US4849282A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Prestressing steel material
Assignee: Sumitomo Electric Industries Ltd
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Filing: 1987-06-15
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Granted: 1989-07-18
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Expires: 2007-06-15
Abstract
Abstract An elongated prestressing steel material for use in the fabrication of prestressed concrete comprises a steel member and an outer coat of many microcapsules each containing a flowable material in its interior.
Inventors
- 👤 Kanji Watanabe
- 👤 Mikio Mizoe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:49
CPC Classifications
E; E04; E04C; E04C5/00; E04C5/08; Y; Y10; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249994; Y10T428/249995; Y10T428/249997; Y10T428/25; Y10T428/254; Y10T428/26; Y10T428/263; Y10T428/29; Y10T428/2913; Y10T428/2927
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
72 words
A method of prestressing concrete, comprising the following steps: adhering an outer coat of a plurality of microcapsules, each of said microcapsules containing a flowable material, to an elongate steel member to provide a coated elongate steel member; placing the coated elongated steel member in concrete such that the microcapsules contact the concrete; and releasing the flowable material in the microcapsules by post tensioning the coated elongate steel member within the concrete.
Claim 2
Independent Claim
72 words
A method of prestressing concrete, comprising the following steps: adhering an outer coat of a plurality of microcapsules, each of said microcapsules containing a flowable material, to an elongate steel member to provide a coated elongate steel member; placing the coated elongated steel member in concrete such that the microcapsules contact the concrete; and releasing the flowable material in the microcapsules by post tensioning the coated elongate steel member within the concrete.
Claim 3
Dependent Claim
22 words
A method according to claim 1, wherein said flowable material is a substance selected from the group consisting of grease and asphalt.
Claim 4
Dependent Claim
40 words
A method according to claim 1, wherein each of said microcapsules is formed of a material selected from the group consisting of resin and gelatin that will be disrupted upon application of an external force elongation exceeding a critical value.
Claim 5
Dependent Claim
15 words
A method according to claim 1, wherein said flowable material is a hardenable flowable material.
Claim 6
Dependent Claim
15 words
A method according to claim 4, wherein the hardenable flowable material is an age-hardening resin.
Claim 7
Dependent Claim
24 words
A method according to claim 4, wherein two different hardenable flowable materials are confined in separate microcapsules and will age-harden when they coalesce together.
Claim 8
Dependent Claim
43 words
A method according to claim 4, 5 or 6, wherein each of the said microcapsules is formed of a material selected from the group consisting of resin and gelatin that will be disrupted upon application of an external force exceeding a critical value.
Claim 9
Dependent Claim
22 words
A method according to claim 4, wherein said microcapsules are coated or installed on the entire outer surface of said steel member.
Claim 10
Dependent Claim
19 words
A method according to claim 1, wherein each of said microcapsules has a diameter of 100 to 300 μm.
Claim 11
Dependent Claim
35 words
A method according to claim 6, wherein one of such hardenable flowable materials is a epoxy resin and the other is a hardening agent selected from the group consisting of diethylenetriamine and higher hydrocarbon diamine.
Claim 12
Dependent Claim
18 words
A method according to claim 1, wherein the thickness of said outer coat is at least 200 μm.
Claim 13
Dependent Claim
65 words
A prestressed concrete structure comprising: a concrete body; an elongate steel member placed in said concrete body; and an outer coat comprising a plurality of microcapsules which are adhered to the steel member by a suitable adhesive agent and which are in contact with the concrete, said microcapsules containing therein a flowable material, said microcapsules rupturing upon post tensioning to yield said prestressed concrete structure.
Claim 14
Dependent Claim
65 words
A prestressed concrete structure comprising: a concrete body; an elongate steel member placed in said concrete body; and an outer coat comprising a plurality of microcapsules which are adhered to the steel member by a suitable adhesive agent and which are in contact with the concrete, said microcapsules containing therein a flowable material, said microcapsules rupturing upon post tensioning to yield said prestressed concrete structure.
Claim 15
Dependent Claim
20 words
A prestressed concrete structure according to claim 12, wherein the thickness of said outer coat is at least 200 μm.
Claim 16
Dependent Claim
24 words
A prestressed concrete structure according to claim 12, wherein said flowable material is a substance selected from the group consisting of grease and asphalt.
Claim 17
Dependent Claim
41 words
A prestressed concrete structure according to claim 12, wherein each of said microcapsules is formed of a material selected from the group consisting of resin and gelatin that will be disrupted upon application of an external force exceeding a critical value.
Claim 18
Dependent Claim
21 words
A prestressed concrete structure according to claim 12, wherein each of said microcapsules has a diameter of 100 to 300 μm.
Claim 19
Dependent Claim
24 words
A prestressed concrete structure according to claim 12, wherein said microcapsules are coated or installed on the entire outer surface of said steel member.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1992-07-17 | 1993-01-16 | 1993-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-17 | 1997-01-16 | 1997-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-17 | 2001-01-16 | 2001-07-18 | $7700.00 | Window Closed / Lapsed |