Patent US4286991A successfully refreshed from Google Patents.
US4286991A
Expired / Lapsed
US
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Very high early strength cement
Assignee: United States Gypsum Co
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Filing: 1980-04-25
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Granted: 1981-09-01
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Expires: 2000-04-25
Abstract
Abstract A combination of a hydroxy polycarboxylic acid and a starch hydrolyzate improves the compressive strength at early and late ages of a calcium sulfoaluminate cement.
Inventors
- 👤 Richard E. Galer
- 👤 Paul C. Webb
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 02:28
CPC Classifications
C; C04; C04B; C04B28/00; C04B28/02; C04B28/06; C04B28/065
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
86 words
A hydraulic cement composition comprising from about 3.75% to about 40% of the compound 3CaO,3Al 2 O 3 .CaSO 4 , from about 0.1% to about 5% of lime and from about 3% to about 35% of calcium sulfate, dicalcium silicate, from about 0.1% to about 2% hydroxy polycarboxylic acid, and from about 0.25% to about 4% of starch hydrolyzate solids from a hydrolyzate having a dextrose equivalent of from about 1 to 100, said amounts being based upon the total dry weight of said composition.
Claim 2
Dependent Claim
86 words
A hydraulic cement composition comprising from about 3.75% to about 40% of the compound 3CaO,3Al 2 O 3 .CaSO 4 , from about 0.1% to about 5% of lime and from about 3% to about 35% of calcium sulfate, dicalcium silicate, from about 0.1% to about 2% hydroxy polycarboxylic acid, and from about 0.25% to about 4% of starch hydrolyzate solids from a hydrolyzate having a dextrose equivalent of from about 1 to 100, said amounts being based upon the total dry weight of said composition.
Claim 3
Dependent Claim
11 words
The composition of claim 1 wherein the acid is citric acid.
Claim 4
Dependent Claim
18 words
The composition of claim 2 wherein the amount of hydrolyzate solids is from about 0.25% to about 2%.
Claim 5
Dependent Claim
32 words
The composition of claim 2 wherein the amount of the citric acid is from about 0.5% to about 2% and the amount of hydrolyzate solids is from about 0.5% to about 2%.
Claim 6
Dependent Claim
23 words
The composition of claim 1 or claim 2 wherein the starch hydrolyzate has a dextrose equivalent of from about 30 to about 70.
Claim 7
Independent Claim
84 words
A method for preparing a cement composition comprising mixing from about 3.75% to about 40% of the ternary compound 3CaO.3Al 2 O 3 .CaSO 4 , from about 0.1% to about 5% of lime, from about 3% to about 35% of calcium sulfate, from about 0.1% to about 2% of a hydroxy polycarboxylic acid, from about 0.25% to about 4% of starch hydrolyzate solids from a hydrolyzate having a dextrose equivalent of from about 1 to 100, and dicalcium silicate as the substantial remainder.
Claim 8
Independent Claim
84 words
A method for preparing a cement composition comprising mixing from about 3.75% to about 40% of the ternary compound 3CaO.3Al 2 O 3 .CaSO 4 , from about 0.1% to about 5% of lime, from about 3% to about 35% of calcium sulfate, from about 0.1% to about 2% of a hydroxy polycarboxylic acid, from about 0.25% to about 4% of starch hydrolyzate solids from a hydrolyzate having a dextrose equivalent of from about 1 to 100, and dicalcium silicate as the substantial remainder.
Claim 9
Dependent Claim
11 words
The method of claim 6 wherein said acid is citric acid.
Claim 10
Independent Claim
117 words
A method for increasing the compressive strength, upon full or partial hydration, of a hydraulic cement comprising from about 4% to about 40% of 3CaO.3Al 2 O 3 .CaSO 4 , from about 0.1 to about 5% of lime, from about 3% to about 35% of calcium sulfate, and dicalcium silicate as the substantial remainder, said method comprising the addition to said cement of a combination of admixtures consisting of from about 0.1 to about 2% of a hydroxy polycarboxylic acid and from about 0.25% to about 2% of starch hydrolyzate solids from a hydrolyzate having a dextrose equivalent of from about 1 to 100, based on the total dry weight of said cement and said admixtures.
Claim 11
Independent Claim
117 words
A method for increasing the compressive strength, upon full or partial hydration, of a hydraulic cement comprising from about 4% to about 40% of 3CaO.3Al 2 O 3 .CaSO 4 , from about 0.1 to about 5% of lime, from about 3% to about 35% of calcium sulfate, and dicalcium silicate as the substantial remainder, said method comprising the addition to said cement of a combination of admixtures consisting of from about 0.1 to about 2% of a hydroxy polycarboxylic acid and from about 0.25% to about 2% of starch hydrolyzate solids from a hydrolyzate having a dextrose equivalent of from about 1 to 100, based on the total dry weight of said cement and said admixtures.
Claim 12
Dependent Claim
44 words
The method of claim 8 wherein the combination of admixtures consists of from about 0.5% to about 2% of the acid and from about 0.5% to about 2% of the hydrolyzate solids, based on the total dry weight of said cement and said admixtures.
Claim 13
Dependent Claim
25 words
The method of claim 8 wherein the acid is citric acid and the hydrolyzate has a dextrose equivalent of from about 30 to about 70.
Claim 14
Dependent Claim
13 words
A mortar comprising the hydraulic cement composition of claim 1 or claim 2.
Claim 15
Dependent Claim
12 words
A concrete prepared from the composition of claim 1 or claim 2.
Claim 16
Dependent Claim
12 words
A grout comprising the cement composition of claim 1 or claim 2.
Claim 17
Dependent Claim
24 words
The method of claim 8 wherein the combination of admixtures consists of about 0.5% of the acid and about 1% of the hydrolyzate solids.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-08-31 | 1985-03-02 | 1985-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-31 | 1989-03-02 | 1989-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-31 | 1993-03-02 | 1993-09-01 | $7700.00 | Window Closed / Lapsed |