Abstract
In order to study tensile failure in fiber-reinforced concrete, split-tensile tests were conducted. Disc-shaped samples of mortar, plain concrete, steel-fiber reinforced concrete (SFRC) and polyvinyl-alcohol-fiber reinforced concrete (PVAFRC) were tested. Fracture mechanisms at the meso-scale are identified by applying SiGMA (Simplified Green’s functions for Moment tensor Analysis) procedure of acoustic emission (AE). In fiber-reinforced concrete, a self-healing draws an attention in concrete engineering. The effect could bridge opened (tensile) cracks due to hydration of unreacted cement. Since the crack width of the tensile crack is a key issue, kinematical information of the crack formation process is investigated in the split-tensile test prior to experimental confirmation on the self-healing effect. It is found that sliding motions on the crack surface are more dominantly observed in PVAFRC than those in mortar, plain concrete and SFRC, prior to reaching the final stage, i. e. possibly under the service load. This suggests that self-healing products, which could be generated at the cracked surface, could play the more effective role in PVAFRC for bridging meso-scale cracks due to tight spaces (gaps) across fibers.
