A two-dimensional micromechanical damage–healing model on microcrack-induced damage for microcapsule-enabled self-healing cementitious composites under compressive loading

The use of microcapsule-enabled self-healing cementitious composite has high potential as a new repair method for the cracked concrete. It will evidently provide extended lifetime and security while reducing the maintenance costs and rates of occurrences of system failures by incorporating self-healing agents in microcapsules. Based on experimental observation and Taylor’s model, a two-dimensional micromechanical damage–healing model of microcapsule-enabled self-healing cementitious materials under compressive loading has been proposed. The proposed model can predict the healing effect on microcrack-induced damage quantitatively under compressive loading. The kinetic equations of damage–healing evolution and the formulations of compliance after healing are developed. Subsequently, the proposed model is validated by experimental data. Different system parameters of microcapsule-enabled self-healing concretes, such as the fracture toughness of healing agents, the degree of initial damage, the volume fraction and radius of microcapsules, are investigated. In particular, the proposed micromechanical damage–healing model demonstrates the potential capability to explain and simulate the physical behavior of microcapsule-enabled self-healing materials under compressive loading on the mesoscale.