This paper discusses the use of carbon fiber-reinforced polymer (CFRP) wraps as a rehabilitation technique for corroded reinforced concrete columns. The effect of applying the wraps at early ages of the columns and its effect on corrosion propagation is addressed. Interaction between corrosion phenomena and the CFRP wrapping is studied through simple combinations of both factors. The laboratory work included testing of 52 reinforced concrete cylinders. Two groups of cylinders were subjected to either an aggressive environment or impressed current (galvanostatic) corrosion. Part of each group was wrapped before the corrosion initiation. The wrapping consisted of one or two layers of CFRP, applied either fully or partially over the cylinder height. Condition of the cylinders was monitored through half-cell potential measurements, linear polarization resistance, and crack mapping. The effect of prewrapping on the corrosion development was analyzed. At the end of the experiment, the cylinders were tested to failure under axial compression. Concrete was analyzed for total chloride content to study the efficiency of the wraps as a barrier for contaminated water. Steel cages were chemically cleaned to calculate the mass lost due to corrosion. It was concluded that applying CFRP wraps significantly decreases corrosion activity when applied over the entire specimen. The application of the wraps before corrosion propagation will prevent corrosion from taking place, while the application of the wraps after corrosion occurrence will drop the rate of corrosion sharply. This effect is probably a virtue of the epoxy saturant used to apply the CFRP sheets and not of the fibers themselves. |
