Accelerating autonomic healing of cementitious composites by using nano calcium carbonate coated polypropylene fibers

Fibers can enhance self-healing of concrete by restricting crack propagation and supplying nucleation sites in cracks. To further improve the effect fiber concrete, a new strategy modification for is proposed herein. In this study, polypropylene (PP) fibers were coated with nano calcium carbonate as seedings ethyl cellulose film protective layer. The layer inhibit interactions cement matrix before cracking. While after mortar mixing cracking, was gradually removed due to shear stress friction during pull-out cracking processes, respectively. With elimination layer, remaining coating at around 5.6 % mass could be exposed cracks, thereby accelerating healing product generations hydration precipitation, which verified scanning electron microscopic observations, Fourier-transform infrared spectroscopy thermogravimetry analysis. Owing effects modified fibers, closure 300–500 μm wide cracks enhanced 100 recovery water tightness subsequently achieved.