Alternate anode materials for cathodic protection of steel reinforced concrete

Conference · Mon Jan 01 04:00:00 EST 2001

OSTI ID:895221

Russell, James H; Bullard, Sophie J; Covino, Jr, Bernard S; Cramer, Stephen D; Holcomb, Gordon R; Cryer, Curtis B ^[1]

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1. Oregon Dept. of Transportation

Consumable and non-consumable anodes were evaluated in the laboratory for use in cathodic protection (CP) systems for steel reinforced concrete bridges in coastal environments and in areas where deicing salts are employed. The anode materials included Zn-hydrogel and thermal-sprayed Zn, Zn-15Al, Al-12Zn-0.2In, and cobalt-sprayed Ti. These anodes were evaluated for service in both galvanic (GCP) and impressed current (ICCP) cathodic protection systems. Impressed current CP anodes were electrochemically aged at a current density 15 times as great as that used by the Oregon Department of Transportation in typical coastal ICCP systems (2.2 mA/m2 based on anode area). Increasing moisture at the anode-concrete interface reduced the operating voltage of all the anodes. Bond strength between the anodes and concrete decreased with electrochemical aging. The Zn-15Al and Al-12Zn-0.2In anodes provided adequate protection in GCP but their life was too short in the accelerated ICCP tests. Zinc had an adequate life in ICCP tests but was inadequate as a galvanic anode. Zinc-hydrogel performed well in both tests when the hydrogel was kept moist. Titanium was an excellent anode for ICCP, but is not suitable for GCP.

• Research Organization: Albany Research Center (ARC), Albany, OR
• Sponsoring Organization: USDOE
• OSTI ID: 895221
• Report Number(s): DOE/ARC-2001-024
• Country of Publication: Canada
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AGING
ANODES
CATHODIC PROTECTION
CONCRETES
CURRENT DENSITY
MOISTURE
REINFORCED CONCRETE
STEELS
TITANIUM
US DOT
ZINC
anode materials
anodes
corrosion
electrochemical aging
galvanic cathodic protection (GCP)
impressed current cathodic protection (ICCP)
reinforced concrete
thermal spray