Punching Shear Strength of Slabs and Influence of Low Reinforcement Ratio

Presented in this paper are the punching shear tests of 12 high strength concrete slabs (fc′ > 100 MPa [14,500 psi]) with various flexural reinforcement ratios from 0.28 to 1.43% and supported on columns having various aspect ratios of 1 x 1, 1 x 3, and 1 x 5. The resulting test data were also used to verify the suitability of the ACI 318 and Eurocode 2 punching shear equations, especially for slabs with low reinforcement ratios. Other influencing factors such as concrete strength and size effect were also addressed. The authors’ new experimental results will be combined with 355 existing published data and together they will be used to evaluate the accuracies and safety of the ACI 318 and Eurocode 2 methods for punching shear, as well as some methods proposed by other researchers. A new general method and a simplified method are also proposed; they are shown to be accurate and reliable.NRF (Natl Research Foundation, S’pore)Published versio