Strengthening of reinforced high-strength concrete beam–column joints using advanced reinforcement details

Abstract

Lack of ductility in high-strength concrete members raises serious concerns for overall structural safety, especially for reinforced concrete beam–column joints. In the current study, experimental research was performed to improve the seismic strength and performance of reinforced high-strength concrete exterior beam–column joints under cyclic load reversals. A new design approach for beam–column joints was introduced using advanced reinforcement details. Specimens of reinforced high-strength concrete beam–column joints were manufactured based on the new design method developed from the concept of a moving beam plastic hinge using anchor-type intermediate bars and advanced details of doubly confined closed stirrups in the beam near the joint, and tested for comparison with specimens designed using the conventional approach. The newly developed design approach minimised damage and considerably improved the structural performance of beam–column joints under cyclic load reversals. The manufactured joints were expected to be effective in improving the weakness induced by the brittleness of high-strength concrete in reinforced high-strength concrete beam–column joints.