Additive composition for Portland cement materials
AssigneeThe Euclid Chemical Company
InventorValery Tokar
Life of this patent
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Abstract
An additive composition has been formulated which accelerates the setting time, and also improves the compressive strength of Portland type cement, mortars and concretes. The additive composition consists essentially of a concentrated aqueous solution of calcium nitrate and a waste byproduct stream of a mixture of polyethanolamines (referred to as "triethanolamine bottoms") to which solution is added a minor amount of an alkali metal or alkaline earth metal salt of a polyhydroxy aliphatic compound such as gluconic acid, or of lignosulfonic acid.
Claims10
An additive composition to decrease the normal setting time and increase the normal compressive strength of a portland cement containing composition such as mortar and concrete, consisting essentially of, an aqueous solution of (i) calcium nitrate present in an amount of at least 30 parts by weight per 100 parts of said solution, and (ii) a polyalkanolamine of a lower alkanol having from 2 to about 5 carbon atoms, said polyalkanolamine being present in an amount in the range from about 0.05 parts to about 5 parts per 100 parts by weight of said solution, said solution being stable in storage in the temperature range from about 32.degree. F. to about 140.degree. F.
A concrete mix comprising a portland cement and a set-accelerating additive composition consisting essentially of (i) Ca(NO.sub.3).sub.2 in an amount from about 0.5 percent to about 3 percent by weight of said cement as an aqueous solution free of CaCl.sub.2 to which solution is added (ii) diethanolamine, triethanolamine, or a mixture of polyethanolamines, in an amount in the range from about 0.005% to about 0.3% by wt of said cement, and optionally, (iii) an alkali metal salt or an alkaline earth metal salt of an organic stabilizer selected from the group consisting of an aliphatic polyhydroxy cpmpound having from about 5 to about 9 carbon atoms and lignosulfonic acid, in an amount in the range from about 0.005% to about 0.1% by wt of said cement, whereby the concrete formed will develop a compressive strength of at least about 2500 psi at the end of 3 days.
A process for reducing the setting time of a concrete mixture made with a portland cement composition and for increasing the compressive strength of a set concrete mixture at the end of a predetermined period of time, which process comprises adding to the cement composition an effective amount of an aqueous additive composition consisting essentially of, (i) Ca(NO.sub.3).sub.2 in an amount from about 0.5 percent to about 3 percent by weight of said cement as an aqueous solution free of CaCl.sub.2 to which solution is added (ii) diethanolamine, triethanolamine, or a mixture of polyethanolamines, in a combined amount in the range from about 0.005% to about 0.3% by wt of said cement, and, optionally, (iii) an alkali metal salt or an alkaline earth metal salt of an organic stabilizer selected from the group consisting of an aliphatic polyhydroxy compound having from about 5 to about 9 carbon atoms and lignosulfonic acid, in an amount in the range from about 0.005% to about 0.1% by wt of said cement, whereby the concrete formed will develop a compressive strength of at least about 2500 psi at the end of 3 days.
Dependencies are inferred from the claim text.