US3860433A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Very high early strength cement
Assignee: Individual
•
Filing: 1972-05-30
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Granted: 1975-01-14
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Expires: 1992-05-30
Abstract
Abstract Fast setting hydraulic cement having very high compressive strengths within a few hours of mixing with water, and generally from about 2,900 to over 5,000 p.s.i. within 24 hours, containing beta 2CaO.SiO2; 3CaO.3A12O3CaSO4; and chemically unbound CaSO4 obtained by firing at a temperature between about 1,200 and 1,600*C for about 1 to 5 hours a mixture of a source respectively of CaO, SiO2, Al2O3 and SO3 in proportions of about 1 to 3 moles of CaSO4 to about 0.5 to 2 plus 2n moles of CaCO3 per mole of Al2O3.nSiO2 and grinding the resultant clinker.
Inventors
- 👤 Borje W A Ost
- 👤 Benedict Schiefelbein
- 👤 John M Summerfield
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:39
CPC Classifications
C; C04; C04B; C04B28/00; C04B28/02; C04B28/06; C04B28/065; C04B7/00; C04B7/32; C04B7/323; C04B7/345; C04B7/3453; Y; Y02; Y02P; Y02P40/00; Y02P40/10
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
65 words
A FAST-SETTING HYDRAULIC CEMENT WHICH RAPIDLY DEVELOPES STRENGTH AND WHICH HAS A COMPRESSIVE STRENGTH OF AT LEAST ABOUT 2,900 POUNDS PER SQUARE INCH WITHIN 24 H0URS AFTER INITIATION OF HYDRATION, CONTAINING FROM ABOUT 20 PERCENT TO ABOUT 40 PERCENT BY WEIGHT OF C3A3CS AND FROM ABOUT 10 PERCENT TO ABOUT 35 PERCENT BY WEIGHT OF CHEMICALLY UNBOUND CASO4, AND THE REMAINDER BEING SUBSTANTIALLY BETA C2S.
Claim 2
Dependent Claim
65 words
A FAST-SETTING HYDRAULIC CEMENT WHICH RAPIDLY DEVELOPES STRENGTH AND WHICH HAS A COMPRESSIVE STRENGTH OF AT LEAST ABOUT 2,900 POUNDS PER SQUARE INCH WITHIN 24 H0URS AFTER INITIATION OF HYDRATION, CONTAINING FROM ABOUT 20 PERCENT TO ABOUT 40 PERCENT BY WEIGHT OF C3A3CS AND FROM ABOUT 10 PERCENT TO ABOUT 35 PERCENT BY WEIGHT OF CHEMICALLY UNBOUND CASO4, AND THE REMAINDER BEING SUBSTANTIALLY BETA C2S.
Claim 3
Dependent Claim
32 words
The cement of claim 1 in which the compressive strength is at least 4,000 p.s.i. within 24 hours after initiation of hydration when tested by ASTM C-109 using a 0.49 water/cement ratio.
Claim 4
Dependent Claim
13 words
The cement composition of claim 1 including a small amount of free CaO.
Claim 5
Dependent Claim
17 words
The cement composition of claim 1, being essentially free from C3A and C3S detectable by X-ray diffraction.
Claim 6
Dependent Claim
26 words
The cement composition of claim 1 in which the relative ratio of C3A3CS to CS by X-ray diffraction pattern peaks is about 0.5-2.5 to 1 respectively.
Claim 7
Dependent Claim
45 words
The cement composition of claim 1 which has an X-ray diffraction pattern that shows spacings of about 4.92; 3.76; 3.50; 3.26; 2.92; 2.89; 2.86; 2.80; 2.76; 2.67; 2.66; 2.63; 2.47-2.45; 2.41; 2.35; 2.33; 2.31; 2.30; 2.20; 2.18; 2.06; 2.05; 2.04; 1.990-1.986; 1.872; and 1.745-1.742 A.
Claim 8
Dependent Claim
58 words
The cement composition of claim 1 which has a calculated composition based on wet chemical analysis of about 28% C3A3CS; about 50 percent beta C2S; about 14 percent chemically unbound CS; and minor proportions of free C, the amount of such CS exceeding the amount of such C and their total being about 14 to about 35 percent.
Claim 9
Dependent Claim
45 words
The cement composition of claim 7 and having an X-ray diffraction pattern that shows spacings of about 4.92; 3.76; 3.50; 3.26; 2.92; 2.89; 2.86; 2.80; 2.76; 2.67; 2.66; 2.63; 2.47-2.45; 2.41; 2.35; 2.33; 2.31; 2.30; 2.20; 2.18; 2.06; 2.05; 2.04; 1.990-1.986; 1.872; and 1.745-1.742 A.
Claim 10
Dependent Claim
97 words
A feed mixture for a fast-setting hydraulic cement which rapidly develops strength and which has a compressive strength of at least about 2,900 p.s.i. within 24 hours after initiation of hydration after being fired to a clinker at a temperature between about 1,200* and 1,600*C for about 1 to 5 hours residence time; comprising a mixture of sources respectively of CaO, SiO2, Al2O3 and SO3 in proportions of about 1 to 3 moles of CaSO4 and about (0.5 to 2) + 2n moles of CaO per mole of Al2O3.nSiO2 where n is about 1.5 to about 2.5.
Claim 11
Dependent Claim
97 words
A feed mixture for a fast-setting hydraulic cement which rapidly develops strength and which has a compressive strength of at least about 2,900 p.s.i. within 24 hours after initiation of hydration after being fired to a clinker at a temperature between about 1,200* and 1,600*C for about 1 to 5 hours residence time; comprising a mixture of sources respectively of CaO, SiO2, Al2O3 and SO3 in proportions of about 1 to 3 moles of CaSO4 and about (0.5 to 2) + 2n moles of CaO per mole of Al2O3.nSiO2 where n is about 1.5 to about 2.5.
Claim 12
Dependent Claim
22 words
The feed mixture of claim 9 in which the sources of CaO, SiO2, Al2O3 and SO3 comprise limestone, kaolin clay, and gypsum.
Claim 13
Dependent Claim
30 words
The feed mixture of claim 9 in which the proportions are about 1.75 moles of CaSO4 and about 5.75 moles of CaO per mole of Al2O3.nSiO2 where n is 2.
Claim 14
Dependent Claim
41 words
The feed mixture of claim 9 in which the sources are fired at a temperature of about 1,260*C and the proportions are about 1.6-2.1 moles of CaSO4 and about 5.65-5.95 moles of CaO per mole of Al2O3.nSiO2 where n is 2.
Claim 15
Dependent Claim
74 words
The feed mixture of claim 9 in which the sources are fired at a temperature of about 1,300*C; and the proportions are in the area enclosed by the equations: 0.7X - 2.29Y + 12.0762 0 0.72X + 0.39Y - 3.1728 0; and 1.42X - 1.9Y + 6.9816 0 wherein Y represents the moles of CaO per mole of Al2O3 and X represents the moles of CaSO4 per mole of Al2O3.nSiO2 where n is 2.
Claim 16
Dependent Claim
43 words
The feed mixture of claim 9 in which the sources are fired at a temperature of about 1,350*C; and the proportions are about 1.7-2.8 moles of CaSO4 and about 4.75 to 6.25 moles. of CaO per mole of Al2O3.nSiO2 where n is 2.
Claim 17
Dependent Claim
98 words
A process for preparing a fast-setting hydraulic cement which rapidly develops strength and which has a compressive strength of at least about 2,900 p.s.i. within 24 hours after initiation of hydration comprising: forming a mixture of sources respectively of CaO, SiO2, Al2O3 and SO3 in proportions of about 1-3 moles of CaSO4 and about (0.5 to 2) + 2n moles of CaO per mole of Al2O3.nSiO2 where n is about 1.5 to about 2.5; and firing the mixture at a temperature between about 1,200*C and about 1,600*C for a residence time of about 1 to about 5 hours.
Claim 18
Dependent Claim
98 words
A process for preparing a fast-setting hydraulic cement which rapidly develops strength and which has a compressive strength of at least about 2,900 p.s.i. within 24 hours after initiation of hydration comprising: forming a mixture of sources respectively of CaO, SiO2, Al2O3 and SO3 in proportions of about 1-3 moles of CaSO4 and about (0.5 to 2) + 2n moles of CaO per mole of Al2O3.nSiO2 where n is about 1.5 to about 2.5; and firing the mixture at a temperature between about 1,200*C and about 1,600*C for a residence time of about 1 to about 5 hours.
Claim 19
Dependent Claim
33 words
The process of claim 15 in which the source materials are in proportions of about 1.75 moles of CaSO4 and about 5.75 moles of CaO per mole of Al2O3.nSiO2 where n is 2.
Claim 20
Dependent Claim
37 words
The process of claim 15 in which the firing is at about 1, 260*C and the proportions are about 1.6-2.1 moles of CaSO4 and about 5.65-5.95 moles of CaO per mole of Al2O3.nSiO2 where n is 2.
Claim 21
Dependent Claim
71 words
The process of claim 15 in which the firing is at about 1, 300*C and the proportions are about in the area enclosed by the equations: 0.7X - 2.29Y + 12.0762 0 0.72X + 0.39Y - 3.1728 0; and 1.42X - 1.9Y + 6.9816 0 wherein Y represents the moles of CaO per mole of Al2O3 and X represents the moles of CaSO4 per mole of Al2O3.nSiO2 where n is 2.
Claim 22
Dependent Claim
37 words
The process of claim 15 in which the firing is at about 1, 350*C and the proportions are about 1.7-2.8 moles of CaSO4 and about 4.75-6.25 moles of CaO per mole of Al2O3.nSiO2 where n is 2.
Claim 23
Dependent Claim
13 words
The process of claim 15 including the step of grinding the resultant clinker.
Claim 24
Dependent Claim
41 words
The process of claim 15 in which CaSO4 is used as source of CaO by decomposition including the steps of forming a mixture of about 7 moles of CaSO4 per mole of Al2O3; and firing the mixture in a reducing atmosphere.
Claim 25
Dependent Claim
18 words
The process of claim 21 in which coke is included in the mixture to provide a reducing atmosphere.
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) | 1978-01-13 | 1978-07-15 | 1979-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-13 | 1982-07-15 | 1983-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-13 | 1986-07-15 | 1987-01-14 | $7700.00 | Window Closed / Lapsed |