Patent ID: 6358397
Filing Date: 2002-03-19
Classification: C23F,G01N

Abstract:
A method of constructing a concrete structure reinforced with steel rebars, comprising,embedding said rebars in concrete having a pH in the range from above 9 to about 13, said rebars having a coating of essentially pure aluminum in the range from about 0.25 mm to 2 mm thick upon which coating is an oxide layer in the range from 0.1 &mgr;m to 100 &mgr;m thick, said oxide layer comprising aluminum oxide and/or hydrated aluminum oxide in a combined aluminum oxide layer which is in direct contact with said concrete; embedding a corrosion potential sensing member of essentially pure aluminum within said structure; continuously measuring the corrosion potential at the surface of said corrosion potential sensing member relative to a reference electrode until the value stabilizes at a measured stable potential without measuring the corrosion potential at said rebars; anodically connecting said source of potential to an anode proximately disposed relative to said rebars; cathodically connecting said rebars to a source of potential which is sufficiently electronegative with respect to said measured stable potential to repress the cathodic potential of said rebars to within a predetermined range correlatable with a corrosion potential measured at said corrosion potential sensing member; and, continuously maintaining current from said source of electronegative potential at a potential in the range from about 150 mV to less than 300 mV lower than the corrosion potential of said corrosion potential sensing member.