Reclamation Information Sharing Environment (RISE)

Determining the remaining service life of coatings on Reclamation structures improves maintenance timing and lowers overall costs. Traditional visual condition assessments quantify coating areas with visible damage but do not evaluate the coating performance. Electrochemical impedance spectroscopy (EIS) measures the coating performance where there is no visible coating damage. This research applied field demonstrations and laboratory experiments to expand on previous work and advance the validity and usefulness of field EIS testing. The research concluded that the distance between test cells has no effect on the results, reported accuracy and impedance upper limits for field potentiostats, drafted an approach for extrapolating long-term laboratory EIS data to aid estimate remaining service life for EIS data from coated structures, and contributed to a draft ASTM International test method. Field demonstration occurred at Green Mountain Powerplant, Salt River Siphon, Agua Fria River Siphon, and Fontana Dam.