Cementitious gypsum-containing binders and compositions and materials made therefrom
AssigneeNational Gypsum Company
InventorsElisha Stav, Edward A. Burkard, Ronald S. Finkelstein, Daniel A. Winkowski, Lambert J. Metz, Patrick J. Mudd
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Abstract
Cementitious binders include calcium sulfate beta-hemihydrate, a cement component comprising Portland cement, and either silica fume or rice-husk ash. The silica fume or rice-husk ash component is at least about 92 wt % amorphous silica and has an alumina content of about 0.6 wt % or less.
Claims52
A cementitious binder comprising:
- (a) calcium sulfate hemihydrate;
- (b) a cement component comprising Portland cement;
- and
- (c) a third component comprising silica fume, said silica fume comprising up to about 0.6 wt. % Al.sub.2 O.sub.3, and being at least about 92 wt. % amorphous SiO.sub.2.
A cementitious composition comprising:
- (a) up to about 90 wt. % of a filler component selected from the group consisting of aggregates and fibers;
- and
- (b) about 10 wt. % to 100 wt. % of a binder comprising
- (i) calcium sulfate hemihydrate;
- (ii) a cement component comprising Portland cement;
- and
- (iii) a third component comprising silica fume, said silica fume comprising up to about 0.6 wt. % Al.sub.2 O.sub.3, and being at least about 92 wt. % amorphous SiO.sub.2.
A construction material prepared by combining a cementitious composition with at least a slight stoichiometric excess of water, said cementitious composition comprising:
- (a) up to about 90 wt. % of a filler component selected from the group consisting of aggregates and fibers;
- and
- (b) about 10 wt. % to 100 wt. % of a binder comprising
- (i) calcium sulfate hemihydrate;
- (ii) a cement component comprising Portland cement;
- and
- (iii) a third component comprising silica fume, said silica fume comprising up to about 0.6 wt. % Al.sub.2 O.sub.3, and being at least about 92 wt. % amorphous SiO.sub.2.
A cementitious composition comprising:
- (a) calcium sulfate hemihydrate;
- (b) a cement component comprising Portland cement;
- and
- (c) rice-husk ash comprising up to about 0.6 wt. % Al.sub.2 O.sub.3 and being at least about 92 wt. % amorphous SiO.sub.2.
A fire-proofing spray or fire-stopping material, comprising:
- (a) about 0 wt. % to about 27 wt. % of an aggregate;
- (b) about 1 wt. % to about 16 wt. % vermiculite ore;
- and
- (c) about 99 wt. % to about 54 wt. % of a binder comprising
- (i) about 60 wt. % to about 75 wt. % calcium sulfate hemihydrate;
- (ii) about 20 wt. % to about 31 wt. % of a cement component comprising Portland cement;
- and
- (iii) about 6 wt. % to about 9 wt. % of a third component comprising silica fume, said silica fume comprising up to about 0.6 wt. % Al.sub.2 O.sub.3, and being at least about 92 wt. % amorphous SiO.sub.2 ;
- and
- (d) a stoichiometric excess of water.
A fire-proofing spray or fire-stopping material, comprising:
- (a) about 0 wt. % to about 27 wt. % of an aggregate;
- (b) about 1 wt. % to about 16 wt. % vermiculite ore;
- (c) about 99 wt. % to about 54 wt. % of a binder, wherein the binder comprises about 60 wt. % to about 75 wt. % calcium sulfate hemihydrate, about 21 wt. % to about 33 wt. % of a cement component comprising Portland cement, and about 4 wt. % to about 7 wt. % of a third component comprising silica fume, said silica fume comprising up to about 0.6 wt. % Al.sub.2 O.sub.3, and being at least about 92 wt. % amorphous SiO.sub.2 ;
- and wherein
- the binder is prepared by dry-blending the calcium sulfate hemihydrate and the cement component, followed by mixing with a stoichiometric excess of water into which the third component has been pre-dispersed, and wherein the ratio of the third component to the cement component is about 0.2/1.0.
A cementitious product made by a process comprising the steps of:
- (a) providing calcium sulfate hemihydrate;
- (b) providing a Portland cement;
- (c) providing a silica fume, said silica fume being a byproduct obtained from the production of silicon or ferro-silicon metals, and comprising up to about 0.6 wt. % Al.sub.2 O.sub.3 and being at least about 92 wt. % amorphous SiO.sub.2 ;
- (d) blending said calcium sulfate hemihydrate, cement, silica fume with water to form a composition;
- (e) forming the composition into a shape;
- and
- (f) curing the shaped composition.
Dependencies are inferred from the claim text.