In the last decade, there has evolved an increasing awareness and understanding of environmental effects and their potential for long term degradation of the structures we build. Today, there is a better understanding of such phenomena as carbonation of concrete and the ingress of chloride ions even in crack-free concrete. As a result of these factors and recent evidence of severe corrosion damage, in many countries an increasing concern has arisen among engineers regarding possible corrosion damage to prestressing tendons and long-term service life. This paper discusses the magnitude of the problem, the corrosion mechanism and various types of corrosion. It also presents examples of corrosion damage and identifies those methodologies that have either been used or could potentially be used to provide increased corrosion protection of prestressing steels.
