Electrochemical Performance of Concrete Conductive Anode Paint Used as an Impressed Current Anode Material

Abstract

The impressed current cathodic protection (ICCP) technique is a widely accepted technique to control corrosion of steel in reinforced concrete structures exposed to a high chloride environment. With the growing applicability of the technique, this research focused on developing a new anode material for the system. The author’s previous zinc-rich paint (ZRP) anode is further modified to improve its properties and its performance to be suitable for ICCP. The new concrete conductive anode paint (CAP) was evaluated for various concrete elements with varying steel: concrete ratios. Results showed that concrete CAP possesses excellent electrical conductivity as the anode for the ICCP system irrespective of specimen size. Compared with other available commercial anode paint materials and ZRP anode, concrete CAP is more promising as an ICCP anode material and satisfies the required polarization requirement. Polarization performance showed anode is capable to protect reinforced concrete structure with varied steel: concrete or steel: anode ratio. With an anode current density of 20 mA/m2, the service life was evaluated as 45 years. Cathodic protection is one of the most succesfull and widely accepted technique to control corrosion in chloride contaminated reinforced concrete. However, the commercially available coating anode materials offer the advantage of easy application and good performance compared to other anodes but lacks in its durability and shorter service life. The present manuscript introduces a new paint anode for Impressed Current Cathodic Protection System which offers advantage over currently available anodes in terms of application, performance and durability. Thus, the results of this research can be directly used by contractors, practitioners and highway agencies to make an informed decision on selection of correct anode type for repairing corroded reinforced structures.