finally, general conclusions are drawn and some suggestions for future advances are presented.