Alternative consumable anodes for cathodic protection of reinforced concrete bridges

Conference · Fri Jan 01 04:00:00 EST 1999

OSTI ID:900517

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

---

1. Oregon Dept. of Transportation, Salem, OR

Alternative 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 deicing salts are employed. The anode materials included zinc hydrogel foil and thermal-sprayed Zn, Zn-15Al, and Al-12Zn-0.2In alloys. They were evaluated for service in both impressed current (ICCP) and galvanic (GCP) cathodic protection systems. ICCP anodes were electrochemically aged at current densities of five to fifteen times that used by the Oregon Department of Transportation (Oregon DOT) in typical coastal CP systems (2.2 mA/m2 based on anode area). GCP anodes were electrochemically aged at a rate defined by the steel-anode couple. Both types of anodes were exposed to 80°F, a relative humidity of 85 pct, and were periodically wetted with deionized water. The Zn anode gave the best performance in ICCP systems. The four anodes all produced sufficient current density suitable for use in GCP systems. The anodes materials, ranked in increasing order of GCP current output, were: thermal-sprayed Al-12Zn-0.2In, Zn hydrogel, thermal-sprayed Zn-15Al, and thermal-sprayed Zn.

• Research Organization: Albany Research Center (ARC), Albany, OR
• Sponsoring Organization: USDOE - Office of Fossil Energy (FE); Oregon Dept. of Transportation, Salem, OR
• OSTI ID: 900517
• Report Number(s): DOE/ARC-1999-016
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALLOYS
ANODES
CATHODIC PROTECTION
CURRENT DENSITY
GCP
HUMIDITY
HYDROGELS
ICCP
PERFORMANCE
REINFORCED CONCRETE
STEELS
US DOT
WATER
ZINC
aluminum-12 zinc-0.2 indium
bond strength
bridge
cathodic protection
electrochemical aging
hydrogel
reinforced concrete
thermal spray
zinc
zinc-15 aluminum