Rehabilitation of reinforced concrete frame connections using corrugated steel jacketing

An experimental investigation was conducted to study the failure mode of existing reinforced concrete beam-column connections designed during the 1970s. The effectiveness of using innovative corrugated steel jackets for enhancing the seismic shear strength and ductility of these types of connections was examined. Four large-scale beam-column connections were tested under cyclic loading. The four connections represent existing frame connection, current code detailed, and two rehabilitated connections. The variables in the test specimens included the amount of joint and column transverse reinforcement and the jacketing of column only or both column and beam. Test results indicated that the shear strength of jacketed joints can be estimated using an approach that is similar to the current design recommendations for beam-column joints. The corrugated jacket was found to be efficient in the rehabilitation of existing structures not meeting current seismic code requirements. A method is proposed for the design of the corrugated steel jacket to enhance the shear strength and ductility of the beam-column joint.