Cathodic Protection Of Reinforcement In Concrete – Overview And Experience Over 30+ Years

Abstract

This paper gives an overview of long term performance up to 30 years in the field of cathodic protection of steel reinforcement in concrete in The Netherlands, focusing on impressed current systems based on activated titanium anodes. Case studies are presented including applications to large numbers of precast elements corroding due to mixed-in chloride with drilled in titanium anodes, parking garages with titanium strips in cementitious overlays and industrial floors with titanium mesh in overlay. Based on observed failures and replacements, analysis of working life of various types of systems and components and end-of-life considerations are given. CP has become a fully accepted method of securing safety and serviceability of buildings and infrastructure that are prone to corrosion. Observations show that with activated titanium based systems, very long service lives can be obtained. The activated titanium itself keeps working well beyond the observed period of 30 years. Some other components have relatively higher failure rates. The repairs that were required in the cases discussed are dominated by failing anode-copper connections and to a minor extent power sources and potential sensors.