Response of Protective Current to Environmental Conditions During Sacrificial Anode Concrete Repair Treatments

Abstract This work examines the current response of installed “hybrid” (combined impressed current and sacrificial) anodes to changes in environmental conditions and investigates the effect of this “responsive behavior” on anode life span. The behavior reported is also discussed in terms of its correlation with the two reported models regarding the criteria for steel protection in concrete. The study showed that current passed by the installed anode was responsive to changes in concrete temperature, moisture, and chloride content during both the impressed current and galvanic phases of the hybrid treatment. This meant that anode life was conserved in benign conditions and shortened when the concrete environment was aggressive. It was also seen that a high current density impressed current treatment “activated” the installed anode, allowing it to pass a much higher current during the galvanic phase of the treatment. The data collected fits better with the acidification/pit realkalization model for corrosio...