Performance-Based Shear Design of Exterior Beam-Column Joints with Standard Hooked Bars

Under earthquake load, the joint shear strength of exterior beam-column joints without adequate ductility details is significantly degraded as the lateral deformation of the moment frame increases. In the present study design equations of the joint shear strength and hoop requirement were developed for the performance-based design of exterior beam-column joints. To estimate the requirements of joint shear strength and hoop strength, the effects of the target drift ratio of the overall moment frame and the bar bond parameters on the joint shear strength were considered. To verify the validity, the proposed design method was applied to existing exterior beam-column joint specimens with or without joint hoops. The predictions of the proposed method were compared to the lateral load-drift ratio relationships of test specimens. Further; on the basis of the results of a parametric study, the proposed method was simplified, and a modification of the current ACI 318 method was proposed for application to performance-based design.