Experimental investigation of assembly-oriented steel column-beam connection with transverse reverse channels for prefabricated structures

The purpose of this study is to experimentally investigate the mechanical behaviour of the innovative steel column-beam connection involving transverse reverse channels in prefabricated structures with the aim of improving the assemblability during the construction processes. A series of experiments were performed on steel square hollow section (SHS) column and H-section beam connection involving three different transverse reverse channel configurations, i.e., unstiffened transverse reverse channel (UTC), between-channel stiffened (BCS) transverse reverse channel, and in-channel stiffened transverse reverse channel (ICS). The traditional connection involving vertical reverse channel (VRC) was also tested as the control to evaluate the mechanical performance of the new column-beam design, such as flexural resistance, strain distribution and failure modes. The experimental results demonstrate that stiffening the transverse reverse channels internally (ICS) could significantly strengthen the flexural resistance of the connection and the out-of-plane rigidity of the channel web. For example, the flexural resistance of ICS connection is more than 50% and 100% higher than that of the VRC and UTC connection, respectively. However, stiffening between the two transverse reverse channels externally (BCS) has little influence in the flexural resistance of the connection. The failure of the ICS connection is mainly due to the buckling of the beam, while UTC and BCS connections fail because of excessive deformation of the transverse reverse channels. Theoretical formulas can conservatively estimate the bending bearing capacity of those connections.