Slab–column connection punching and ductility improvement methods for seismic response of buildings with flat slabs

Replicating boundary conditions of slab–column connections under seismic loading in a realistic manner is difficult, and different test setups have been used throughout the years. An innovative test setup has been developed at NOVA School of Science and Technology, and it has been used to test various punching shear behavior enhancement methods, including stirrups, headed studs, fiber-reinforced concrete (FRC), high-strength concrete (HSC), and post-installed bolts under similar conditions. The aim of this paper is to compare the results from these different solutions for seismic loading. It is shown that relatively large drift ratios at failure can be achieved in slabs containing shear reinforcement. However, less conventional methods such as FRC and HSC are shown to be promising alternatives. Compared to reference specimens that failed at 1% drift, the other specimens with various enhancement methods achieved significantly higher drifts, ranging from 2.5% to above 6.0%.