Since its development in the mid-nineties, numerous installations of the alkali activated zinc sacrificial
anodes have been carried out in repairs to steel reinforced concrete structural elements suffering from
corrosion. From these, several 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 8 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 field projects have now been monitored for more than ten years. This presents an
opportunity for the results to be analyzed 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 polarization levels
over the years in site field projects concentrating on a field study which has now completed 10 years.
The prospects of further developed and improved sacrificial anode systems achieving improved
performance are reviewed and discussed.