Experimental analysis of corroded RC continuous beams rehabilitated by ICCP-SS under unsymmetrical loading

In this study, a total of 14 corroded reinforced concrete (RC) continuous beams rehabilitated by a dual function system—Impressed Current Cathodic Protection-Structural Strengthening (ICCP-SS) with carbon-fabric reinforced cementitious matrix (C-FRCM), were tested under in-plane bending (resulted from unsymmetrical loading) to investigate the influences of corrosion rate, layer of carbon fabric mesh, complete wrapping as the end anchorage and loading scheme. The flexural behaviour including failure modes, load-carrying capacities, load-deflection curves and ductilities of the specimens were carefully studied. The design flexural strengths were calculated based on the current design guidelines, which were compared with the experimental results. It's shown from the experimental data of five-point bending tests that beams strengthened with C-FRCM had higher yielding loads and ultimate loads than corroded beams without rehabilitation. However, the ductility of RC continuous beams was weakened by the C-FRCM strengthening method and its anodic polarization process, in particular for the specimens with more layers of carbon fabric meshes in prefabricated C-FRCM plates and complete wrapping as the end anchorage. Under unsymmetrical loading scheme, the delamination failure of concrete cover was observed and the application of complete wrappings was found to improve the ductility of the specimen. Comparison of the measured and predicted moment capacities showed that the current design guidelines generally underestimate the moment capacities of C-FRCM strengthened RC continuous beams, especially the specimens further strengthened by complete wrapping.