Comparison between different strengthening schemes for punching shear of flat plate slabs

This study presents a finite element model that is developed to examine various FRP strengthening schemes to mitigate the punching shear failure of flat plate slabs. In this study, nonlinear material behaviour of the plain concrete, steel reinforcing bars and FRP composites are simulated with appropriate constitutive models and structural elements. The accuracy of the model is established through comparing the finite element predictions with existing experimental results. Once the accuracy of the model is accepted, it is employed to investigate various FRP parameters that may influence the punching shear failure of flat plate slabs. Thirty six models are carried out to investigate the following parameters: (a) width of FRP strips; (b) thickness of FRP strips, and (c) length of FRP strips. The schemes considered include various numbers of strips around the column, and FRP strips with low, medium and high strengths. Numerical results are presented in terms of ultimate punching shear capacity and load-deflection relations. In light of results obtained, the scheme and mechanical properties of FRP strips around the columns reduces the length of the strip required to achieve the ultimate punching capacity.