What are the challenges with cathodic protection for concrete structures?
Cathodic protection (CP) is a well established technology for the long term corrosion protection of structures suffering from chloride contamination problems. In spite of the extensive use of this technology in Australia over the past 30 years, it appears that achieving the optimum design and installation of CP systems is still a challenging task especially for complex applications.
The most critical part of cathodic protection systems is that the bulk of the system will be embedded in concrete once the installation is completed. As a result, every single aspect of the design and installation must be completed correctly the first time.
Underestimation of the current density required to achieve protection, incorrect arrangement or selection of anodes to achieve adequate current distribution and eliminate defects such as grout deterioration, failure to establish 100% steel continuity, incorrect system zoning, failure of anode or steel connections, poor selection of reference electrodes or where to place them, or poor selection of the control system may have a very negative impact on the performance of the CP system, its maintainability and its capacity to protect the structure adequately.
To get it right from the first time, there is no substitute for extensive experience, not only in the design of CP systems but also in all critical aspects of their installation, monitoring and maintenance.
For over 25 years, Remedial Technology’s principal has been involved in the design, installation, commissioning and monitoring of a very large number of cathodic protection systems in Australia and overseas. Among these systems are the Sydney Opera House support structure of the broadwalks, various wharves at the Ports of Brisbane and Port of Melbourne, a large number of bridges for various councils and the NSW and Queensland road authorities and large CP systems in Hong Kong and China. Over the years, we have substantially improved every aspect of the design and installation processes necessary to achieve optimum, cost effective, durable and low maintenance solutions.