Experimental investigation on the behavior of reinforced concrete columns to steel beams connections

Hybrid structures consisting of reinforced concrete columns and steel beams (RCS) have gained popularity because of reductions in concrete formwork, increased space availability, economics in construction, energy dissipation capacity of the structure and dead load reduction. On the other hand, the current provisions of codes for reinforced concrete columns to steel beams connections have led to some complex details in practice. In this paper, the behavior of RCS connections is examined, experimentally. Five real scale external connections of RCS with circular concrete columns were prepared and tested. The variable parameters in the specimens include the confinement of concrete columns around and inside the connection region and type of concrete. The confinement of concrete columns provided by the spiral reinforcement and CFRP sheets. The purpose of the study is to propose a connection with simple details and desirable behavior. The results show that the proposed connection can transfer the moment from the steel beams to concrete columns, appropriately. Also, the reinforcement in the connection region together with CFRP sheets increase the ductility and energy dissipation of the RCS connection.