Process of electrochemically re-alkalizing reinforced concrete
AssigneeNorsk Averflate Teknikk A/S (NOT)
InventorsJohn B. Miller, Oystein Vennesland
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Abstract
A process is disclosed for re-alkalizing carbonized reinforced concrete. An electric current is impressed between adjacent areas of concrete, one of which has become carbonized with consequent loss of pH, and the other of which is adequately alkaline in pH. The impressed voltage causes a migration of hydroxyl ions from the higher pH region to the lower pH region, to effect an increase in pH of the carbonized region to a satisfactory level. The region of high pH concrete may be either non-carbonized areas of the original concrete or a temporarily applied layer of an alkaline electrolyte.
Claims8
The method of re-alkalizing a relatively carbonated zone of a concrete structure from an adjacent zone of relatively alkaline medium, wherein the carbonated zone has a pH substantially below 12, which comprises,
- (a) applying between said zones a direct current voltage of at least about six volts to effect a migration of alkaline ions from said relatively alkaline medium to said relatively carbonated zone,
- (b) generally maintaining said voltage until said relatively carbonated zone reaches a pH of about 12, and
- (c) thereafter discontinuing the application of said voltage.
Dependencies are inferred from the claim text.