Fiber-Reinforced Polymer Pile Repair Incorporating Cathodic Protection

Fiber-reinforced polymers (FRPs) are increasingly being used for corrosion repair. As barrier elements, FRPs can only slow down corrosion. Cathodic protection (CP) is the only proven method for stopping electrochemical corrosion of steel. But a new method repairs corrosion damage: a sacrificial CP system is incorporated within an FRP repair. The system was implemented in a demonstration project in which corroding piles supporting the Friendship Trail Bridge, Tampa Bay, Florida, were repaired. The repaired piles were instrumented so that performance of the CP system could be assessed. Results indicate that the CP system is effective in protecting the reinforcing steel. It also shows that corrosion rates are lower in FRP-wrapped piles. This lower rate can increase the life of anodes used by the CP system by more than 20%.