Crystalline Admixtures for Autonomous Healing in Concrete: The Past, Present and Future

Abstract

The development of chemical admixtures for concrete used marked a significant milestone in construction industry, and they have now become an essential component in modern concrete, due to the capability of designing desirable fresh and hardened properties. The effects on the latter, particularly durability, is important as it allows longer structural service life and hence lower associated environmental impact. However, concrete is prone to crack formation which threatens its durability. One way of dealing with this issue is to impart autonomous healing ability in concrete through the use of crystalline admixtures for repairing or sealing microcracks fully by the concrete itself. This paper provides a comprehensive overview on the past and current research on the autonomous healing in concrete using crystalline admixtures, studying the types, mechanism, performance and technology involved. The research gap and potential limitations are discussed to support future development in this area.