Department of Defense piers and wharves, most of which are over 50 years old, are
often supported by reinforced concrete piles. These piles, when exposed to seawater, can
incur severe corrosion of the steel and concrete spalling. This type of damage contributes to
an annual maintenance cost of $99M for the waterfront structures that they support.
Fiber reinforced polymeric composite wrapping systems have been evolving and are
now a viable solution to repair concrete structural piles. These wrap systems, in marine
applications, have not proven to be completely successful since some FRP wrap systems may
contain the concrete but not fully arrest the corrosion. Other systems are limited in their
structural capabilities and abrasion resistance.
This paper describes a hybrid pile repair system that uses a FRP wrap that can be
placed and cured underwater and is integrated with galvanic cathodic protection. The system
will provide corrosion and impact resistance and greatly reduce maintenance costs.
Demonstration of the system on the support piles for two dolphin pier structures in Kawaihae
Harbor, HI is documented. Monitoring of the corrosion potential of the reinforcing steel and the
effectiveness of the wrap in protecting both the concrete and steel will be assessed over the
coming years and reported on.
Keywords: fiber reinforced polymers, corrosion cathodic protection, underwater, repair