CHALLENGES IN EVALUATING DIFFERENT REINFORCEMENT MATERIALS

摘要

Techniques to minimize the corrosion of steel in concrete have involved making the concrete less permeable by coating the concrete or adding admixtures to the concrete; changing the environment that the steel resides in by electrochemical means; and changing the reinforcement material. The latter strategy has been implemented by coating the steel or choosing inherently more corrosion resistant materials than steel. This paper describes an investigation in which the corrosion behavior of a number of materials is being compared with that of black steel. The materials being tested are two epoxy coated bars (made with bendable epoxy coatings), an epoxy coated bar (made with a nonbendable epoxy coating), galvanized steel (galvanized before or after bending), nylon coated steel, polyvinyl chloride coated steel, stainless steel clad steel, and stainless steel. The alternative materials are being tested using a procedure similar to ASTM G 109, a test in which current is measured between steel in chloride-free and chloride-contaminated concrete. Although this technique was initially used to evaluate different corrosion inhibitors, modified versions have become popular techniques for evaluating different materials as well. This paper describes some of the challenges associated with using it to compare the corrosion behavior of a number of different materials.