cathodic protection for reinforced concrete structures pdf

The use of steel in concrete has increased massively in the last century, and it is now one of the most commonly used building materials on earth (second to water in usage by mankind). The biggest
durability problem with structures of this material is corrosion of the steel reinforcement. The cause of this corrosion that is most difficult to remedy is the presence of chloride in the concrete,  which allows the steel to corrode at a rapid rate.

Because of the huge economic significance of this problem over the last 50 years, there has been almost continuous research in many countries to categorise the problem. There have been significant attempts to improve the actual life of a reinforced concrete structure by changing the material properties of both the reinforcement and concrete.

Secondly, there have been changes to cover depths of the concrete. Relatively recently, certain countries, such as Saudi Arabia, have been installing cathodic prevention on a large scale to prevent corrosion from initiating by forcing the steel reinforcement to remain as a cathode.

As of yet, there has not been a thorough look at changing the structural design of the steel reinforcement in order to minimise the risk of premature corrosion, although this practice has been
ongoing for many years in the case of steel structures. This design change would be to minimise the formation of anodic sites where preferential corrosion occurs.

The aim of this chapter is not to repeat the accepted wisdom of previous textbooks but to look at the results of recent research and contemplate an alternative view of the corrosion process.