Sacrificial Point Anodes for Cathodic Prevention of Reinforcing Steel in Concrete Repairs—Part 2: Performance Modeling

Abstract

This paper addresses projecting the performance of point anodes for patch repair applications as a function of service parameters and anode aging. Input data from a concurrent experimental test program are presented as well. Modeling of a generic patch configuration was implemented with a one-dimensional approximation. The model calculated the throwing distance that could be achieved by a given number of anodes per unit perimeter of the patch, concrete thickness, concrete resistivity, amount of steel, and amount of polarization needed for cathodic prevention. The model projections and aging information suggest that anode performance in likely application scenarios may seriously degrade after only a few years of operation, even if a relatively optimistic 100 mV corrosion prevention criterion were assumed. The effect of adopting less conservative criteria proposed in the literature is presented as well and the need for supporting information is discussed.