Experimental study on the dynamic splitting tensile properties of polyvinyl-alcohol-fiber-reinforced cementitious composites

In this study, the dynamic splitting performance and energy absorption capacity of polyvinyl- alcohol-fiber-reinforced engineered cementitious composites were studied using a split Hopkinson pressure bar system. By using a high-speed camera, changes in the surface strain fields and crack expansion patterns of specimens under different striking pressures were observed and validated, and experimental results for four types of fiber-reinforced concrete and one type of plain concrete without PVA fibers were obtained. The strain-rate effect on the dynamic tensile strength of fiber-reinforced concrete and plain concrete was confirmed. Digital image correlation measurement results indicate that microcracks were present near the radial primary cracks in the fibrous concrete, where strain concentration zones were formed. Additionally, PVA fibers can effectively reduce the rate of decline following the peak in the localization factor, and the PVA fibers begin to play a bridging role following the generation of microcracks, which slows the damage development of specimens, allowing them to absorb more impact energy.