Post-repair performance of eccentrically loaded RC columns wrapped with CFRP composites

Abstract

This paper presents the results of a research program for examining the post-repair performance of eccentrically loaded corrosion-damaged reinforced concrete (RC) columns wrapped with carbon fiber reinforced polymer (CFRP) composites. The specimens, except a control undamaged group, were initially exposed to accelerated corrosion for 30 days using an impressed current technique. Following the initial corrosion, the damaged specimens were either repaired with full or partial CFRP wrapping systems or kept unrepaired. A group from the damaged specimens were further exposed to 60 days of corrosion exposure. All specimens were tested to failure under various eccentric loading with a nominal eccentricity-to-section height ratio (e/h) in the range of 0.3–0.86. Test results showed that full CFRP wrapping system effectively reduced the post-repair corrosion rate relative to that of the unwrapped specimens whereas partial CFRP wrapping had almost no effect on the steel mass loss. The strengths of the damaged specimens fully wrapped with CFRP were higher than those of the control specimens at the end of the post-repair corrosion phase. The strengths of the damaged partially wrapped specimens were higher than those of the control at nominal e/h values ⩽0.43. At higher e/h values, the strengths of the partially wrapped specimens were lower than those of the control but still higher than those of the damaged unrepaired specimens. An analytical model that accounts for the confinement effect of the CFRP and the change in geometry under eccentric loading was employed to predict the columns’ strength. The model’s predictions were validated against test results.