Long-term Performance and Versatility of Zinc Sacrificial Anodes for Control of Reinforcement Corrosion, Sergi, Simpson & Potter

Since its development in the mid-nineties, numerous installations of the Fosroc zinc sacrificial anode have been carried out in repairs to steel reinforced concrete structural elements suffering from corrosion. From these, more than a dozen sites have been thoroughly monitored in the UK and worldwide. Results so far have been very encouraging with current densities ranging between 0.8 mA/m2 and 10 mA/m2 of steel surface depending on the type of application which includes cathodic prevention, corrosion control and cathodic protection. These levels of currents were shown to be sufficient to overcome any further visible corrosion of the steel reinforcement extending the service life of the repairs significantly. Some of the early trials have been monitored for nearly ten years now. This presents an opportunity for the results to be analysed and the performance of the sacrificial anodes to be critically assessed medium to long term. This paper reviews the performance of the anodes in terms of current output and steel polarisation levels over the years. The prospects of a further recently developed improved sacrificial anode system achieving substantially improved performance are reviewed and discussed. (read more)