FRP Application in Underwater Repair of Corroded Piles

Synopsis: The poor durability of conventional corrosion repairs has led to increased interest for its replacement by fiber reinforced polymers (FRP). Over the past decade, several highway agencies completed demonstration projects in which FRP was used to repair corrosion damage on surfaces that were dry. These repairs have held up well and show little sign of deterioration. The availability of resins that can cure in water has made it possible to explore the application of FRP for the underwater repair of corrosion-damaged piles. This paper presents findings from three demonstration projects in which corroding reinforced and prestressed piles at two contrasting locations were repaired using two different FRP systems. Several piles were instrumented to allow long-term corrosion monitoring. The projects confirm the feasibility of conducting underwater FRP repairs in tidal waters. Preliminary data suggests that the wrap leads to a reduction in the prevailing corrosion rate.