Use of Cathodic Protection To Combat Corrosion of Bridge Decks

In response to a congressional request, GAO reported on the protection of reinforced concrete bridge decks and the Federal Highway Administration's (FHwA) efforts to promote cathodic protection to combat corrosion of the reinforcing steel in the decks.

According to FHwA, one way of extending the life of corroding reinforced concrete bridge decks is cathodic protection. Therefore, promotion of cathodic protection is a high priority within FHwA, and its advantages are brought to the attention of state highway agencies. In addition, the use of cathodic protection can save billions of dollars. Since 1973, FHwA has spent over $5 million on research and development of bridge protection systems; about $1.5 million of this was spent for studies of cathodic protection. FHwA coordinates research and experimental construction in cathodic protection with states, highway authorities, private firms, and consultants to provide new insights into the corrosion problem and the means of combatting it. In addition, FHwA is developing projects to test cathodic protection on bridge substructures and is planning to conduct a national symposium to promote the technology. For the past 9 years, FHwA has provided educational, technical, and funding assistance to 25 highway agencies for the construction and evaluation of more than 35 cathodic protection installations for demonstration purposes. A new regulation on bridge deck protective systems has eliminated a list of acceptable protective systems for federal-aid participation, and now each state is able to select a protective system based on local conditions and experience. The rule change reflects the fact that cathodic protection is not necessarily the most cost-effective method of bridge deck protection.