Patent ID: 6764615
Filing Date: 2004-07-20
Classification: C04B

Abstract:
The method of providing multiple sources of a migratory corrosion inhibitor to metallic reinforcements embedded in concrete through additions of said corrosion inhibitors to raw hydrated concrete mix, with said method comprising the steps of adding first and second sources of migratory corrosion inhibitors to the raw hydrated concrete mix prior to the mix being introduced into a form defining a structural member and wherein:(a) said first source consists of a powdered migratory corrosion inhibitor selected from the group consisting of sodium sebacate and potassium sebacate, dicyclohexylammonium nitrite, sodium nitrite, zinc gluconate, sodium gluconate, and calcium nitrite; (b) said second source consisting of an in situ coextruded blend of a selected migratory corrosion inhibitor in a polymeric resin matrix wherein said in situ corrosion inhibitor is selected from the combination of: (i) an alkali metal salt or alkaline earth metal salt of a dibasic acid containing from 8 to 12 carbon atoms together with (ii) one or more migratory corrosion inhibitor selected from the group consisting of an alkali metal gluconates, zinc gluconate, and cyclohexylammonium benzoate, with the alkali metal or alkaline earth metal in said inhibitors being sodium, potassium, or calcium; and (c) wherein the total amount of corrosion inhibitor present in the raw concrete is between about 16 ounces and 24 ounces per cubic yard of raw concrete mix, with the powdered corrosion inhibitor comprising between 70% and 80% by weight of the total corrosion inhibitor, balance in situ coextruded corrosion inhibitor.