The effectiveness of cathodic protection (CP) was investigated by applying it to reinforced concrete specimens that were contaminated by chlorides; the specimens were broken open at intervals so that the reinforcement could be examined directly to assess the extent of any corrosion. This was compared with the condition of similar reinforcement in unprotected control specimens. Cathodic protection significantly reduced both the extent and severity of the corrosion which developed and had no detectable effect on the steel-to-concrete bond strength. It was also demonstrated that a powered CP anode had the added benefit of reducing chloride penetration. CP was under constant voltage control and this led to large variations in the current applied to the specimens. Potential decays also varied considerably and there was a correlation between the decay and applied current.
Samenvatting