The effects of partial shear connection in the hogging moment regions of composite beams. Part 1: Experimental study

An extensive experimental programme has been conducted to investigate the behaviour of eight composite beams subjected to hogging moment. The test specimens were designed to represent the primary internal joints of a typical low to medium-rise sway frame with loading effects that simulate wind or moderate earthquake conditions in Australia. Three of the beams were subjected to uni-directional, static loading and the remainder were loaded under constant-range, quasi-static cycles. Parameters including the level of shear connection and percentage of reinforcement were varied. The results produced very encouraging signs for the application of partial shear connection (PSC) design within the hogging moment regions of continuous and semi-continuous composite structures. This could be beneficial for plastic design purposes. No significant difference in the ultimate load capacity was exhibited in beams designed with lower degrees of shear connection. However, an enhanced ductility was observed by the increase in rotational capacity. The prescribed repeated loads also had negligible ramifications on the performance of the beams. A companion paper is included which considers the non-linear material response of these beams and also provides a modified rigid plastic analysis approach to consider the effects of PSC.