A review of cathodic protection systems currently available to combat rebar corrosion caused by chloride ingress in concrete

Throughout the UK and Europe, concrete durability is a subject of considerable concern and study. Many statements have been made with respect to the magnitude of the problem and the probable cost to society. The root cause of the problem has been put down in the majority of cases to steel reinforcement corrosion. Within this context two basic agents can be seen as the initiator of the problem, that of carbonation and chloride contamination of the concrete. Rust stains on the surface of the structure are early signs of a corrosion problem. As the corrosion process continues, iron oxide deposits build up on the affected reinforcement. This increase in volume results in large stresses being developed in the surrounding concrete, leading to cracking and spalling.