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

Concretes with micro-encapsulated healing agents are very appealing due to the advantages of self-healing and the potential for controllable quantifiable healing on a large scale with little initial damage. Based on experimental observation and Taylor's model, a two-dimensional micromechanical damage-healing model of microcapsule-enabled self-healing cementitious materials under tensile loading has been proposed. The healing effect on microcrack-induced damage can now be predicted quantitatively by its microscopic healing mechanism. The kinetic equations of damage-healing evolution and the formulations of compliance after healing are developed. Subsequently, simple and efficient numerical simulations are presented and different system parameters of microcapsule-enabled self-healing concretes, such as the radius and volume fraction of microcapsules, fracture toughness of healing agents and initial damage degree, 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 on the mesoscale.