CHALLENGES IN EVALUATING DIFFERENT REINFORCEMENT MATERIALS

摘要

Techniques to minimize the corrosion of steel in concrete have involved making the concrete lesspermeable by coating the concrete or adding admixtures to the concrete; changing theenvironment that the steel resides in by electrochemical means; and changing the reinforcementmaterial. The latter strategy has been implemented by coating the steel or choosing inherentlymore corrosion resistant materials than steel. This paper describes an investigation in which thecorrosion behavior of a number of materials is being compared with that of black steel. Thematerials being tested are two epoxy coated bars (made with bendable epoxy coatings), anepoxy coated bar (made with a nonbendable epoxy coating), galvanized steel (galvanizedbefore or after bending), nylon coated steel, polyvinyl chloride coated steel, stainless steel cladsteel, and stainless steel. The alternative materials are being tested using a procedure similar toASTM G 109, a test in which current is measured between steel in chloride-free and chloridecontaminatedconcrete. Although this technique was initially used to evaluate different corrosioninhibitors, modified versions have become popular techniques for evaluating different materialsas well. This paper describes some of the challenges associated with using it to compare thecorrosion behavior of a number of different materials.