Efficient shear reinforcement for concrete beam-column joints under earthquake loads

Abstract EN

Current ACI and CSA code provisions recommend large amount of shear reinforcement for concrete beam-column joints in the form of closed hoops and cross ties to ensure confinement of the joint core.

The closed hoops, the cross ties, and the bends required for anchoring the beam bars cause significant congestion in the joint.

Double-headed studs are proposed as shear reinforcement in lieu of conventional closed hoops and cross ties.

Five full-scale beam-column joint specimens were tested under cyclic loading.

One specimen was designed without joint shear reinforcement and used as shear-deficient control specimen.

Another specimen was designed according to the Canadian Code provisions and the joint was reinforced with closed hoops and cross ties.

The joints of the remaining three specimens were reinforced with two different arrangements and amounts of double-headed studs.

The use of headed studs proved to be a viable option for reinforcing exterior beam-column joints.

In comparison with the shear deficient joint, the specimens reinforced with headed studs exhibited considerable enhancement in the behavior, in terms of strength, ductility, energy dissipation, and joint contribution to lateral drift.