Abstract
Research was conducted to determine the effect of electrochemical aging on large-area arc-sprayed Zn anodes for cathodic protection (CP) of bridges and other reinforced concrete structures. The study focused on the influences of total charge passed and concrete surface preparation on bonding of Zn to the concrete. Half the samples were preheated prior to being arc-sprayed with Zn. The preheated samples had initial bond strengths 80% higher than the unheated samples. This difference became insignificant after ≈ 200 kcoul/m2 (5.2 A-h/ft2). Bond strengths for all samples started to decrease after ≈ 600 kcoul/m2 (15.5 A-h/ft2). Changes in bond strength were correlated with observed changes in permeability of the Zn coating to water, electrical behavior of the Zn-concrete interface, charge-transfer resistance, and chemical composition at the Zn- concrete interface.
