Galvanic corrosion of carbon and steel in aggressive environments

The demand for the use of carbon-fiber-reinforced plastics (CFRP) in rehabi litation of deteriorating infrastructure is increasing worldwide. The desig n characteristics of reinforced concrete or steel members can be enhanced s ignificantly by epoxy bonding CFRP laminates to the critically stressed ten sion areas. There is, however, a concern regarding possible galvanic corros ion when carbon and steel are bonded together. This paper presents the resu lt of a study on the galvanic corrosion between CFRP laminates and steel. A total of 38 specimens made of steel and carbon fibers were prepared and te sted. Two simulated aggressive environments and three different amounts of epoxy coating were used in addition to samples with no coating at all. Furt hermore, the effect of the sizing agent on the galvanic corrosion rate was investigated, and three different solvents were used to remove the sizing a gents from the surface of the carbon fibers. Potentiodynamic polarization a nd galvanic corrosion tests were conducted. The results of the experiments showed the existence of galvanic corrosion; however, the rate of such corro sion could be decreased significantly by epoxy coating.