Corrosion in concrete

Corrosion of rebar in a concrete involves large sums of money where about $6.4 to $10.7 Billion worth of costs in a repair of "corrosion" on highway bridges in the USA. Four methods that are commonly used to prevent corrosion have been tried where each method had their own advocate and detractors. One such method to mitigate such corrosion is to add inhibitors to the concrete. Another method is the use of current cathodic protection (CP) which can be applied even when the structure is already corroding. The use of coatings can also help prevent corrosion as with the likes of zinc coatings. Furthermore, the development of methods of monitoring may also come in as corrosion prevention.