CA2081493A1 - Method and apparatus for removing exudate from a prestress sheathing - Google Patents
Method and apparatus for removing exudate from a prestress sheathingInfo
- Publication number
- CA2081493A1 CA2081493A1 CA 2081493 CA2081493A CA2081493A1 CA 2081493 A1 CA2081493 A1 CA 2081493A1 CA 2081493 CA2081493 CA 2081493 CA 2081493 A CA2081493 A CA 2081493A CA 2081493 A1 CA2081493 A1 CA 2081493A1
- Authority
- CA
- Canada
- Prior art keywords
- covering
- bell
- slurry
- vacuum
- water
- 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.)
- Abandoned
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
- E04G21/00—Preparing, conveying, or working-up building materials or building elements in situ; Other devices or measures for constructional work
- E04G21/12—Mounting of reinforcing inserts; Prestressing
Landscapes
- Engineering & Computer Science (AREA)
- Architecture (AREA)
- Mechanical Engineering (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
- Manufacturing Of Tubular Articles Or Embedded Moulded Articles (AREA)
- Reinforcement Elements For Buildings (AREA)
Abstract
To eliminate the exudation water formed in a slurry (13) that protects twisted-wire prestress strands (13) inside a vertical covering (3), a bell (9) is placed on an anchor block (7) for the top ends of the strand, a seal (15) is formed inside said bell so that communication between the covering and the bell is possible only via the interstices between the wires in the strands, a point (P) of the covering is connected to a higher supply of slurry (12, 13) via a lateral duct (11), and simultaneously a vacuum is established inside the bell by means of a pump (16).
Description
2asl~s3 METHODS AND APPARATUSES FOR ELIMINATING EXUDATION WATER FROM
PRESTRESS COVERINGS
The invention relates to methods and to apparatuses for eliminating exudation water that comes from cement slurry 5 injected into vertical coverings or more generally coverings or sneaths that include at least a portion that slopes relative to the horizontal, containing prestress strands or cables for structures made of concrete, which water separates from the slurry while the slurry is setting, and collects in the top portions of such coverings.
The invention relates more particularly to the case where the prestress cables in question are constituted by strands or bundles of metal wires (generally twisted together), which wires have at least one end that is bared in order to enable it to be securely clamped in an anchoring jaw.
Permanent contact between water and the bared portions of said strands must naturally be avoided in order to avoid the danger of corrosion, in particular by rust.
That is one of the purposes of injecting a cement slurry into such coverings so as to fill up the empty space in the coverings that is not occupied by strands: the slurry constitutes a protective coating for the bared portions in question.
The above slurry is injected while in the liquid state into a covering from one end thereof, and as soon as it has been injected and while it is subsequently setting, the slurry splits up progressively into two masses, a relatively dense hardened mass and a lighter, liquid mass that corresponds to the water initially present in the slurry and that collects on top of the solidified mass.
When the strands and their coverings are vertical or are inclined to the horizontal, the liquid portion collects in the top of the covering, and when such covered strands are very long (which length may exceed 20 meters, or even 100 meters or more as occurs in concrete off-shore type structures) the length of the portion of each covering that ends up being filled with water after the slurry has set can be as much as several meters. 2asl ~ s3 METHODS AND APPARATUSES FOR ELIMINATING EXUDATION WATER FROM
PRESTRESS COVERINGS
The invention relates to methods and to apparatuses for eliminating exudation water that comes from cement slurry 5 injected into vertical coverings or more generally coverings or sneaths that include at least a portion that slopes relative to the horizontal, containing prestress strands or cables for structures made of concrete, which water separates from the slurry while the slurry is setting, and collects in the top portions of such coverings.
The invention relates more particularly to the case where the prestress cables in question are constituted by strands or bundles of metal wires (generally twisted together), which wires have at least one end that is bared in order to enable it to be securely clamped in an anchoring jaw.
Permanent contact between water and the bared portions of said strands must naturally be avoided in order to avoid the danger of corrosion, in particular by rust.
That is one of the purposes of injecting a cement slurry into such coverings so as to fill up the empty space in the coverings that is not occupied by strands: the slurry constitutes a protective coating for the bared portions in question.
The above slurry is injected while in the liquid state into a covering from one end thereof, and as soon as it has been injected and while it is subsequently setting, the slurry splits up progressively into two masses, a relatively dense hardened mass and a lighter, liquid mass that corresponds to the water initially present in the slurry and that collects on top of the solidified mass.
When the strands and their coverings are vertical or are inclined to the horizontal, the liquid portion collects in the top of the covering, and when such covered strands are very long (which length may exceed 20 meters, or even 100 meters or more as occurs in concrete off-shore type structures) the length of the portion of each covering that ends up being filled with water after the slurry has set can be as much as several meters.
2 2081433 Several solutions have been proposed for r~moving said water and replacing it with slurry, in particular in French patents Nos. 76 26800 (published under No. 2 363 679) and 91 00330.
According to those solutions, the elimination apparatus of the kind in question includes:
firstly a bell that is pla oe d in sealed manner over the anchor block for the top ends of the vertically-extending covered cables in question; and secondly a lateral injection duct connecting a top supply of slurry to a lateral point of the covering, which point is located in the vicinity of the level at which the solid and liquid phases of the slurry meet when the exudation water has finished separating out, which level is generally situated a little below the smaller end of the flare that contains the flared top end of the cable and that runs vertically into the anchor block at the top end of the covering.
In each of those solutions, it is ne oessary to wait for the exudation water coming from the main volume of the slurry in~ected into the covering as a whole to collect in the top of said covering before said water is subsequently expelled through the anchor block by means of ~n additional volume of slurry that is injected via the lateral duct.
The invention proposes a modification of the above solutions and that possesses a certain number of advantages, in particular with respect to simplicity and speed of implementation, and also with respect to the efficiency with which the coverings in guestion are finally filled with slurry.
To this end, according to the present invention, apparatuses of the kind in question for eliminating exudation water are essentially characterized in that they further comprise:
a seal formed on the anchor block inside the bell so that communication is established between the inside volumes of the covering and the bell exclusively via the interstices between the various wires making up the strands; and 2 2081433 Several solutions have been proposed for r ~ moving said water and replacing it with slurry, in particular in French patents Nos. 76 26800 (published under No. 2 363 679) and 91 00 330.
According to those solutions, the elimination apparatus of the kind in question includes:
firstly a bell that is pla oe d in sealed manner over the anchor block for the top ends of the vertically-extending covered cables in question; and secondly to lateral injection duct connecting to top supply of slurry to a lateral point of the covering, which point is located in the vicinity of the level at which the solid and liquid phases of the slurry meet when the exudation water has finished separating out, which level is generally located a little below the smaller end of the flare that contains the flared top end of the cable and that runs vertically into the anchor block at the top end of the covering.
In each of those solutions, it is ne oessary to wait for the exudation water coming from the main volume of the slurry in ~ ected into the covering as a whole to collect in the top of said covering before said water is subsequently expelled through the anchor block by means of ~ n additional volume of slurry that is injected via the lateral duct.
The invention proposed a modification of the above solutions and that possesses a certain number of advantages, in particular with respect to simplicity and speed of implementation, and also with respect to the efficiency with which the coverings in guestion are finally filled with slurry.
To this end, according to the present invention, apparatuses of the kind in question for eliminating exudation water are essentially characterized in that they further included:
a seal formed on the anchor block inside the bell so that communication is established between the inside volumes of the covering and the bell exclusively via the interstices between the various wires making up the strands; and
3 2~1493 a vacuum source connected to the bell so as to suck out therefrom via the above-speclfied interstlces successively the air and then the water contained in the covering.
According to the invention, methods of eliminating exudation water by implementing the above apparatuses, are essentially characterized by the following sequence of steps:
with oommunication between the supply of slurry to be injected and the covering being interrupted, a vacuum is applied inside the bell, thereby evacuating the inside of the covering by sucking out the air initially contained in said covering via the interstices that exist between the wires in the strands making up the cable; then once the degree of vacuum has achieved a satisfactory value, communication is established between the supply of slurry and the covering while a vacuum continues to be applied to the bell, thereby having the combined effects of completely filling the coveri.ng with slurry, and of urging the exudation water from said slurry into the bell, by causing the water to be evacuated through the above interstices and said bell; and finally when no more exudation water is being recovered from the intersti oe s, the vacuum is no longer applied to the bell and communication between the supply of slurry and the covering is interrupted.
At this point in the description, it is appropriate to recall that the following have already been proposed:
firstly expelling the exudation water from the slurry for protecting a prestress cable housed in its covering via the interstices between the various wires composing the top end of the strands constituting said cable, via a "chimney" effect generated by a rising thrust of the slurry while it is being injected ~see French patent No. 2 188 004); and secondly injecting such a slurry into the covering by previously evacuating the inside volume thereof and subsequently putting the covering into communication with a supply of slurry in the liquid state or that is at least sufficiently fluid (see West German patent No. 1 684 437).
However those two technlques had not been operated simultaneously before the present invention and it is only the combination thereof as proposed herein that makes lt possible to eliminate completely and quickly the exudation water of the slurry in question.
In addition to the above main dispositions, the invention also includes certain other dispositions that are preferably used simultaneously and that are described in greater detail below.
A preferred embodiment of the invention is described below with referenoe to the accompanying drawing, which is given by way of non-limiting example.
Figures 1 and 2 of the drawing are diagrams showing apparatus for eliminating exudation water in application of the present invention, respectively during two successive stages of the method implemented for performing said elimination.
Figure 3 is a section on a larger scale through one of the strands included in the above apparatus.
In conventional manner, a very tall concrete structure 1, such as a concrete vessel for a nuclear reactor or a buttress for a dam is reinforced by at least one cable made up of strands 2 which are housed side by side in a covering or sheath 3 that slopes relative to the horizontal or that extends vertically.
Each strand 2 is itself made up of a bundle of metal wires 3 2 ~ 1493 a vacuum source connected to the bell so as to suck out therefrom via the above-speclfied interstlces successively the air and then the water contained in the covering.
According to the invention, methods of eliminating exudation water by implementing the above apparatuses, are essentially characterized by the following sequence of steps:
with oommunication between the supply of slurry to be injected and the covering being interrupted, a vacuum is applied inside the bell, thereby evacuating the inside of the covering by sucking out the air initially contained in said covering via the interstices that exist between the wires in the strands making up the cable; then once the degree of vacuum has achieved a satisfactory value, communication is established between the supply of slurry and the covering while a vacuum continues to be applied to the bell, thereby having the combined effects of completely filling the coveri.ng with slurry, and of urging the exudation water from said slurry into the bell, by causing the water to be evacuated through the above interstices and said bell; and finally when no more exudation water is being recovered from the intersti oe s, the vacuum is no longer applied to the bell and communication between the supply of slurry and the covering is interrupted.
At this point in the description, it is appropriate to recall that the following have already been proposed:
firstly expelling the exudation water from the slurry for protecting a prestress cable housed in its covering via the interstices between the various wires composing the top end of the strands constituting said cable, via a "chimney" effect generated by a rising thrust of the slurry while it is being injected ~ see French patent No. 2 188 004); and secondly injecting such a slurry into the covering by previously evacuating the inside volume thereof and subsequently putting the covering into communication with a supply of slurry in the liquid state or that is at least sufficiently fluid (see West German patent No. 1 684 437).
However those two technlques had not been operated simultaneously before the present invention and it is only the combination thereof as proposed herein that makes it possible to eliminate completely and quickly the exudation water of the slurry in question.
In addition to the above main provisions, the invention also includes certain other provisions that are preferably used simultaneously and that are described in greater detail below.
A preferred embodiment of the invention is described below with referenoe to the accompanying drawing, which is given by way of non-limiting example.
Figures 1 and 2 of the drawing are diagrams showing apparatus for eliminating exudation water in application of the present invention, respectively during two successive stages of the method implemented for performing said elimination.
Figure 3 is a section on a larger scale through one of the strands included in the above apparatus.
In conventional manner, a very tall concrete structure 1, such as a concrete vessel for a nuclear reactor or a buttress for a dam is reinforced by at least one cable made up of strands 2 which are housed side by side in a covering or sheath 3 that slopes relative to the horizontal or that extends vertically.
Each strand 2 is itself made up of a bundle of metal wires
4, 5 (Figure 3) comprising a oe ntral core 4 surrounded by a plurality of wires 5 that are twisted thereabout.
As can be seen clearly in Figure 3, such a bundle leaves small interstices 1 between the various wires 4 and 5, which interstices have cross-sections generally in the form of curvilinear triangles.
The cross-sectional area of the interstices 1 is sufficient to enable them to convey air longitudinally, and also water, but not injected slurry.
The flared top end of each cable is received in a flare 6 or frustoconical sleeve that is connected to the top end of the corresponding cover, and the top ends of the strands 2 are individually anchored in a block 7, by appropriate jaws 8, with each strand going through the block.
20814~3 The block 7 itself rests against the structure 1 via an annular seat, e.g. constituted by a flange 61 extending horizontally outwards from the top end of the flare 6~ and it is covered by a bell 9 that also rests on said flange 6l in sealed manner, and that is in communication with the outside via a top coupling 10.
In addition, a lateral duct 11 embedded in the structure 1 connects a lateral point P of the covering 3 to an outside receptacle 12 that contains the slurry to be injected 13.
The point P is very close to the top end of the covering:
it is disposed at a distance L beneath the anchor block 7, which distan oe generally lies in the range 0.5 meters to 3 meters.
A valve 14 mouited on the top end,of the duct ll, which projects above the structure l, serves to establish communication between said duct and the bottom of the receptacle 12.
In addition, ard in accordan oe with the present invention, a plug 15 or "seal" is formed on the block 7 inside the bell 9 in order to close the block 7 and the jaws 8 carried thereby in sealed manner, apart from the above-mentioned interstices i: to this end, the top ends of the various strands 2 project above the seal 15, as can clearly be seen in Figures 1 and 2.
The seal 15 may be constituted by any appropriate material such as a mortar made of cement or a resin.
In addition, the coupling 10 is connected to a vacuum sour oe 16 such as a vacuum pump having a water collecting tank 17 interposed in the connection.
Under such circumstances, the method proceeds as follows.
With the valve 14 initially closed, the bell 9 is ; evacuated by switching on the vacuum pump 16, thereby sucking the air contained in the covering 3 into the pump 16 via said bell 9 and the tank 17. This volu~e of air is sucked through the interstices i as represented by arrows _ in Figure 1, and then from the bell 9 towards the pump 16 (arrow F).
A relatively high vacuum is thus rapidly established inside the covering 3.
2~ 493 Once the degree of this vacuum is considered as being satisfactory, and for example the pressure inside the covering 3 is no more than about 5 millibars to 20 millibars, the valve 14 is opened.
By opening the valve, the mass of slurry 13 to be injected is put into communication with the vacuum chamber constltuted by the covering 3 and the duct 11. The mass of slurry thus flows immediately under the combined effects of the vacuum and of gravity down the duct 11 to the point P (arrow G) and from that point it flows inside the covering 3 firstly downwards (arrow H) and then once the covering has been filled up to the point P, upwards until the entire covering and its flare 6 have been filled (arrow X).
During this filling, a vacuum continues to be applied to the bell 9 (arrow F).
Experiments have shown that the accumulated effect of said filling (itself due simultaneously to the prior vacuum and to gravity) and of the permanent suction exerted upwards through the intersti oe s i has the effect of producing "forced exudation" of the water contained in the slurry being injected, and of urging said water initially upwards and then through said interstices into the tank 17. This forced upwards expulsion of the exudation water is represented in the bell 9 by arrows g in Figure 2.
Experiments have also shown that after a relatively short period of time T following the opening of the valve 14, no more water is collected from the outlets of the intersti oe s i, which means that all the ~xudation water from the slurry injected into the covering 3 has been eliminated.
This time T is short compared with the time usually required for naturally collecting the exudation water from the slurry at the top of the covering, sinoe said times generally exceed 2 or 3 hours whereas the time T is generally of the order of only a quarter of an hour.
Naturally, as soon as it is observed that no more exudation water is being eliminated, the operation of filling the covering 3 with slurry can be considered as having 2~j81493 terminated, so the valve 14 can be closed, the vacuum pump 16 can be switched off, and the bell 9 and the supply 12 can be recovered for performing further filling operations.
The sealing of the covering thus filled with slurry should then be completed in the interstices i by covering the first seal 15 with a finishing, second seal (not shown) in which the top ends of the strands 2 are this time completely e~bedded.
As a result, whichever embodiment is adopted, a method is obtained that eliminates the exudation water from the protective slurry of prestress cables in their vertical coverings (or coverings that include at least a length that slopes relative to the horizontal) presenting numerous advantages over the prior art, in particular with respect to simplicity, efficiency, and rapidity of implementation.
Naturally, and as can be seen from the above, the invention is not limited in any way to the particular applications and embodiments that have been described in detail; on the contrary, the invention covers any modification thereof, and in particular:
modifications in which a slurry pump is used to raise the supply of slurry to be injected to a level that is higher than the top of the covering to be filled and/or to finish off lnjecting the filler into the covering initially obtained essentially by the combined effects of the vacuum and of - 25 gravity; and modifications in which the covering in question merely has one or more lengths that slope relative to the horizontal, e.g.
extending along a sinuous line that lies in a vertical plane. 4, 5 (Figure 3) comprising a central core 4 surrounded by a plurality of wires 5 that are twisted thereabout.
As can be seen clearly in Figure 3, such a bundle leaves small interstices 1 between the various wires 4 and 5, which interstices have cross-sections generally in the form of curvilinear triangles.
The cross-sectional area of the interstices 1 is sufficient to enable them to convey air longitudinally, and also water, but not injected slurry.
The flared top end of each cable is received in a flare 6 or frustoconical sleeve that is connected to the top end of the corresponding cover, and the top ends of the strands 2 are individually anchored in a block 7, by appropriate jaws 8, with each strand going through the block.
20814 ~ 3 The block 7 itself rests against the structure 1 via an annular seat, eg constituted by a flange 61 extending horizontally outwards from the top end of the flare 6 ~ and it is covered by a bell 9 that also rests on said flange 6l in sealed manner, and that is in communication with the outside via a top coupling 10.
In addition, a lateral duct 11 embedded in the structure 1 connects a lateral point P of the covering 3 to an outside receptacle 12 that contains the slurry to be injected 13.
The point P is very close to the top end of the covering:
it is disposed at a distance L beneath the anchor block 7, which distan oe generally lies in the range 0.5 meters to 3 meters.
A valve 14 mouited on the top end, of the duct ll, which projects above the structure l, serves to establish communication between said duct and the bottom of the receptacle 12.
In addition, ard in accordan oe with the present invention, a plug 15 or "seal" is formed on the block 7 inside the bell 9 in order to close the block 7 and the jaws 8 carried thereby in sealed manner, apart from the above-mentioned interstices i: to this end, the top ends of the various strands 2 project above the seal 15, as can clearly be seen in Figures 1 and 2.
The seal 15 may be constituted by any appropriate material such as a mortar made of cement or a resin.
In addition, the coupling 10 is connected to a vacuum sour oe 16 such as a vacuum pump having a water collecting tank 17 interposed in the connection.
Under such circumstances, the method proceeds as follows.
With the valve 14 initially closed, the bell 9 is ; evacuated by switching on the vacuum pump 16, thereby sucking the air contained in the covering 3 into the pump 16 via said bell 9 and the tank 17. This volu ~ e of air is sucked through the interstices i as represented by arrows _ in Figure 1, and then from the bell 9 towards the pump 16 (arrow F).
A relatively high vacuum is thus rapidly established inside the covering 3.
2 ~ 493 Once the degree of this vacuum is considered as being satisfactory, and for example the pressure inside the covering 3 is no more than about 5 millibars to 20 millibars, the valve 14 is opened.
By opening the valve, the mass of slurry 13 to be injected is put into communication with the vacuum chamber constltuted by the covering 3 and the duct 11. The mass of slurry thus flows immediately under the combined effects of the vacuum and of gravity down the duct 11 to the point P (arrow G) and from that point it flows inside the covering 3 firstly downwards (arrow H) and then once the covering has been filled up to the point P, upwards until the entire covering and its flare 6 have been filled (arrow X).
During this filling, a vacuum continues to be applied to the bell 9 (arrow F).
Experiments have shown that the accumulated effect of said filling (itself due simultaneously to the prior vacuum and to gravity) and of the permanent suction exerted upwards through the intersti oe si has the effect of producing "forced exudation "of the water contained in the slurry being injected, and of urging said water initially upwards and then through said interstices into the tank 17. This forced upwards expulsion of the exudation water is represented in the bell 9 by arrows g in Figure 2.
Experiments also have shown that after a relatively short period of time T following the opening of the valve 14, no more water is collected from the outlets of the intersti oe si, which means that all the ~ xudation water from the slurry injected into the covering 3 has been eliminated.
This time T is short compared with the time usually required for naturally collecting the exudation water from the slurry at the top of the covering, sinoe said times generally exceed 2 or 3 hours whereas the time T is generally of the order of only a quarter of an hour.
Naturally, as soon as it is observed that no more exudation water is being eliminated, the operation of filling the covering 3 with slurry can be considered as having 2 ~ j81493 terminated, so the valve 14 can be closed, the vacuum pump 16 can be switched off, and the bell 9 and the supply 12 can be recovered for performing further filling operations.
The sealing of the covering thus filled with slurry should then be completed in the interstices i by covering the first seal 15 with a finishing, second seal (not shown) in which the top ends of the strands 2 are this time completely e ~ bedded.
As a result, whichever embodiment is adopted, a method is obtained that eliminates the exudation water from the protective slurry of prestress cables in their vertical coverings (or coverings that include at least a length that slopes relative to the horizontal) presenting numerous advantages over the prior art, in particular with respect to simplicity, efficiency, and rapidity of implementation.
Naturally, and as can be seen from the above, the invention is not limited in any way to the particular applications and embodiments that have been described in detail; on the contrary, the invention covers any modification thereof, and in particular:
modifications in which a slurry pump is used to raise the supply of slurry to be injected to a level that is higher than the top of the covering to be filled and / or to finish off injecting the filler into the covering initially obtained essentially by the combined effects of the vacuum and of - 25 gravity; and modifications in which the covering in question merely has one or more lengths that slope relative to the horizontal, eg extending along a sinuous line that lies in a vertical plane.
Claims (2)
a seal (15) formed on the anchor block (7) inside the bell (9) so that communication is established between the inside volumes of the covering (3) and the bell (9) exclusively via the interstices (i) between the various wires making up the strands (2); and a vacuum source (16) connected to the bell so as to suck out therefrom via the above-specified interstices (i) successively the air and then the water contained in the covering (3). 1 / Apparatus for eliminating exudation water from the cement slurry (13) injected into a covering (3) having at least one portion that slopes relative to the horizontal and that contains a prestress cable constituted by strands (2) for a concrete structure (1), the apparatus comprising firstly a bell (9) for placing in sealed manner over the anchor block (7) of one end of the covered cable in question, and secondly a lateral injection duct (11) connecting a higher supply (12) of slurry to a lateral point (P) of the covering, the apparatus being characterized in that it further understood:
a seal (15) formed on the anchor block (7) inside the bell (9) so that communication is established between the inside volumes of the covering (3) and the bell (9) exclusively via the interstices (i) between the various wires making up the strands (2); and a vacuum source (16) connected to the bell so as to suck out therefrom via the above-specified interstices (i) successively the air and then the water contained in the covering (3).
with communication between the supply of slurry to be injected (12, 13) and the covering (3) being interrupted, a vacuum is applied inside the bell (9), thereby evacuating the inside of the covering by sucking out the air initially contained in said covering via the interstices (i) that exist between the wires in the strands making up the cable (2); then once the degree of vacuum has achieved a satisfactory value, communication is established between the supply (12) of slurry and the covering while a vacuum continues to be applied to the bell, thereby having the combined effects of completely filling the covering with slurry by the combined action of the vacuum and of gravity, and of urging the exudation water from said slurry into the bell, by causing the water to be evacuated through the above interstices and said bell; and finally when no more exudation water is being recovered from the interstices, the vacuum is no longer applied to the bell and communication between the supply of slurry and the covering is interrupted. 2 / A method of eliminating exudation water by implementing the apparatus according to claim 1, the method being characterized by the following sequence of steps:
with communication between the supply of slurry to be injected (12, 13) and the covering (3) being interrupted, a vacuum is applied inside the bell (9), thereby evacuating the inside of the covering by sucking out the air initially contained in said covering via the interstices (i) that exist between the wires in the strands making up the cable (2); then once the degree of vacuum has achieved a satisfactory value, communication is established between the supply (12) of slurry and the covering while a vacuum continues to be applied to the bell, thereby having the combined effects of completely filling the covering with slurry by the combined action of the vacuum and of gravity, and of urging the exudation water from said slurry into the bell, by causing the water to be evacuated through the above interstices and said bell; and finally when no more exudation water is being recovered from the interstices, the vacuum is no longer applied to the bell and communication between the supply of slurry and the covering is interrupted.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR9113330 | 1991-10-29 | ||
| FR9113330A FR2682975B1 (en) | 1991-10-29 | 1991-10-29 | METHODS AND DEVICES FOR REMOVAL OF EXUDATION WATER FROM PRESSURE CONDUITS. |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2081493A1 true CA2081493A1 (en) | 1993-04-30 |
Family
ID=9418414
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2081493 Abandoned CA2081493A1 (en) | 1991-10-29 | 1992-10-27 | Method and apparatus for removing exudate from a prestress sheathing |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0540401A1 (en) |
| AU (1) | AU2739592A (en) |
| CA (1) | CA2081493A1 (en) |
| FR (1) | FR2682975B1 (en) |
| NO (1) | NO924167L (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2713690B1 (en) * | 1993-12-10 | 1996-02-23 | Freyssinet Int Stup | Improvements to the methods and devices for using cement grouts to be injected into prestressing sheaths. |
| FR2764923B1 (en) * | 1997-06-20 | 1999-08-27 | Freyssinet Int Stup | PROCESS FOR INJECTING A CEMENT GROUT INTO PRE-STRESS SHEATH |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1684437B1 (en) * | 1967-04-28 | 1972-01-05 | Sager & Woerner | Process for the production of the bond between prestressing steels and ducts in prestressed concrete bodies |
| DE2210226C3 (en) * | 1972-03-03 | 1981-01-15 | Ernst Wilhelm 5894 Halver Steinhauer | Method for completely filling a cavity in a concrete structure and devices for carrying out the method |
| BE795398A (en) * | 1972-06-07 | 1973-05-29 | Stup Procedes Freyssinet | PROCEDURE FOR INJECTING EMPTY SPACES BETWEEN A PRE-STRESSING CABLE COMPOSED OF STRANDS AND THE DUCT CONTAINING IT |
| FR2363679A1 (en) * | 1976-09-06 | 1978-03-31 | Freyssinet Int Stup | Removal of segregated water from reinforced concrete - during casting around terminal reinforcement plate |
-
1991
- 1991-10-29 FR FR9113330A patent/FR2682975B1/en not_active Expired - Fee Related
-
1992
- 1992-10-26 EP EP92402894A patent/EP0540401A1/en not_active Withdrawn
- 1992-10-27 CA CA 2081493 patent/CA2081493A1/en not_active Abandoned
- 1992-10-28 AU AU27395/92A patent/AU2739592A/en not_active Abandoned
- 1992-10-29 NO NO92924167A patent/NO924167L/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| AU2739592A (en) | 1993-05-06 |
| EP0540401A1 (en) | 1993-05-05 |
| NO924167D0 (en) | 1992-10-29 |
| FR2682975A1 (en) | 1993-04-30 |
| FR2682975B1 (en) | 1994-01-28 |
| NO924167L (en) | 1993-04-30 |
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