Seismic Repair of Hybrid RCS Beam-Column Connections

The repair of two hybrid reinforced concrete (RC) column-to-steel (S) beam (RCS) connections severely damaged during earthquake-type displacements is described in this paper. The repair technique consisted primarily of wrapping the column regions just above and below the steel beam with carbon fiber sheets. The repaired specimens were subjected to lateral displacements of up to 5.0% drift. The behavior of the repaired specimens is compared to that of the original specimens in terms of load-versusdisplacement response, lateral stiffness, joint shear distortion, and strains in the joint transverse reinforcement and longitudinal column bars. The carbon fiber sheets effectively confined the joint region, leading to either the same or higher shear strength and stiffness in the subassemblies. In addition, they controlled the growth of diagonal cracks and prevented spalling of concrete in the corners of the joint.