Response of Earthquake-Damaged RC Columns Repaired with CFRP Composites Using Hybrid Simulation

International experience from the effects of past earthquakes on the existing reinforced-concrete (RC) structures with limited-ductility has shown that many behave poorly and some possess very low levels of safety, to the extent that they are at risk of collapse. While the seriously damaged RC frames may be demolished and reconstructed, a large number of earthquake-damaged RC frames can be repaired and operative again. The primary objective of this paper is to evaluate the capability of carbon-fibre reinforced polymer (CFRP) repair on rehabilitating the earthquake-damaged columns to their initial collapse resistance capacity. A state-of-the-art hybrid testing facility, referred to as the Multi-Axis Substructure Testing (MAST) system, was used to simulate complex time-varying six-degrees-of-freedom (6-DOF) boundary effects on the physical specimens using mixed load/deformation modes. Based on the experimental results, a comparative collapse risk assessment of the column before and after repair was conducted, which illustrates the effectiveness of using CFRP-repair to restore and improve the collapse resistance of earthquake-damaged RC structures.