Performance-based evaluation of reinforced concrete building exterior joints for seismic excitation

Beam-column joints of nonductile reinforced concrete buildings that were built prior to the current seismic code provisions have been investigated using several performance-based criteria. Four half-scale reinforced concrete exterior joints were tested to investigate their behavior in a shear-critical failure mode. The joints were subjected to quasi-static cyclic loading, and their performance was examined in terms of lateral load capacity, drift ratio, axial load reduction in the column at high drift ratios, joint shear strength, ductility, shear deformation angle of the joint, and residual strength. Two levels of axial compressive column load were investigated to determine how this variable might influence the performance of the joint. Specific performance levels for this type of reinforced concrete joint were established and a comparison was made to current design and rehabilitation standards. A limit states model was established, which could be used for performance evaluation or seismic rehabilitation.