US3628973A
Expired / Lapsed
US
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Modified portland cement and process
Assignee: Associated Portland Cement Manufacturers Ltd
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Filing: 1970-11-20
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Granted: 1971-12-21
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Expires: 1990-11-20
Abstract
Abstract A modified Portland cement having a high early set strength containing one to thirty percent 11CaO .7A12O3.CaX2where X is a halogen.
Inventors
- 👤 Nathan R Greening
- 👤 Llewellyn E Copeland
- 👤 George J Verbeck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:25
CPC Classifications
C; C04; C04B; C04B7/00; C04B7/32; C04B7/326
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
24 words
The composition of claim 1 wherein the amount of said calcium halo-aluminate in said composition is between about 5 to 30 percent by weight.
Claim 2
Dependent Claim
22 words
The composition recited in claim 1 having added thereto between about 1 to 12 percent by weight calcium sulfate calculated as SO3.
Claim 3
Dependent Claim
11 words
The composition recited in claim 1 in which X is fluorine.
Claim 4
Dependent Claim
11 words
The composition recited in claim 1 in which X is chlorine.
Claim 5
Dependent Claim
72 words
A process of preparing a modified portland cement composition characterized by its ability to develop a high early set strength upon hydration which comprises adding to a portland cement clinker a substantial amount halo-aluminate a calcium halo-aluminate having the formula 11CaO.7Al2O3.CaX2 in which X is halogen in an amount such that the percent of said calcium halo-aluminate in the resulting portland cement composition is between about 1 to 30 percent by weight.
Claim 6
Dependent Claim
91 words
A process of forming a modified portland cement composition characterized by its ability to develop a high early set strength upon hydration which cOmprises subjecting portland cement clinker raw mix including alumina to burning at between 1,275* and 1, 400* C. in the absence of added steam but in the presence of calcium fluoride, the amounts of alumina in the raw mix and the calcium fluoride being sufficient to form in the resulting cement composition from about 1 to 30 percent by weight of a ternary compound having he formula 11CaO.7Al2O3.CaF2.
Claim 7
Dependent Claim
25 words
The process recited in claim 7 wherein the clinker resulting from the burning step is interground with calcium sulfate anhydrite and calcium or magnesium carbonate.
Claim 8
Dependent Claim
60 words
The process of claim 8 in which the relative proportions of the interground ingredients in the resulting product are such that the molar ratio of sulfate (calculated as SO3) to alumina (calculated as Al2O3) is between about 0.6 and 1.0 and the molar ratio of carbonate (calculated as CO2) to alumina (calculated as Al2O3) is between about 0.3 and 1.4.
Claim 9
Dependent Claim
23 words
The process of claim 7 wherein the alumina content of said raw mix is at least 0.5 percent by weight calculated as Al2O3.
Claim 10
Dependent Claim
90 words
A process of forming a modified portland cement composition characterized by its ability to develop a high early set strength upon hydration which comprises subjecting portland cement clinker raw mix including alumina to burning at between 1,380* to 1,510* C. in the absence of added steam but in the presence of calcium chloride, the amounts of alumina in the raw mix and the calcium chloride being sufficient to form in the resulting cement composition from about 1 to 30 percent by weight of a ternary compound having the formula 11CaO.7Al2O3.CaCl2.
Claim 11
Dependent Claim
23 words
The process of claim 11 wherein the alumina content of said raw mix is at least 0.5 percent by weight calculated as Al2O3.
References Cited (Backward Citations)
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US1219315A
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US1677182A
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US1904640A
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US2390138A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-20 | 1975-06-21 | 1975-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-20 | 1979-06-21 | 1979-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-20 | 1983-06-21 | 1983-12-21 | $7700.00 | Window Closed / Lapsed |