Interaction between matrix crack and circular capsule under uniaxial tension in encapsulation-based self-healing concrete

This paper investigates the fracture process of a capsule when subjected to uniaxial tension in encapsulation-based self-healing concrete. A circular capsule embedded in the mortar matrix is considered along with different ratios of core-shell thickness. To represent potential cracks, zero thickness cohesive elements are pre-inserted throughout element boundaries. The effects of fracture strength around the interfacial transition zone of the capsule are analyzed. The crack nucleation, propagation, and fracture mode of capsule are also discussed. The numerical results indicate that increasing the strength of the interfacial transition zone around the capsule can increase the load-carrying capacity of self-healing concrete. Moreover, given a similar fracture strength around the interface of the capsule, the fracture probability of capsule in encapsulation-based self-healing concrete is strongly dependent on the core-shell thickness ratio..