US4160674A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Early high-strength portland cement and method of manufacture
Assignee: Lone Star Industries Inc
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Filing: 1978-01-30
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Granted: 1979-07-10
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Expires: 1998-01-30
Abstract
Abstract A cement with rapid strength gain having normal setting and volume change characteristics and its method of manufacture are disclosed. The cement has substantially all particles over 20 microns removed which advantageously results in higher early strength than normal portland cements. This is important in the prestress and precast concrete industry, and early high-strength cement is desirable for other uses such as patching or resurfacing highways and airport runways or in operations where early form removal is desired. The use of chlorides or other accelerators is unnecessary to obtain early high strengths; although, these and plasticizers can be used if desired.
Inventors
- 👤 James L. Sawyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 03:56
CPC Classifications
C; C04; C04B; C04B7/00; C04B7/02; C04B7/36; C04B7/48; C04B7/52; C04B7/527
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
33 words
An early high-strength cement having substantially all of its particles of a size of 20 microns and smaller, the cement having setting and volume change characteristics normal for and typical of portland cement.
Claim 2
Dependent Claim
33 words
An early high-strength cement having substantially all of its particles of a size of 20 microns and smaller, the cement having setting and volume change characteristics normal for and typical of portland cement.
Claim 3
Dependent Claim
8 words
The cement of claim 1 including, a plasticizer.
Claim 4
Dependent Claim
8 words
The cement of claim 1 including, an accelerator.
Claim 5
Independent Claim
37 words
A method of producing an early high-strength cement having setting and volume change characterstics normal for and typical of portland cement comprising, removing substantially all particles from a portland cement of a size greater than 20 microns.
Claim 6
Independent Claim
37 words
A method of producing an early high-strength cement having setting and volume change characterstics normal for and typical of portland cement comprising, removing substantially all particles from a portland cement of a size greater than 20 microns.
Claim 7
Dependent Claim
38 words
The method of claim 4 including, grinding at least some of the particles of cement of a size greater than 20 microns to a size of 20 microns and smaller and blending the latter with the cement particles.
Claim 8
Dependent Claim
14 words
The method of claim 4 including, blending a plasticizer with the early high-strength cement.
Claim 9
Dependent Claim
14 words
The method of claim 4 including, blending an accelerator with the early high-strength cement.
Claim 10
Independent Claim
61 words
A method of producing an early high-strength cement having setting and volume change characteristics normal for and typical of portland cements comprising, grinding a portland cement feed to particle sizes typical of an ASTM Type III portland cement, and separating cement particles so that essentially all particles of a size greater than 20 microns are removed from the Type III feed.
Claim 11
Independent Claim
61 words
A method of producing an early high-strength cement having setting and volume change characteristics normal for and typical of portland cements comprising, grinding a portland cement feed to particle sizes typical of an ASTM Type III portland cement, and separating cement particles so that essentially all particles of a size greater than 20 microns are removed from the Type III feed.
Claim 12
Dependent Claim
19 words
The method of claim 8 including, combining the separated particles with an regrinding them with the portland cement feed.
Claim 13
Independent Claim
41 words
A method of producing an early high-strength cement having setting and volume change characteristics normal for and typical of portland cements comprising, blending clinker and gypsum particles of a size of 20 microns and smaller to form the early high-strength cement.
Claim 14
Independent Claim
41 words
A method of producing an early high-strength cement having setting and volume change characteristics normal for and typical of portland cements comprising, blending clinker and gypsum particles of a size of 20 microns and smaller to form the early high-strength cement.
Claim 15
Dependent Claim
14 words
The method of claim 10 including, adding an accelerator to the early high-strength cement.
Claim 16
Dependent Claim
14 words
The method of claim 10 including, adding a plasticizer to the early high-strength cement.
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) | 1982-07-09 | 1983-01-08 | 1983-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-07-09 | 1987-01-08 | 1987-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-07-09 | 1991-01-08 | 1991-07-10 | $7700.00 | Window Closed / Lapsed |