Study on structural performance of repaired reinforced concrete beams with partially debonded longitudinal rebars

In order to evaluate the structural performance of repaired RC beams with partially debonded longitudinal rebars, structural experiments were conducted. In the experiments, real-scale and half-scale RC beam specimens underwent cyclic loading of 1.0% or less in terms of deformation angle, repaired with epoxy resin injection method, and multiple cyclic loading again. As a result of the experiments, damage was suppressed in specimens with partially debonded longitudinal rebars even after repairs. Further, the specimens with partially debonded longitudinal rebars exhibited high recovery of initial stiffness after repair compared to the specimen with bonded longitudinal rebars. In addition, from study of the costs required to repair cracks, it was confirmed that RC beams with partially debonded longitudinal rebars used smaller quantities of materials used for repairs and could potentially reduce repair cost by approximately 50% compared to RC beams having standard bonding properties.