Full-scale tests on shear connections of composite beams under a column removal scenario

Abstract

In this research, the progressive collapse behaviour of a shear connection of a composite beam has been investigated experimentally. Steel shear/simple connections are widely used in composite gravity framing systems and their behaviour under conventional loading is well understood. However, their response and robustness under the column removal scenario is still largely unknown. While the slab itself can participate in maintaining the integrity of the overall floor system, its presence also amplifies the demand on the steel connections after experiencing initial flexural action. As the column pulls down progressively, which results in a large vertical deflection, the shear connection reaches its capacity under tension-dominant action. The contribution of the concrete slab to the steel connection demands plays an important role in determining the failure mode, load carrying capacity, and ductility of the connections. The main objective of the experimental program is to study the behaviour of steel shear connections in the presence of a concrete slab under a column removal scenario. The test results show the performance of the connection in terms of rotational ductility and ultimate load capacity.