Analytical Evaluation of Galvanic Anode Cathodic Protection Systems for Steel in Concrete

Increasing attention has been focused in recent years upon galvanic anode cathodic protection (CP) for corrosion control of steel in atmospherically exposed concrete. While effectiveness of this type of CP can be assessed by depolarization testing and perhaps other procedures, no method presently exists for analytically characterizing and interrelating the relative influence of various system and corrosion cell parameters. Of particular interest is the electrochemical behavior of the anode since its characteristics often control CP effectiveness. In view of this, a procedure is described in terms of relevant electrochemical parameters that permits 1) cathodic polarization of embedded steel in concrete to be quantitatively characterized and for the role of different system variables affecting this polarization to be identified and 2) projection of galvanic anode performance and of CP system life. Utility of the method is demonstrated using previously reported data for laboratory specimens and a field structure.