Abstract: Additive for cementitious compositions, comprising: at least one admixture, such a shrinkage reducing admixture, an air entraining admixture, a water reducing admixture, an inorganic salt, a corrosion inhibitor, an accelerator, a retarder, or mixture thereof; and a triblock polyoxyalkene copolymer surfactant having the formula R1O—(A1O)x—(A2O)y—(A1O)x—R2 wherein R1 and R2 individually represent hydrogen, a C1-C7 alkyl group, a C5-C6 cycloalkyl group, or an aryl group; A1 represents a C2 alkyl group, A2 represents a branched or linear C3 alkyl group; “x” represents an integer of 42-133; and “y” represents an integer of 21 to 68.

Abstract: Mixed anodic/cathodic corrosion inhibitors for use in hydraulic cement, comprising a) a first component consisting of an amount of alkali or alkaline earth metal nitrite sufficient to inhibit anodic corrosion; and b) a second component comprising an agent that acts to increases the anodic corrosion performance of the first component; wherein said first and second components are present in a weight ratio of from about 1:0.1 to 1:1. Optionally an EO/PO superplasticizer can be incorporated where the weight ratio of the first component, i.e., nitrite, to EO/PO superplasticizer is from about 1:0.005 to 1:0.25, with the surprising benefit of increased protection against cathodic corrosion without harming the level of anodic corrosion inhibition.

Abstract: An admixture for cement compositions is provided which contributes both anodic and cathodic corrosion inhibition, and the cement compositions containing such additives. The cement additive is a combination of an anodic corrosion inhibitor such as calcium nitrite, and a cathodic corrosion inhibitor such as calcium stearate or other fatty acid. The mixed inhibitors in accordance with the invention provide as good or better corrosion inhibition than does calcium nitrite when used alone.