Behavior of Composite Beam-Column Joints in a Middle-Column-Removal Scenario: Experimental Tests

Abstract

A series of experiments has been conducted to investigate the failure modes and ductility of composite beam-column joints in a middle-column-removal scenario. Composite web cleat and flush end plate connections were studied. The research included two types of tests: namely, middle joints under a sagging moment and side joints under a hogging moment. Five composite beam-column joints with reentrant steel profile decking were tested. The contributions from two types of mechanisms (namely, flexural action and catenary action) have been identified. The main objective of the experimental program is to study the behavior of composite joints in a middle-column-removal scenario. The test results demonstrate the ductility and load resistances of these five specimens in catenary action mode, and indicate that at the initial loading stage, the applied load was resisted by flexural action, while at the large deformation stage, the load was resisted by catenary action. It is also found that composite slabs could increase the load-carrying capacities of beam-column joints at both the flexural action and catenary action stages. The strengthened web cleat connection has a much higher load-carrying capacity than the normal web cleat connection because the former could sustain greater deformation.