Australia’s novel approach to chloride extraction

Marine & Civil Maintenance Pty. Ltd. (Australia)

^* Corresponding author: nickc@marineandcivil.com.au

Abstract

A driving factor of concrete marine structure service life in Australia is the presence and ingress of chlorides into concrete cover which can ultimately initiate corrosion of the steel reinforcement. Electrochemical Chloride Extraction (ECE), once a dormant technology in Australia has recently re-emerged due to a novel application technique which is providing asset owners a sustainable alternative to other corrosion protection strategies. The ECE process mitigates chloride-induced corrosion of steel reinforcement by extracting chlorides. It also alters the material properties in the concrete cover and at the steel surface, including an increase in near-surface depth concrete resistivity, a measurable increase to the pH around the steel reinforcement, and the re-formation of the protective passive layer on the steel. This paper documents the history of ECE system’s in Australia, discusses variables that may influence efficiency of the process, and analyses results achieved using various system configurations.