Patent US4045533A successfully refreshed from Google Patents.
US4045533A
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Method of manufacturing prestressed reinforced concrete articles
Assignee: Individual
•
Filing: 1973-01-15
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Granted: 1977-08-30
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Expires: 1993-01-15
Abstract
Abstract A method of making stressed concrete articles made from a cement containing as an additive to portland cement a mixture of alumina cement, calcium sulfate and ground caustic lime, the method including hydrothermal treatment at 50° C or above followed by curing in cold water for several days.
Inventors
- 👤 Viktor Vasilievich Mikhailov
- 👤 Semen Lvovich Litver
- 👤 Alexandr Konstantinovich Karasev
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:21
CPC Classifications
C; C04; C04B; C04B40/00; C04B40/02; C04B40/0277; C04B40/0286; B; B28; B28B; B28B1/00; B28B21/00; C04B28/00; C04B28/02; C04B28/06; C04B28/065; Y; Y10; Y10S; Y10S264/00; Y10S264/43; Y10S264/59
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
89 words
A method of manufacturing prestressed reinforced concrete articles, consisting essentially of the following operations: moulding the articles from a concrete containing a stressing cement mixture of Portland cement with an added expanding component consisting essentially of a mixture of calcium sulphate, calcium aluminates and calcium oxide; curing the articles until they acquire a stripping strength; stripping said articles, subjecting said articles to hydrothermal treatment under water at a temperature which is not below 50° C for 1-4 hours, and subsequently keeping said articles in cold water for 3-4 days.
Claim 2
Independent Claim
89 words
A method of manufacturing prestressed reinforced concrete articles, consisting essentially of the following operations: moulding the articles from a concrete containing a stressing cement mixture of Portland cement with an added expanding component consisting essentially of a mixture of calcium sulphate, calcium aluminates and calcium oxide; curing the articles until they acquire a stripping strength; stripping said articles, subjecting said articles to hydrothermal treatment under water at a temperature which is not below 50° C for 1-4 hours, and subsequently keeping said articles in cold water for 3-4 days.
Claim 3
Dependent Claim
22 words
A method according to claim 1, wherein the hydrothermal treatment at a temperature of 50°-90° C is carried out during 2-4 hours.
Claim 4
Dependent Claim
22 words
A method according to claim 1, wherein the hydrothermal treatment at a temperature of 90°-100° C is carried out during 1-2 hours.
Claim 5
Dependent Claim
38 words
A method as claimed in claim 1 wherein the ingredients of said stressing cement consist of 62% by weight Portland cement, 20% by weight alumina cement, 13% by weight calcium sulfate and 5% by weight ground caustic lime.
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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) | 1980-08-29 | 1981-02-28 | 1981-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-29 | 1985-02-28 | 1985-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-29 | 1989-02-28 | 1989-08-30 | $7700.00 | Window Closed / Lapsed |