Several key issues in the research of connections to concrete filled steel tubular columns

Calculating method and construction details are being critical issues for designing connections to concrete filled steel tubes (CFST). This paper presents a state of the art review in research on the behavior of CFST columns to steel beam and reinforced concrete beam connections. The connection types and their characters are summarized, based on the past researches and experiences. This paper identifies a number of key issues for future research, including mechanics model, simplified design method, the determination of bond strength between the steel tube and the concrete core, the fire and post-fire performance of connections.