Thermally-sprayed zinc anodes are used in both galvanic and impressed current cathodic protection systems for reinforced concrete structures. The Albany Research Center, in collaboration with the Oregon Department of Transportation,has been studying the effect of electrochemical aging on the bond strength of zinc anodes for bridge cathodic protection systems. Changes in anode bond strength and other anode properties can be explained by the chemistry of the zinc-concrete interface. The chemistry of the zinc-concrete interface in laboratory electrochemical aging studies is compared with that of several bridges with thermal-sprayed zinc anodes and which have been in service for 5 to 10 years using both galvanic and impressed current cathodic protection systems. The bridges are the Cape Creek Bridge on the Oregon coast and the East Camino Undercrossing near Placerville CA. Also reported are interracial chemistry results for galvanized steel rebar from the 48 year old Longbird Bridge in Bermuda.
KEYWORDS: zinc, themaIspray,anodes, cathodic protection, bridges, galvanize, rebar, concrete, interfacial chemistry.