Compressive strength and stress transferring mechanism of joint between steel and RC columns for steel moment resisting frames with new column support system

Our previous papers proposed a pin column support system on 1^st story, which consist of the reinforced concrete downside column and the steel topside column to keep column elastic against base shear force issued by the huge seismic force. The joint consists of an anchor bolt, a cover plate on the RC column and a shear plates into RC column. In this paper, the vertical loading tests are performed to clarify the transmission system of axial force for the joints between the reinforced concrete downside column and the steel topside column. Finally, the yielding strength and ultimate strength are estimated by the closed form solution of the experimental results.