Anodes for cathodic protection of reinforced concrete
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; TRN: AH200033%%206
- Resource Relation:
- Conference: Corrosion 2000, Orlando, FL (US), 03/2000; Other Information: PBD: 1 Mar 2000
- Country of Publication:
- United States
- Language:
- English
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