Experimental Seismic Performance of Beam-Column Subassemblies Using Ductile Embeds

AbstractWhen designed according to current special moment frame requirements, conventional RC beam-column joints in frame-braced buildings subject to design level seismic loads suffer severe damage. Construction of these conventional beam-column joints is also costly and labor intensive. In this paper, the full-scale experimental behavior of two alternative frame-braced subassemblies incorporating ductile embeds is summarized. Observations from the experiments indicate that both specimens exhibit stable hysteretic behavior with no strength degradation in excess of 7% drift ratio. At design plastic rotations expected of conventional beam-column joints, no joint spalling and only minor damage along beam members was observed. A design-oriented lumped element model is described, which reasonably captures the local behavior of the specimens.