Damage-healing analysis of microencapsulated self-healing concrete subjected to tensile loading using a 2D micromechanical model

Self-healing concrete that employs microencapsulated healing agents has been proven to be an effective method for microcrack repairment in the concrete structure. However, there is a lack of efficient tools to evaluate the effect of the parameters of microcapsules on the mechanical behavior of the self-healing concrete. In this paper, the evolution of the damage-healing process of microencapsulated self-healing concrete subjected to tensile loading is numerically analyzed from a microscopic perspective by using a 2D micromechanical model. Based on the deformation and propagation evolution mechanism of microcracks, the contribution of microcracks to the total compliance tensor of microencapsulated self-healing concrete under tensile loading is deduced at various stages. According to the calculated total compliance tensor, the stress-strain and compliance-strain relations of microencapsulated self-healing concrete are discussed with special attention to the stress dropping and strain softening stages. Finally, parametric analysis was conducted using the constructed model to investigate the influence of size and content of microcapsules, the types of healing agent and the initial damage of the concrete on the mechanical behaviors of microencapsulated self-healing concrete. The constructed 2D model is significantly useful for the reasonable selection of the optimal parameters of microencapsulated self-healing concrete.