Seismic behavior of corrosion-damaged reinforced concrete columns strengthened using combined carbon fiber-reinforced polymer and steel jacket

Summary sults of a research program aimed at investigating the effectiveness of simultaneous application of carbon fiber-reinforced polymer (CFRP) sheets and steel jacket to upgrade corrosion-damaged reinforced concrete (RC) columns was presented. A total of 14 RC columns were tested under combined lateral cyclic displacement excursions and constant axial load. The variables studied in this program included effectiveness of different strengthening techniques, as well as effects of degree of rebar corrosion, axial load, CFRP sheets and steel jacket. It was showed that strengthening corroded RC columns with combined CFRP sheets and steel jacket was effective in enhancing the seismic performance of the columns and resulted in more stable hysteresis curves with lower strength degradations as compared with the un-strengthened ones. Additionally, it was also found that the corroded RC columns strengthened with combined CFRP sheets and steel jacket behaved better than those strengthened only with the single material. Analytical study was conducted and compared with the experimental results. A good agreement was observed.