Experimental research was conducted to investigate the punching shear performance of flat plates. A large number of slab specimens of normal- and high-strength concrete were tested Under concentric and eccentric loads. The effects of flexural reinforcement and the use of steel fiber reinforcernent were investigated. Experimental expressions werw developed for the computation Of residual slab strength. Experimentally observed punching, shear capacities were compared with those from the provisions of Canadian Standards Association (CSA) standard CSA-A23.3-04. The results indicate that concrete strength plays all important role ill punching capacity and slab rigidity. Slabs with a higher percentage of flexural reinforcement show in increase ill Punching capacity. The use of steel fibers results in improved strength and stiffness while also enhancing the postpeak deformability and residual strength. The empirical expressions developed provide reasonably good predictions of residual Slab capacities. CSA-A23.3-04 expressions result ill conservation punching shear capacity predictions for concentrically loaded slabs and provide good agreement with the experimentally observed punching shear capacities for eccentrically loaded slabs.