Anodes for cathodic protection of reinforced concrete
- Albany Research Center
Consumable anodes were evaluated in the laboratory for use in cathodic protection systems for steel reinforced concrete bridges in coastal environments and in areas where de-icing salts are employed. The anode materials include Zn-hydrogel and thermal-sprayed Zn, Zn-15Al, and Al-12Zn-0.2In. These anodes were evaluated for service in both galvanic (GCP) and impressed current (ICCP) cathodic protection systems. ICCP anodes were electrochemically aged at a factor of 15 times greater than used by the Oregon Department of Transportation in typical coastal ICCP systems (2.2 mA/m{sup 2} based on anode area). Increasing moisture at the anode-concrete interface reduced the operating voltage of all the anodes. The pH at the anode-concrete interface fell to 7 to 8.5 with electrochemical age. Bond strength between the anodes and concrete decreased with electrochemical aging. Interfacial chemistry was the critical link between long-term anode performance and electrochemical age. Zn-hydrogel and the rmal-sprayed Zn and Al-12Zn-0.2In GCP anodes appear to supply adequate protection current to rebar in the Cape Perpetua Viaduct.
- Research Organization:
- Albany Research Center, Albany, OR (US) (US)
- Sponsoring Organization:
- Oregon Department of Transportation (ODOT) (US) (US)
- OSTI ID:
- 759919
- Report Number(s):
- DOE/ARC-2000-002; MOA 14-09-0070-1595; Corrosion 2000 paper no. 810
- Country of Publication:
- United States
- Language:
- English
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