Evaluation of corrosion resistance of fusion-bonded expoxy coated rebars in concrete by DC and AC techniques

The corrosion behavior of fusion-bonded epoxy coated steel reinforcements (FBECR), with and without artificial damage, embedded in concrete and immersed in sodium chloride solution has been determined. Four degrees of damage namely 1%, 2%, 3% and 4% were utilized. The corrosion of some of the samples was accelerated by shifting the corrosion potential of the reinforcing steel into the anodic region. Using electrochemical corrosion measurement techniques, the corrosion behavior of FBECRs embedded in concrete was determined. Results obtained from the study indicate that the area of pre-existing damage in the coating of the steel bars correlates well with the corrosion behavior of samples subjected to accelerated corrosion. Samples with 4% damage showed the highest susceptibility to accelerated corrosion followed by 3%, 2% and 1% damage samples. Also, the coating that was applied manually to the ends of the steel bars showed very poor performance. Samples with and without damage tested at the free corrosion potential were not affected by corrosion over the short testing period of the experiment.