Experiments on reverse-channel connections at elevated temperatures

This paper reports on an experimental investigation of the behaviour of reverse-channel connections between steel beams and concrete-filled tubular (CFT) columns in fire conditions. The objectives of the tests were to assess the behaviour of beam-to-column connections subject to the combinations of significant tying and shear forces and large rotations, which can arise during a building fire, and to provide test data to characterise and validate simplified temperature-dependent component-based connection models. It has been found that the reverse-channel connections not only provide a practical solution for connecting steel beams to composite columns but they also possess high ductility and strength. Such high ductility allows greater beam deformations in fire while reducing the magnitudes of the induced axial forces, thereby enhancing the fire resistance of the connections without requiring them to be stronger.

► Experimental investigation of the robustness of connections to CFT columns in fire. ► Reverse-channel connections facilitate site-bolted connections to hollow section columns. ► Reverse-channel connections possess excellent ductility, improving frame robustness in fire. ► Ductility can be controlled by varying the connection geometry.