US3942994A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Early strength cements
Assignee: Associated Portland Cement Manufacturers Ltd
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Filing: 1974-09-23
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Granted: 1976-03-09
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Expires: 1994-09-23
Abstract
Abstract An early strength hydraulic cement comprising: from 15 to 90 per cent by weight based on the cement, of an orthorhombic or tetragonal phase XC 14 A 5 which is NC 14 A 5 as herein defined or the corresponding phase in which the place of the sodium oxide is at least partly taken by at least one other alkali metal oxide; the balance being predominantly calcium silicates.
Inventors
- 👤 Ransom James Murray
- 👤 Arthur William Brown
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:57
CPC Classifications
C; C04; C04B; C04B7/00; C04B7/02; C04B7/06
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
86 words
An early strength hydraulic cement comprising from 15 to 90 percent by weight, based on the cement, of an alkali metal calcium aluminate phase formed in the calcium oxide-alumina-alkali metal oxide systems by the presence of at least one alkali metal oxide in a total amount of alkali metal oxide in excess of the solid solution limit thereof in cubic tricalcium aluminate, at least part of said at least one alkali metal oxide being sodium oxide and the balance of the cement being predominantly calcium silicates.
Claim 2
Dependent Claim
86 words
An early strength hydraulic cement comprising from 15 to 90 percent by weight, based on the cement, of an alkali metal calcium aluminate phase formed in the calcium oxide-alumina-alkali metal oxide systems by the presence of at least one alkali metal oxide in a total amount of alkali metal oxide in excess of the solid solution limit thereof in cubic tricalcium aluminate, at least part of said at least one alkali metal oxide being sodium oxide and the balance of the cement being predominantly calcium silicates.
Claim 3
Dependent Claim
33 words
A cement according to claim 1 wherein said alkali metal calcium aluminate phase is a sodium calcium aluminate phase containing 2 - 10 percent by weight of sodium oxide based on the phase.
Claim 4
Dependent Claim
20 words
A cement according to claim 1 comprising 20 - 80 percent by weight of said alkali metal calcium aluminate phase.
Claim 5
Dependent Claim
20 words
A cement according to claim 1 comprising 30 - 50 percent by weight of said alkali metal calcium aluminate phase.
Claim 6
Dependent Claim
11 words
A cement according to claim 1 in which magnesia is present.
Claim 7
Independent Claim
125 words
A method of preparing an early strength hydraulic cement comprising from 15 to 90 percent by weight, based on the cement, of an alkali metal calcium aluminate phase formed in the calcium oxide-alumina-alkali metal oxide systems by the presence of at least one alkali metal oxide in a total amount of alkali metal oxide in excess of the solid solution limit thereof in cubic tricalcium aluminate, at least part of said at least one alkali metal oxide being sodium oxide and the balance of the cement being predominantly calcium silicates, which method comprises grinding a clinker formed by burning high alumina Portland cement ingredients in the presence of alkali to form in the resultant product the requisite amount of said alkali metal calcium aluminate phase.
Claim 8
Independent Claim
125 words
A method of preparing an early strength hydraulic cement comprising from 15 to 90 percent by weight, based on the cement, of an alkali metal calcium aluminate phase formed in the calcium oxide-alumina-alkali metal oxide systems by the presence of at least one alkali metal oxide in a total amount of alkali metal oxide in excess of the solid solution limit thereof in cubic tricalcium aluminate, at least part of said at least one alkali metal oxide being sodium oxide and the balance of the cement being predominantly calcium silicates, which method comprises grinding a clinker formed by burning high alumina Portland cement ingredients in the presence of alkali to form in the resultant product the requisite amount of said alkali metal calcium aluminate phase.
Claim 9
Independent Claim
108 words
A method of preparing an early strength hydraulic cement comprising from 15 to 90 percent by weight, based on the cement, of an alkali metal calcium aluminate phase formed in the calcium oxide-alumina-alkali metal oxide systems by the presence of at least one alkali metal oxide in a total amount of alkali metal oxide in excess of the solid solution limit thereof in cubic tricalcium aluminate, at least part of said at least one alkali metal oxide being sodium oxide and the balance of the cement being predominantly calcium silicates, which method comprises grinding a clinker containing said alkali metal calcium aluminate phase with a Portland cement clinker.
Claim 10
Independent Claim
108 words
A method of preparing an early strength hydraulic cement comprising from 15 to 90 percent by weight, based on the cement, of an alkali metal calcium aluminate phase formed in the calcium oxide-alumina-alkali metal oxide systems by the presence of at least one alkali metal oxide in a total amount of alkali metal oxide in excess of the solid solution limit thereof in cubic tricalcium aluminate, at least part of said at least one alkali metal oxide being sodium oxide and the balance of the cement being predominantly calcium silicates, which method comprises grinding a clinker containing said alkali metal calcium aluminate phase with a Portland cement clinker.
Claim 11
Independent Claim
106 words
A method of preparing an early strength hydraulic cement comprising from 15 to 90 percent by weight, based on the cement, of an alkali metal calcium aluminate phase formed in the calcium oxide-alumina-alkali metal oxide systems by the presence of at least one alkali metal oxide in a total amount of alkali metal oxide in excess of the solid solution limit thereof in cubic tricalcium aluminate, at least part of said at least one alkali metal oxide being sodium oxide and the balance of the cement being predominantly calcium silicates, which method comprises blending a cement containing said alkali metal calcium aluminate phase with another cement.
Claim 12
Independent Claim
106 words
A method of preparing an early strength hydraulic cement comprising from 15 to 90 percent by weight, based on the cement, of an alkali metal calcium aluminate phase formed in the calcium oxide-alumina-alkali metal oxide systems by the presence of at least one alkali metal oxide in a total amount of alkali metal oxide in excess of the solid solution limit thereof in cubic tricalcium aluminate, at least part of said at least one alkali metal oxide being sodium oxide and the balance of the cement being predominantly calcium silicates, which method comprises blending a cement containing said alkali metal calcium aluminate phase with another cement.
References Cited (Backward Citations)
US3140956A
Cited
US3874885A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-09 | 1979-09-08 | 1980-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-09 | 1983-09-08 | 1984-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-09 | 1987-09-08 | 1988-03-09 | $7700.00 | Window Closed / Lapsed |