The behaviour of composite cold-formed steel beam-to-column joints with different shear connection type

A composite beam-to-column joint formed by a composite concrete slab and two cold-formed steel C-sections placed back-to-back as beam and column had been investigated experimentally. The experimental results are presented in this paper. Three specimens with cruciform subassemblies of cold-formed steel (CFS) beam-to-column joint and three push-out samples were tested with a novel approach to different shear connections: nut bolt, cold-formed angle, and cold-formed corrugated plate. The joints were made from CFS with an 8 mm thickness and were built using only angles from the top and seat. The results show that using a cold-formed steel corrugated plate results in a rotation capacity of 25.2 mrad, which is close to the semi-rigid connection rotation capacity limit (30 mrad). Although only the bar minimum of reinforcement is used, these joints will become semi-rigid as the proportion of steel reinforcement increases. This is extremely helpful in plastic design in composite structures. Small slips are also visible in composite joints and push-out specimens for all types of shear connections. The push-out results show that the specimen bolt shear connector has approximately 52.7 percent more strength than the specimens with angle plate and corrugated plate shear connectors. As a result, the shear connection type and degree significantly impact the composite beam-to-column connection’s behavior and rotation ability.