Effect of incompatibility between healing agent and cement matrix on self-healing performance of intelligent cementitious composite

Abstract Encapsulation-based intelligent self-healing cementitious composite with a potential of crack self-healing and closure is promising to recovery concrete from damage and improve the durability and serviceability of infrastructures. The efficiency of self-healing concrete were investigated, but limited studies have been conducted on effect of incompatibility between the self-healing agent and cement matrix on the cracking behaviour and recovery efficiency of crack-healed concrete. In this study, a coupled experimental and numerical investigations were adopted to understand the cracking behaviours of crack-healed cementitious composites using traction–separation law by extended finite element method (XFEM). Firstly, experimental investigation was conducted to characterize the properties and parameters of cement matrix and healing agent-crack interface to calibrate the traction–separation law. Then, various parameters of healing agent, cement matrix, and their interface on the performance of crack-healed cementitious composite was numerically analysed. The results indicate that to achieve excellent self-healing performance, it is vital to consider the incompatibility between healing agent and cement matrix in the design of intelligent self-healing cementitious composites.