Influence of continuity on punching resistance at edge columns

The paper considers punching failure at edge columns of reinforced concrete flat slabs without shear reinforcement and unbalanced moments about an axis parallel to the slab edge. Edge column punching shear tests have been carried out on a variety of isolated and continuous specimens. The influence of eccentricity and continuity on punching resistance is assessed using existing experimental data, nonlinear finite element analysis (NLFEA) and the Critical Shear Crack Theory (CSCT) as implemented in fib Model Code 2010 (MC2010). Relating punching resistance to the elastic unbalanced moment as done in MC2010 Levels I to III is shown to be overly conservative for continuous slabs. The ACI 318 and Eurocode 2 (EC2) practice of making the design punching resistance independent of the unbalanced moment is reviewed and shown to be reasonable particularly for continuous slabs