Prefabricated connection for steel beam and concrete-filled steel tube column

A new type of connection system with steel beam and concrete-filled steel tube (CFST) column is proposed in this paper. This type of connection system uses internal stiffeners and high-strength threaded steel rods to connect the steel beams in two directions with the assistance of side plates pre-welded on the column, intending to serve for high-rise buildings where moderate or high ductility is required, and is geometrically possible to be covered within the wall or floor space therefore offering architectural pleasing. The force transfer mechanisms of the connection are important for the corresponding load-carrying capacities and may be different in the two beam directions. In order to investigate the mechanical properties of the connection system, four different specimens, including interior and exterior connections with corresponding columns and beams in two directions, were made and examined under monotonic loadings, further with comparison to FE modelling results. The results of experimental and numerical investigations indicate the proposed connection system offers satisfactory stiffness and load-carrying capacities. Force transfer mechanisms are discussed with assistance from stress and strain responses identified from validated FE modelling in details. Design considerations are further highlighted for implementation in practice. •Proposal of a new prefabricated connection for steel beam and CFST column.•Detailed experimental and modelling results on the proposed new connection.•Understanding of the connection stiffness with different configurations.•Understanding of failure modes and capacities for the connection.•Clarification of force transfer mechanisms in the connection with different details.