State-of-the-art review of cathodic protection for reinforced concrete structures

Cathodic protection (CP) limits the corrosion of a metal surface by making it the cathode of an electrochemical cell. This can be achieved either by using a more active sacrificial anode to create a driving current, or by using inert anodes and impressing a current onto the cathode surface using an external direct current (DC) source. Impressed current cathodic protection (ICCP) is preferred where widespread protection is required, particularly in reinforced concrete structures. ICCP needs a constant DC power supply that is usually provided through a grid connection or independent generators. This paper presents the currently available CP systems for reinforced concrete, particularly ICCP, and the possibility of using self-sufficient and renewable energy systems. The potential for overcoming the mismatch (due to intermittent current) in energy provision from renewable sources with energy needs for CP (constant current) is discussed by exploring methods of storing energy and examining the level of protection provided by intermittent current. Areas that require further research to optimise the design of such systems are highlighted.