Half-cell potential method to investigate corrosion status in reinforced concrete structures

Steel bar corrosion is a critical problem to the durability of reinforced concrete structures, and it is a key factor for safety identification of the concrete structures. Because of the complexity of the corrosion process, it is difficult to detect exactly rebar corrosion in the concrete. There are a variety of methods to make an assessment of the corrosion status, among which some methods are destructive to the concrete structures and undesirable. The nondestructive techniques are very significant and are proposed subsequently. In these nondestructive techniques, the half-cell potential method is commonly used, and it can draw equipotential contour map, by which the engineers can have an intuitional impression of the corrosion conditions. In this paper, the half-cell potential method is introduced, including its principle, the data interpretation, and the factors that influence the half-cell potential readings.