US4066469A
Expired / Lapsed
US
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Rapid hardening cement
Assignee: Associated Portland Cement Manufacturers Ltd
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Filing: 1976-10-15
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Granted: 1978-01-03
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Expires: 1996-10-15
Abstract
Abstract A gypsum-free ultra-rapid hardening Portland Cement ground to a specific surface area of 3000 to 7000 cm 2 /g and containing a minor proportion of an acid salt of an alkali metal, ammonium or organic base.
Inventors
- 👤 Leslie Edward Shiel
- 👤 Kenneth Wilson Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:19
CPC Classifications
C; C04; C04B; C04B22/00; C04B22/08; C04B2103/00; C04B2103/0004; C04B2111/00; C04B2111/10; C04B2111/1018
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
109 words
A gypsum-free cement composition exhibiting ultra-rapid attainment of high early strength as compared with ordinary Portland cement containing gypsum, and with setting properties which can be regulated, which composition consists essentially of a Portland cement clinker, which does not contain gypsum, ground to exhibit a specific surface of from 3000-7000 cm 2 /g, and at least one acid salt of a base in amount sufficient to impart said ultra-rapid attainment of high early strength, said acid salt of a base being selected from the group consisting of alkali metals, ammonium and organic bases with a phosphorous-free acid and being present in amount of 0.1-10% by weight of said clinker.
Claim 2
Dependent Claim
109 words
A gypsum-free cement composition exhibiting ultra-rapid attainment of high early strength as compared with ordinary Portland cement containing gypsum, and with setting properties which can be regulated, which composition consists essentially of a Portland cement clinker, which does not contain gypsum, ground to exhibit a specific surface of from 3000-7000 cm 2 /g, and at least one acid salt of a base in amount sufficient to impart said ultra-rapid attainment of high early strength, said acid salt of a base being selected from the group consisting of alkali metals, ammonium and organic bases with a phosphorous-free acid and being present in amount of 0.1-10% by weight of said clinker.
Claim 3
Dependent Claim
20 words
A composition according to claim 1, ground to exhibit a specific surface of from 4000 to 6000 cm 2 /g.
Claim 4
Dependent Claim
30 words
A composition as defined in claim 2 wherein said acid salt is selected from the group consisting of bicarbonates, bisulphates and bisulphites of sodium, potassium and ammonium and mixtures thereof.
Claim 5
Dependent Claim
20 words
A composition as defined in claim 1 wherein said acid salt of a base is present in amount of 1.0-5%.
Claim 6
Dependent Claim
20 words
A composition as defined in claim 2 wherein said acid salt of a base is present in amount of 1.0-5%.
Claim 7
Dependent Claim
20 words
A composition as defined in claim 3 wherein said acid salt of a base is present in amount of 1.0-5%.
Claim 8
Dependent Claim
20 words
A composition according to claim 6, ground to exhibit a specific surface of from 4000 to 6000 cm 2 /g.
Claim 9
Independent Claim
128 words
The method of making a gypsum-free cement composition exhibiting ultra-rapid attainment of high early strength as compared with ordinary Portland cement containing gypsum, and with setting properties which can be controlled, which comprises the steps of: a. grinding Portland cement clinker, in the absence of gypsum, to exhibit a specific surface of from 3000-7000 cm 2 /g; b. controlling the hardening rate of said composition by incorporating in said ground clinker from 0.1-10% by weight of at least one acid salt of a base selected from the group consisting of alkali metals, ammonium and organic bases with a phosphorous-free acid; and c. controlling the setting time of said composition by incorporating therein a retarding agent such as hydroxy carboxylic acids and lignosulphonates in amount of 0.05-2% by weight.
Claim 10
Independent Claim
128 words
The method of making a gypsum-free cement composition exhibiting ultra-rapid attainment of high early strength as compared with ordinary Portland cement containing gypsum, and with setting properties which can be controlled, which comprises the steps of: a. grinding Portland cement clinker, in the absence of gypsum, to exhibit a specific surface of from 3000-7000 cm 2 /g; b. controlling the hardening rate of said composition by incorporating in said ground clinker from 0.1-10% by weight of at least one acid salt of a base selected from the group consisting of alkali metals, ammonium and organic bases with a phosphorous-free acid; and c. controlling the setting time of said composition by incorporating therein a retarding agent such as hydroxy carboxylic acids and lignosulphonates in amount of 0.05-2% by weight.
Claim 11
Dependent Claim
23 words
A gypsum-free cement composition having ultra-rapid hardening to high early strength and controlled setting properties made according to the method of claim 8.
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) | 1981-01-02 | 1981-07-04 | 1982-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-02 | 1985-07-04 | 1986-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-02 | 1989-07-04 | 1990-01-03 | $7700.00 | Window Closed / Lapsed |