The presentation of the chloride threshold level for corrosion of steel in concrete

摘要

It has been argued that presenting the chloride threshold level as a free chloride content or chloride to hydroxyl concentration ratio in the pore solution of concrete is an improvement over the more commonly used total chloride content. In this review the basis for this hypothesis is examined. Contrary to expectations, an analysis of the literature suggests that, on balance, bound chloride presents a corrosion risk, an effect which may be due to its contribution to the reservoir of available chloride at the steel concrete interface.