High-temperature tests on joints to steel and partially-encased H-section columns

This paper reports on a series of tests at elevated temperatures on connections between steel beams and H-section columns, both unfilled and partially-concrete-encased. Reverse-channel connections to both types of column, as well as flush endplate connections to partially-encased H-section columns, were studied. The experiments aimed to investigate the behaviour of beam-to-column connections subject to significant tying forces and large rotations in fire situations, and to provide test data for development and validation of simplified component-based connection models. It has been found that reverse-channel connections provide not only high strength, but also the high ductility which is required to reduce the possibility of connection fracture and to improve the robustness of buildings in fire.

► Reverse-channel (RC) connections provided both high strength and high ductility.
► Such high ductility may reduce the possibility of connection fracture in fire.
► Use of RC connections may improve the robustness of buildings in fire.
► The failure of RC connections was controlled by the channel web.
► Use of thick endplates enhanced ultimate strength but significantly reduced ductility.