Influence of strain rate on mechanical characteristic and pore structure of self-healing cementitious composites with epoxy/urea-formaldehyde microcapsules

A physical triggered self-healing system was formed by mixing the epoxy/urea-formaldehyde microcapsules into cementitious materials. The effects of the microcapsule contents and strain rate on the mechanical properties, pore structure and self-healing efficiency were investigated in this study. Both the strain rate and microcapsule contents influenced the strength and pore structure. With increasing of the strain rate, the strength of specimens gradually increased. With increasing of microcapsule content, the strength of initial specimens declined to varying degree, the strength of healing specimens gradually increased. Microcapsules had an positively effects on the self-healing but negatively effects on the pore structure parameters of initial specimens. And the microcapsules also had effects of the deformations properties, and improved the brittleness characteristics of the specimens. These findings reflected the self-repairing effects of microcapsule on cementitious materials from a dynamic point of view.