Performance of sacrificial anodes to protect the splash zone of concrete piles

This work describes research carried out at the Corrosion Studies Center, Universidad del Zulia, Venezuela, on the use of sacrificial anodes embedded in concrete to provide cathodic protection for reinforced concrete piles exposed to saline environments. Different alloys of aluminum, zinc and magnesium were studied hi the laboratory, determining their efficiency and evaluating their performance in a solution saturated with Ca(OH), and in mortar (Cl- between 0.0 and 0.5%), using electrochemical techniques (potentials, linear and complete polarization). These results determined that the most efficient cathodic protect-ion of the steel reinforcing the concrete was best afforded by the Al/Zn/In alloy The alloy was evaluated at the field level, protecting reinforced concrete, and later applied to prestressed piles of the Rafael Urdaneta Bridge exposed to the brackish waters of Lake Maracaibo. It showed its effectiveness by protecting the steel at potentials on the order of -900 mV versus Cu/CuSO4.