The Corrosion Prevention Association (CPA), one of the associations that comprise the Structural Concrete Alliance, has released two new guides to help newcomers to the industry and those with overall responsibility for structures to understand available cathodic protection (CP) systems and how they work.
Technical Note 11: Impressed Current Anodes for the Cathodic Protection of Atmospherically Exposed Reinforced Concrete summarises the anode systems currently commercially available in the UK, detailing the main features of each system including their installation, typical application and performance.
The document explains that impressed current cathodic protection is widely used to provide corrosion control on reinforced concrete structures suffering from reinforcement corrosion. It is also applied to early 20th century steel framed masonry and brick clad buildings and monuments.
Aimed at ensuring that specifiers and asset managers with overall responsibility for structures understand the properties of the various anode systems available, the document categorises the anode systems available into six main types, namely: conductive organic coatings; thermal sprayed zinc; coated titanium expanded mesh/mesh ribbon in a concrete overlay; coated titanium expanded mesh ribbon – mortared into slots chased into the concrete or embedded in new construction; internal conductive ceramic titania or coated titanium (discrete) anodes; and conductive cementitious overlay containing nickel coated carbon fibres.
By detailing the main features of each type of system and explaining how each works, the extent of use and the expected life and cost of each, the document aims to enable asset owners and managers to make an informed choice about the type of system most appropriate for their structure. However, it stresses that anode selection should be made as part of the design process by a suitably qualified Cathodic Protection Engineer, who has Level 3 certification to BS EN 15257 in cathodic protection of steel in concrete or equivalent knowledge, training and experience.
The Association has also produced a useful glossary of terms. Technical Note 28: A is for Anode provides a brief overview of the technical terms used in cathodic protection of steel in concrete. The glossary is intended to help newcomers to cathodic protection to understand the terms which may be used during a project.
Both documents are available for free download from the Corrosion Prevention Association website. To see the full range of available CPA publications and Technical Notes visit: http://www.corrosionprevention.org.uk/publications.php
The Structural Concrete Alliance brings together the Corrosion Prevention Association (CPA), Concrete Repair Association (CRA) and Sprayed Concrete Association (SCA) to provide authoritative guidance on the repair, refurbishment and renovation of concrete; cathodic protection of steel and concrete structures; and sprayed concrete technology and application techniques.
For further information on guidance documents and training available from the Structural Concrete Alliance, and for details of its free regional CPD seminar programme, visit www.structuralconcretealliance.org.uk.
