ABSTRACT

Electrochemical corrosion protection systems have been used in Australia for many years for the corrosion protection of concrete infrastructure assets in marine environments.

Impressed current cathodic protection (ICCP) can be highly effective for the corrosion protection of reinforced concrete structures, however, some of the potential shortcomings of these systems are their performance in high resistivity concrete, anode installation defects in tidal zones, premature failure of some system components and the requirements for ongoing monitoring.

For galvanic-based anode systems, most of the recent innovations have been associated with backfill materials and the development of systems that incorporate a temporary impressed current phase followed by permanent galvanic protection. While the long-term performance of some of the newly developed systems is still subject to ongoing assessment, the overall performance data from galvanic-based systems indicates that one of the potential shortcomings is the inability of these systems to deliver sufficient corrosion protection over time, especially in highly corrosive environments.

This paper presents guidelines related to the selection process of the corrosion protection system for concrete structures. These guidelines have been developed based on the author's experience with the design, installation, and monitoring of various corrosion protection systems installed in Australia for the protection of marine infrastructure assets.

INTRODUCTION

Impressed current cathodic protection (ICCP) for reinforced concrete structures has been installed on numerous bridges and wharves in Australia over the past 40 years. The exposure conditions at the majority of these bridges and wharves made them more susceptible to chloride-induced corrosion.

The ICCP systems in Australia are designed, installed and monitored in accordance with the global cathodic protection standards such as AMPP Standard SP 0290-2019 [1], International Standard ISO 12696:2022 [2], and Australian Standard AS 2832.5 – 2008 (R2018) [3].

While the standards include general guidelines related to ICCP installation, commissioning, monitoring and protection criteria, various aspects related to the design and installation are not addressed in the standards. The high level of interest in the cathodic protection technology in Australia among cathodic protection consultants, government authorities and assets owners has created the need for specific research work into various aspects related to the design of cathodic protection systems. Some of the recent research work on electrochemical protection applications conducted at the University of New South Wales (NSW) in Sydney, Australia included topics such as "Concrete Resistivity Impact on the Design of Impressed Current Cathodic Protection Systems" [4], "Data Analysis of the Long-Term Residual Effect of Cathodic Protection on Reinforced Concrete Structures" [5], and "Grout Acidification of Ribbon Anode in Impressed Current Cathodic Protection Systems in Concrete" [6].

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