Abstract:
A quasi-static punching test was conducted on polyvinyl alcohol (PVA) fiber/cementitious composite slab by using MTS testing machine. The effects of the PVA fiber content on the failure mode and bearing capacity of PVA/cementitious composite slab were studied based on the experimental results. The results show that incorporating of PVA fiber can change the failure mode of the PVA/cementitious composite slab from brittle failure to ductile failure. And both the punching capacity and the energy absorption capacity of the PVA/cementitious composite slab increase with the fiber content and more obvious rise can be observed for the energy absorption capacity. Then the dynamic punching test of PVA reinforced cementitious composite slab with 2vol% volume fraction of PVA was carried out by using Instron drop-weight impact system. The influences of the impact velocity (2.0–4.2 m/s) on the failure mode, cracking impact loading, ultimate impact loading, initial stiffness and energy absorption capacity of the PVA/cementitious composite slab were investigated. The results show that compared with the results from the quasi-static test, the ultimate loading of the PVA/cementitious composite slab increases while the energy absorption capacity decreases under the punching force. Also, a more significant increase in ultimate loading with the loading velocity can be observed, compared with that of the energy absorption capacity. A qua-linear tensile constitutive model of fiber reinforced cementitious composite was constructed based on these experimental results, and the punching mechanic behavior of the fiber reinforced cementitious composite slab was simulated by the back-calculation model based on the plastic hinge method, and the material parameters of the fiber reinforced cementitious composite were obtained. This study can provide a solid base for the punch performance design of the PVA/cementitious composite slab.