Cathodic protection of steel in offshore concrete platforms

Journal Article · Thu May 01 04:00:00 EDT 1980 · Mater. Performance; (United States)

OSTI ID:5472822

Gjorv, O E; Vennesland, O

To improve existing corrosion-control criteria for offshore concrete platforms, researchers studied the effects of various polarization levels on the reinforcement-bar bonding. Experimental investigations indicate that polarization of embedded steel down to -1350 mV (vs a saturated calomel electrode) has no harmful effect on bond strength and may even improve the bond strength of initially clean and smooth steel. For increasing polarization levels, fewer chloride ions from the seawater penetrate the concrete; a calcareous coating on the concrete surface may form at high polarization levels. The current necessary for cathodic protection of embedded steel is controlled primarily by the rate of oxygen diffusion through the concrete. Measurements indicate that the resistance to oxygen diffusion may be 10 times higher through the interface between the concrete and steel than through the concrete cover. The current density necessary for polarizing embedded steel in offshore concrete platforms may be as low as 0.014 mA/ft/sup 2/ (0.15 mA/m/sup 2/).

• Research Organization: Univ. of Trondheim, Norway
• OSTI ID: 5472822
• Journal Information: Mater. Performance; (United States), Journal Name: Mater. Performance; (United States) Vol. 19; ISSN MTPFB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105 -- Metals & Alloys-- Corrosion & Erosion
42 ENGINEERING
420206* -- Engineering-- Mining & Drilling Equipment & Facilities-- (1980-1989)
ALLOYS
BUILDING MATERIALS
CATHODIC PROTECTION
CONCRETES
CORROSION PROTECTION
ELEMENTS
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS
NONMETALS
OFFSHORE PLATFORMS
OXYGEN
STEELS