A 3D Coupled Finite Element Model for Self-Healing Quasi-Brittle Materials

This study presents an overview of a 3D coupled finite element model for self-healing quasi-brittle materials. The model was developed alongside a linked experimental programme such that model components were formulated based on observed material behaviour and physical processes. The mechanical model comprises an embedded strong discontinuity element for representing discrete macro-cracks and a linked damage-healing cohesive-zone model. This is coupled to a transport model that simulates the reactive transport of healing agents in both discrete macro-cracks and the surrounding matrix material. For the simulation of the healing reaction that governs crack sealing and mechanical regain, a generalised healing front model is employed. The performance of the model is demonstrated through the consideration of the healing of a cementitious specimen. The results show that the model can accurately reproduce the crack filling predicted by a cement hydration model, and naturally accounts for the effect of healing period and crack width.