In the past 50 years, U.S. Department of Transportation’s Federal Highway Administration (Washington DC & Florida) have done research on the bridges and offshore platforms that have aggressive chloride environments and show evidence of corrosion after short service periods. They found that, since mid of 1970’s, the cost of repairing or replacing of deteriorated structures has become a major liability for highway agencies. $20 Billion was spent on repairing corrosion problems in the past 10 years and it is increasing at $500 Million per year. The primary cause of this deterioration (cracking, delamination, and spalling) are due to the chloride attacking the reinforced steel.
Various Cathodic Protection techniques were developed to prevent corrosion in their bridges & offshore platforms. The U.S. Department of Transportation’s Federal Highway Administration (Publication no. 00-081, August 2000) is applying cathodic protection on their major bridges/tunnels, etc. The advantage of deploying Cathodic Protection System are:
1. 100% guaranteed service life (10 to 100 years life span)
2. Easy installation
3. Low maintenance
4. Decreases (stop) the risk of corrosion in the reinforced concrete structures
In recent years, Road and Transportation Authority (RTA) of Dubai, have taken the approach of deploying Cathodic Protection System on their assets such as Dubai Water Canal and Shindagha Tunnel since it is a simpler option that allows to decrease the risk of corrosion on their reinforced concrete assets.