A review of developments in cathodic protection systems for reinforced concrete structures

¹ Mott MacDonald, Materials and Corrosion Technology, Bristol, UK
² Mott MacDonald, Materials and Corrosion Technology, Altrincham, UK

^* Corresponding author: rene.brueckner@mottmac.com

Abstract

Cathodic protection is a corrosion management strategy for deteriorating reinforced concrete structures or it can be used as preventative measure in situations where corrosion may be expected during the service life as a result of the environmental exposure conditions. The technology has advanced over time. There are now a number of different systems that can conveniently be considered in three categories, including impressed current cathodic protection (ICCP), hybrid cathodic protection (HCP), and galvanic cathodic protection (GCP). Asset owners need to choose which option to use possibly without understanding the different sustainability, environmental, health and safety, construction, technical, operational, and monitoring aspects. Generally, it is agreed among corrosion engineers that ICCP is the most powerful and robust solution for corrosion management in structures with widespread deterioration. HCP and GCP can also be viable options, even in the most aggressive environments with future maintenance intervention. The advantages and disadvantages of each system are discussed in detail. This paper also explains why the commonly accepted life expectancy of ICCP systems is 50 to 75 years compared to HCP and GCP, which are typically limited to 15-30 years. The details of the likely maintenance requirements, associated timescales, and whole-life costs for a 100-year design life are analysed with references to sustainability. That includes a discussion about the corrosion management system that presents the lowest embodied carbon option for different environments.