New developments for corrosion protection of concrete structures in Australia

Abstract

The corrosion protection, repair and maintenance of reinforced concrete structures located along the coast of Australia has been a challenging task for engineers and asset owners over the past thirty years. Most of these structures are bridges and wharves which are situated in marine environments and are subject to tidal exposure. These environmental conditions create challenges in planning repair work, especially if electrochemical systems such as cathodic protection are installed for corrosion protection of these assets. While impressed current cathodic protection (ICCP) is a proven technology which can provide long-term corrosion prevention solutions for marine structures, this technology has been viewed by many asset owners as overly complex and expensive. There is the perception that ICCP systems require costly permanent monitoring programs and have high maintenance costs. These perceptions have been supported by the frequent failure of power supply units, and in some cases, widespread defects associated with ICCP systems such as grout acidification in concrete elements situated in tidal zones. The perception about the complexity of ICCP technology has led to the selection of less effective galvanic-based systems for the protection of assets, and systems which require no monitoring and have low maintenance requirements. This paper will present information on the new developments which have emerged from long-term experience and research work related to the simplification in the design, installation and improved monitoring of ICCP systems.