Autogenous healing and its enhancement of interface between micro polymeric fiber and hydraulic cement matrix

This study examines autogenous healing of interface between micro polymeric fiber and hydraulic cement matrix. Experiments were carried out to evaluate the healing-induced recovery of fiber/matrix interface bond strength and to characterize the morphology and chemical compositions of the healing products. Results show that interface frictional bond strength is significantly recovered after eight cycles of water/air conditioning. The healing products are mainly CaCO₃ which has a crystal-like morphology with a particle size of 0.5–2 μm. Fiber/matrix interface healing results in significant recovery of fiber-bridging strength of pre-cracked FRCC. Furthermore, inclusion of fly ash in the mix composition remarkably enhances the autogenous healing of fiber/matrix interface as the healing degree of interface frictional bond strength increases from 63% to 94% and that of the fiber-bridging strength improves from 82% to 127%.