Seismic Response of Exterior RC Column-to-Steel Beam Connections

Abstract

The inelastic cyclic response of hybrid connections consisting of RC columns and steel beams (RCS) is studied in this paper. Experimental results from the lateral load testing of nine exterior RCS connections are presented. The primary joint details investigated are two-part U-shaped stirrups passing through holes in the web of the steel beams, steel band plates or cover plates surrounding the joint region, steel fiber concrete or engineered cementitious composite material in the connection, and bearing bars attached to the steel beam. Experimental results indicate that RCS frames are suitable for use in high seismic risk zones. All of the specimens maintained their strength at large levels of story drift without significant loss of stiffness. A joint hoop volumetric ratio of 0.9% was found to be adequate for confinement in RCS joints. However, the amount of joint stirrups can be reduced or even eliminated if steel band plates, engineered cementitious composite material, or fiber reinforced concrete are used in the joint.