Corrosion

Rusty section of a steel railroad bridge.

Corrosion is the deterioration of a material, usually a metal, that results from a chemical reaction with its environment. Formation of an oxide of iron due to oxidation of the iron atoms in solid solution is a well-known example of electrochemical corrosion, commonly known as rusting. Over a period of time the components of a structure may deteriorate to the extent that the structure is no longer sound or safe. Using current corrosion control technology in conjunction with maintenance and monitoring, corrosion other forms of decay may be prevented, extending the lifespan of a structure.

Controlling corrosion in metals

Common strategies for corrosion control in metals include:

1. Designing the structure with corrosion prevention in mind and selecting corrosion-resistant materials when constructing and preserving structures;
2. The application of protective coatings, membranes, and protective sealers to the structure which can serve as a barriers to corrosive environments;
3. The use of direct electrical current and sacrificial materials to mitigate corrosion in reinforced concrete and steel structures, a process known as cathodic protection; and
4. Electrochemical chloride extraction.