US4494990A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cementitious composition
Assignee: ASH Grove Cement Co
•
Filing: 1983-07-05
•
Granted: 1985-01-22
•
Expires: 2003-07-05
Abstract
Abstract An improved cementitious composition is the subject of the present invention. The composition comprises 25-60 weight percent cement component. The cement component is 3 to 50 weight per pozzolan. The pozzolan should have a sulfate reactivity factor of no greater than 12 utilizing a function obtained from the Dunstan formula. The composition is 40 to 75 percent by weight alpha gypsum (calcium sulfate hemihydrate). Various additives may be included to enhance the performance of the composition. These include polymer modifiers, a water reducing agent, a set retarding agent and a set accelerating agent.
Inventors
- 👤 Harry A. Harris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:23
CPC Classifications
C; C04; C04B; C04B28/00; C04B28/14; C04B28/145; C04B28/146; C04B2103/00; C04B2103/10; C04B2103/12; C04B2103/20; C04B2103/22; C04B2103/30; C04B2103/302; C04B2111/00; C04B2111/60; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/91
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
71 words
A cementitious composition comprising: about 25-60 weight percent of a cement component selected from the group comprising Type I and Type II portland cement, said cement component comprising about 3-50 weight percent pozzolan having a sulfur reactivity factor of 12 or less; about 40 to 75 weight percent calcium sulfate hemihydrate; and about 1 to 20% by weight of a compatible polymer modifier, based on the weight of said cement component.
Claim 2
Dependent Claim
71 words
A cementitious composition comprising: about 25-60 weight percent of a cement component selected from the group comprising Type I and Type II portland cement, said cement component comprising about 3-50 weight percent pozzolan having a sulfur reactivity factor of 12 or less; about 40 to 75 weight percent calcium sulfate hemihydrate; and about 1 to 20% by weight of a compatible polymer modifier, based on the weight of said cement component.
Claim 3
Dependent Claim
21 words
A cementitious composition as set forth in claim 1, wherein is included an effective quantity of a compatible water reducing agent.
Claim 4
Dependent Claim
21 words
A cementitious composition as set forth in claim 1 wherein is included an effective quantity of a compatible set retarding agent.
Claim 5
Dependent Claim
21 words
A cementitious composition as set forth in claim 3, wherein is included an effective quantity of a compatible set accelerating agent.
Claim 6
Dependent Claim
29 words
A cementitious composition as set forth in claim 4, wherein is included about 0.3 to 2 weight percent water reducer, based on the total weight of the dry components.
Claim 7
Dependent Claim
51 words
A cementitious composition as set forth in claim 5, wherein is included up to about 0.5 weight percent of a set retarding agent, based on the quantity of said cement component and up to about 0.5 weight percent of a set accelerating agent, based on the quantity of said cement component.
Claim 8
Dependent Claim
89 words
An additive for either of Type I and Type II portland cement to increase the life and durability of said cement, said additive comprising: about 3-50 weight percent pozzolan, relative to the weight of said cement, said pozzolan having a sulfur reactivity factor of twelve or less; about 50-97 weight percent calcium sulfate hemihydrate, relative to the combined weight of said portland cement and said pozzolan; and about 2 to 40 weight percent of a compatible polymer modifier, based on the combined weight of said pozzolan and said cement.
Claim 9
Dependent Claim
89 words
An additive for either of Type I and Type II portland cement to increase the life and durability of said cement, said additive comprising: about 3-50 weight percent pozzolan, relative to the weight of said cement, said pozzolan having a sulfur reactivity factor of twelve or less; about 50-97 weight percent calcium sulfate hemihydrate, relative to the combined weight of said portland cement and said pozzolan; and about 2 to 40 weight percent of a compatible polymer modifier, based on the combined weight of said pozzolan and said cement.
Claim 10
Dependent Claim
28 words
An additive as set forth in claim 7, wherein is included about 0.3 to 4 weight percent water reducer, based on the total weight of the dry components.
Claim 11
Dependent Claim
56 words
An additive as set forth in claim 8, wherein is included up to about 1.0 weight percent of a set retarding agent, based on the combined weight of said cement and said pozzolan and up to about 1.0 weight percent of a set accelerating agent, based on the combined weight of said cement and said pozzolan.
References Cited (Backward Citations)
US2362060A
Cited
US1255236A
Cited
US3411924A
Cited
US3565648A
Cited
US3582376A
Cited
US3847635A
Cited
US4067939A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-22 | 1988-07-23 | 1989-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-22 | 1992-07-23 | 1993-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-22 | 1996-07-23 | 1997-01-22 | $7700.00 | Window Closed / Lapsed |