Self-healing efficiency and crack closure of smart cementitious composite with crystalline admixture and structural polyurethane

The crack closure and self-healing efficiency of smart self-healing cementitious composite can effectively reveal the mechanism of self-healing performance recovery. This study focused on effects of crack healing on crack closure and mechanical performance recovery of crack-healed cementitious composite, including flexural compressive behaviours. Meanwhile, several parameters were defined to quantify the efficiency of mechanical performance recovery efficiency for self-healing cementitious composite. Furthermore, the interfaces between self-healing products and crack surface were analyzed and compared to provide understanding insight to the self-healing recovery. It is found that the bonding interface dominated the flexural strength recovery, and therefore autonomous self-healing yielded the maximum self-healing efficiency. On the other hand, the stiffness damage recovery index under compression is found to be an effective parameter to evaluate the inner crack healing, which slightly depends on the bonding interface. The related results indicate that the development of smart self-healing cementitious composite should consider the bonding between self-healing product and crack surface to improve the self-healing recovery efficiency for engineering application. (C) 2020 Elsevier Ltd. All rights reserved.