US4256504A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fly ash-based cement
Assignee: United States, AS REPRESENTED BY SECERTARY OF INTERIOR
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Filing: 1979-10-16
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Granted: 1981-03-17
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Expires: 1999-10-16
Abstract
Abstract A cement composition comprising a high calcium-content fly ash and calcium sulfate, and mortar and concrete compositions containing the cement.
Inventors
- 👤 Edwin R. Dunstan, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:08
CPC Classifications
C; C04; C04B; C04B28/00; C04B28/14; C04B7/00; C04B7/24; C04B7/26; Y; Y02; Y02P; Y02P40/00; Y02P40/10; Y02W; Y02W30/00; Y02W30/50; Y02W30/91; Y10; Y10S; Y10S106/00; Y10S106/01
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
37 words
A cement composition consisting essentially of (1) a major proportion of a fly ash having a calcium content greater than about 20 percent by weight and (2) about 5 to 15 percent by weight of calcium sulfate.
Claim 2
Dependent Claim
37 words
A cement composition consisting essentially of (1) a major proportion of a fly ash having a calcium content greater than about 20 percent by weight and (2) about 5 to 15 percent by weight of calcium sulfate.
Claim 3
Dependent Claim
12 words
The composition of claim 1 in which the calcium sulfate is anhydrous.
Claim 4
Dependent Claim
12 words
The composition of claim 2 in which the calcium sulfate is anhydrite.
Claim 5
Dependent Claim
20 words
A mortar composition comprising a major proportion of sand and a minor proportion of the cement composition of claim 1.
Claim 6
Dependent Claim
23 words
The concrete composition comprising a major proportion of sand and an aggregate and a minor proportion of the cement composition of claim 1.
References Cited (Backward Citations)
US2803556A
Cited
US3854968A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-16 | 1984-09-15 | 1985-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-16 | 1988-09-15 | 1989-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-16 | 1992-09-15 | 1993-03-17 | $7700.00 | Window Closed / Lapsed |