Punching Tests on Reinforced Concrete Slabs with and without Shear Reinforcement

摘要

The results of punching tests carried out at the Swiss Federal Institute of Technology (ETH) in Zurich, Switzerland, on three full-scale reinforced concrete slab specimens are presented and discussed. The main focus is on the punching failure modes obtained with different shear reinforcement arrangements and their corresponding failure loads. One of the 350 mm (13.8 in.) thick specimens had no shear reinforcement (Specimen SP1), whereas the other two were reinforced with double-headed shear studs, which were placed locally around the column (Specimen SP2) or over the entire slab (Specimen SP3). The three failure modes-punching without shear reinforcement, punching outside the shear-reinforced zone, and punching within the shear-reinforced zone due to concrete crushing-were observed. The experimental failure loads ranged from 43 to 85% of the computed ultimate flexural load of the specimens. All three failure modes were correctly predicted by the pertinent ACI 318-08 and EC2 Code provisions, as well as by the critical shear crack theory (CSCT). Further, it is shown that the load-deflection behavior of the slabs can be computed with a bending approach.