First Year Performance Monitoring Kawaihae Harbor Composite Pile Wrap System with Galvanic Cathodic Protection

An FRP composite pile wrap system integrated with galvanic cathodic protection (CP) was applied to a selective number of pilings supporting two dolphin piers at Kawaihae Harbor, Hawaii.  The technology demonstration was funded under the DoD Corrosion Prevention and Control program.  The FRP wrap, which was applied underwater, provides the reinforced concrete piles with protection from impact and abrasion damage within the splash zone.  The galvanic CP anode system designed to protect the reinforcing steel uses  zinc expanded mesh anode strips within the wrapped sections, supplemented with a zinc bulk anode to protect the submerged portion of the piles.

Performance monitoring of the CP system is carried out by the use of permanently installed Ag/AgCl reference electrodes which monitor and data log instant off potentials. Three reference electrodes are installed on four wrapped piles and three control piles (total of seven piles per pier).  The dolphins have no electrical power and the local monitoring station is powered by the use of solar power, which links to a landside supervisory control and data acquisition (SCADA) system via 900MHz radios.  The SCADA system polls the local monitoring stations every 5 minutes to check communications and records data every six hours for future reference and analysis.

This paper will discuss the overall performance of the system throughout the first year of operation and look in detail at the benefit of taking regular readings when monitoring a tidal application of cathodic protection.