Evaluation of compressive membrane action effects on punching shear resistance of reinforced concrete slabs

It is widely recognized that Compressive Membrane Action (CMA), also called Arching Action, increases both the bending and punching capacities of reinforced concrete (RC) structures. In this paper a non-linear finite element (NLFE) approach which adopts multi-layered shell modeling of RC slabs is presented. NLFE analyses (NLFEA) were carried out with ABAQUS Code and UMAT.for user subroutine in which the crack model denoted as Physical Approach for Reinforced Concrete for Cyclic Loading (PARC_CL) was implemented. Post-processing of NLFEA results is presented which exploits the Critical Shear Crack Theory (CSCT) to evaluate the punching shear resistance of shell elements. The capability of the proposed numerical procedure, to properly determine the punching shear resistance of RC slabs, is checked by comparing numerical predictions with experimental punching shear capacities obtained on circular slabs tested at the Stevin Laboratory of TU Delft. Subsequently the same numerical procedure was adopted to evaluate CMA effects on the punching shear resistance of the Corick bridge deck in Northern Ireland, UK, subjected to concentrated loads. Finally the design punching shear resistances achieved with the presented procedure are compared with the analytical values obtained using the British Code BD81/02.