| Summary: | Progressive collapse in buildings has occurred on numerous occasions throughout human history. Notable events of progressive collapse include the 911 incident and the Ronan Point collapse. The disproportionate nature of progressive collapse can be mitigated using alternate path method but such methods prescribed by existing codes lack the consideration of catenary action. This study aims to understand the behaviour of composite web cleat connection subjected to a missing column scenario. Experiments had been carried out in the Laboratories in Nanyang Technological University to investigate such behaviour and its significance as part of a 2-D frame. It is found that composite web cleat beam-to-column joints were able to mobilize catenary action to resist vertical loading. In addition, it is observed that the joint behaviour in hogging and sagging moment regions exhibit different failure modes due to the difference in the lever arm between the compression and the tensile elements. It is noteworthy that the joint ductility which governs the mobilization of catenary action is controlled by the critical components of the joint, and the ductility and strength of such components have a direct influence on the connection behaviour. The report highlights the relevant behaviour of composite web cleat beam-to-column joints to the activation and formation of catenary action to mitigate progressive collapse. In addition, a component based model has been formulated to predict the behaviour of composite web cleat beam-to-column joints under a missing column scenario.
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