What is Cathodic Protection (CP)?
Cathodic protection (CP) is a technique that controls corrosion of a metal surface by making it the cathode of an electrochemical cell.
Two types
- Galvanic (sacrificial) systems. A more electrochemically active metal is attached to the metal that it protects.
- Impressed current systems. A source of direct current drives the protective reaction.
Steel in concrete
CP is also used for the steel reinforcement in concrete. The anodes and the reference electrodes are usually embedded in the concrete when it is built. Impressed current is the usual technique for concrete buildings and bridges. The European standard EN 12696:2012 covers cathodic protection of steel in concrete.
Airfield use
We found no mention of cathodic protection in FAA AC 150/5370-10H, FAA AC 150/5340-30J or the EASA Easy Access Rules for Aerodromes. This page therefore makes no claim about where or how an airfield uses it. An inspector who meets a CP system on a project must follow the project specification and the standard that it names.
Frequently Asked Questions
- How does cathodic protection work?
- It makes the metal that you want to protect the cathode of an electrochemical cell. Corrosion happens at the anode of a cell, so the protected metal does not corrode. An external anode takes the place of the corroding areas.
- What are the two types of cathodic protection?
- Galvanic (sacrificial) systems and impressed current systems. A galvanic system attaches a more electrochemically active metal to the metal that it protects. An impressed current system uses a source of direct current to drive the protective reaction.
- Do airfield standards require cathodic protection?
- We found no mention of it. A text search of FAA AC 150/5370-10H, FAA AC 150/5340-30J and the EASA Easy Access Rules for Aerodromes returned no match for the term. Treat any airfield requirement as unconfirmed until you find it in the governing document.
References
- wikipedia-cathodic-protection
- Cathodic protection Wikipedia
- faa-ac-150-5370-10h
- AC 150/5370-10H, Standard Specifications for Construction of Airports FAA
- faa-ac-150-5340-30j
- AC 150/5340-30J, Design and Installation Details for Airport Visual Aids FAA
- easa-ear-aerodromes
- Easy Access Rules for Aerodromes (Regulation (EU) No 139/2014) EASA
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