Plate-strengthened deep reinforced concrete coupling beams

Abstract

Many old reinforced concrete buildings in developed countries need to be strengthened due to the aging of construction materials, changes in functional use or new design loading requirements. In the present study, a series of experiments were conducted attempting to retrofit deep reinforced concrete coupling beams using a bolted steel plate. In addition to the control specimen, the other specimens were bolted with a steel plate on the side face to improve the shear strength and inelastic behaviour. A mechanical device was added to two specimens to restrain plate buckling. The study revealed that adding an external plate is an effective way to improve the shear capacity, energy dissipation and rotation deformability of deep reinforced concrete coupling beams. Moreover, the plate buckling-restrained specimen with a sufficient number of bolts in the anchor regions had a more stable response and better inelastic performance under reversed cyclic loads. These findings can help designers to a better understanding of this type of composite coupling beam.