New Approach for Punching Shear Capacity Prediction of Fiber Reinforced Polymer Reinforced Concrete Flat Slabs

A new approach predicting the punching shear capacity of FRP reinforced concrete flat slabs without shear reinforcement is introduced in the light of the results of an experimental program conducted at the Center for Cement and Concrete of the University of Sheffield. The new approach is found to accurately predict the punching shear capacity of the tested slabs. Verification of this new approach is undertaken through comparisons with other test results ensuring its validity. Comparisons of the new approach with the ACI 318-95 equation calculating the punching shear capacity of reinforced concrete slabs without shear reinforcement show that the current ACI equation is unconservative in case of FRP reinforcement with low reinforcement ratios. A modification is proposed to the current ACI 318-95 code equation for punching shear in order to accommodate low stiffness FRP reinforcement. Comparisons with test results show that the proposed modification of the ACI code equation leads to good predictions.