GB2209791A - Removal of forces in pre-tensioned or cost tensioned tendons in concrete prior to demolition - Google Patents
Removal of forces in pre-tensioned or cost tensioned tendons in concrete prior to demolition Download PDFInfo
- Publication number
- GB2209791A GB2209791A GB8718928A GB8718928A GB2209791A GB 2209791 A GB2209791 A GB 2209791A GB 8718928 A GB8718928 A GB 8718928A GB 8718928 A GB8718928 A GB 8718928A GB 2209791 A GB2209791 A GB 2209791A
- Authority
- GB
- United Kingdom
- Prior art keywords
- demolition
- tendons
- tensioned
- forces
- explosives
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
- E04G23/00—Working measures on existing buildings
- E04G23/08—Wrecking of buildings
Landscapes
- Engineering & Computer Science (AREA)
- Architecture (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Mechanical Engineering (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Working Measures On Existing Buildindgs (AREA)
Abstract
When demolishing prestressed concrete structures consideration must be given to the large forces that exist in the steel tendons. Where the demolition is taking place remote from other buildings explosives may be used to destroy the structure. Where demolition is taking place within an urban environment explosives cannot be used. In the proposed method relaxation of the tensile forces is undertaken with the application of a voltage across the ends of the tendons. The heating of the tendons produces strain in the tendons which is of opposite sign to that caused by the original applied stressing. The demolition can than take place without the risk of dangerous release of prestressed forces. <IMAGE>
Description
REMOVAL OF FORCE IN THE CABLES OF A PRESTRESSED BESM '
Description of Invention
The invention consists of a method whereby the existing tensile forces within prestressed or post-tensioned beams can be released prior to such units being demolished.
The effects of the electric current in the bars or cables will cause the force in the cable to be drastically reduced thereby enabling work to break up the beam being carried out in safety.
The currents in the cables or bars will heat them up thereby causing
(1) Loss of strength in the cables
(2) Loss of strain in the cables
(3) Loss of bond with surrounding concrete.
Claims (1)
- CLAIMThe procedure described is to enable the force in a pretensioned beam to be removed prior to demolition.Where existing beams are demolished in open country the use of explosives can be carried out. In the town situation however explosives are not permitted and the method described, it is claimed, will provide an answer.The demolition of post tensioned structures is in its infancy but there will be increasing member of such demolitions of this type of structure in the future.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB8718928A GB2209791A (en) | 1987-08-11 | 1987-08-11 | Removal of forces in pre-tensioned or cost tensioned tendons in concrete prior to demolition |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB8718928A GB2209791A (en) | 1987-08-11 | 1987-08-11 | Removal of forces in pre-tensioned or cost tensioned tendons in concrete prior to demolition |
Publications (2)
Publication Number | Publication Date |
---|---|
GB8718928D0 GB8718928D0 (en) | 1987-09-16 |
GB2209791A true GB2209791A (en) | 1989-05-24 |
Family
ID=10622090
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB8718928A Withdrawn GB2209791A (en) | 1987-08-11 | 1987-08-11 | Removal of forces in pre-tensioned or cost tensioned tendons in concrete prior to demolition |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB2209791A (en) |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1240185A (en) * | 1967-10-21 | 1971-07-21 | Fuji Motors Corp | Improvements in demolition methods |
GB1542885A (en) * | 1977-06-24 | 1979-03-28 | Redpath Dorman Long Ltd | Electrical de-tensioning |
-
1987
- 1987-08-11 GB GB8718928A patent/GB2209791A/en not_active Withdrawn
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1240185A (en) * | 1967-10-21 | 1971-07-21 | Fuji Motors Corp | Improvements in demolition methods |
GB1542885A (en) * | 1977-06-24 | 1979-03-28 | Redpath Dorman Long Ltd | Electrical de-tensioning |
Also Published As
Publication number | Publication date |
---|---|
GB8718928D0 (en) | 1987-09-16 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |