ABSTRACT
This study presents a 3D coupled chemo-mechanical finite element model for the simulation of the damage-healing behaviour of cementitious materials with embedded vascular networks. The mechanical damage-healing behaviour is described using a cohesive zone model that is implemented into an embedded strong discontinuity element. The mechanical model allows for damage and healing to occur simultaneously, and places no restrictions on the number of damage-healing events. An important feature of the damage-healing model is the inclusion of a healing strain that ensures thermodynamic consistency when healing takes place in non-zero strain conditions. The mechanical model is coupled to a reactive transport model that describes the transport of healing agent to the damage site, along with the chemical reaction governing crack healing. The model considers the reactive transport of healing agent within the discrete cracks, the surrounding cementitious matrix and the embedded vascular network. Richard’s equation describes the matrix flow, which is coupled to the mass balance equation combined with Darcy’s law for the flow in the discrete cracks and embedded vascular network. For the crack and embedded vascular network flow, a cut finite element framework is employed that allows for discontinuities, such as those found at the fluid interface, internal to the elements. The performance of the model is demonstrated through comparison to data from an experimental investigation undertaken at Cardiff University. The results of the comparison show that the model is able to predict realistic transport of healing agents, as well as being able to represent the damage-healing behaviour with good accuracy.
