EP1540104B1 - Filtering wall for expendable formwork, means for making said filtering wall and formwork equipped with same - Google Patents

Abstract

The invention concerns a filtering wall designed for an expendable formwork comprising a lattice formed by assembling flexible warp and weft yarns, the lattice being stretched on an undeformable structure. The filtering wall is characterized in that some of the warp yarns are more resistant than other warp yarns, the lattice being stretched by traction solely exerted on the more resistant warp yarns and in that it comprises tension maintaining means for maintaining the tension associating the more resistant yarns with the undeformable structure, the tension maintaining means delimiting a larger mesh than the one resulting from the initial interlacing of the warp and weft yarns.

Description

The invention relates to a filter wall of a lost formwork.

It also relates to the formwork equipped with the filtering wall and to the manufacturing process.

It also relates to the means of manufacturing the filter wall.

The realization of concrete structure is made formwork means of two types.

The first type includes reusable forms.

These form a sealed rigid pocket in which a concrete is introduced.

The formwork walls are formed from steel sheets fixed to a supporting structure, see for example FR 2 712 016 A .

• un poids important des coffrages pour résister à la poussée hydrostatique,
• l'habitude d'utiliser des bétons à prise rapide dont les contraintes de résistance sont au delà ce qui est nécessaire etc .....

This type of formwork has many disadvantages, namely:

• a significant weight of the formwork to resist the hydrostatic thrust,
• used to use quick-setting concrete whose strength constraints are beyond what is needed etc .....

To provide a solution to these various problems, appeared the forms of the second type namely the lost formwork with filter walls.

The concept of these filter walls has been developed to lead to different products ( FR-A-2675181 and FR-A-2647839 ).

These filtering walls in particular make it possible to reduce the weight of the formwork.

The composite "formwork / filling" has improved mechanical characteristics compared to a veil made by traditional means.

The first formwork used: mainly expanded metal to achieve the desired permeability of the formant skin.

To achieve the formwork skin of a formwork wall, it is then necessary to assemble several expanded metal plates to obtain the desired surface.

Furthermore, in these types of formwork, part of the metal structure not under regulatory coating presents risks for durability.

For this reason, the metal structure can not be taken into account in the calculations of the structure.

In addition, the metal skin deployed, even protected against corrosion, can in some cases be the cause of claims due to corrosion phenomena.

In order to overcome these disadvantages, a lost formwork with filtering skin is known ( FR-A-2800109 ) which, instead of the expanded metal, uses a lattice or broad-mesh fabric obtained by interlacing warp yarns with weft yarns.

The mesh size of the mesh is defined according to the aggregates and the desired filtering.

According to this solution, the mesh being flexible.

When attached to the formwork reinforcement, it is tensioned in two perpendicular directions to obtain a uniform tension of the warp and weft threads in both directions.

In addition, spacers keep the formwork skin away from the frame.

This formwork is criticized in particular for overabundant lattice consumption and lattice locations that interfere with the filling of the formwork.

Indeed, a part of the trellis penetrates into the volume to be filled and this poses a difficulty.

The invention proposes to remedy the aforementioned drawbacks.

• d'une part, certains des fils de chaîne sont plus résistants que les autres fils de chaîne, la tension du treillis étant créée alors par traction uniquement sur ces fils de chaîne plus résistants et,
• d'autre part, elle comprend des moyens de maintien d'une tension associant les fils de chaînes plus résistants à la structure indéformable, ces moyens de maintien d'une tension délimitant une maille plus grande que celle résultant du croisement inutile des fils de chaîne et de trame.

For this purpose, the subject of the invention is a filter wall intended for a lost formwork comprising a lattice formed by assembling flexible wires of warp and weft, this lattice being stretched over a so-called indeformable structure, this filtering wall being characterized in that:

• on the one hand, some of the warp yarns are stronger than the other warp yarns, the tension of the lattice then being created by pulling only on these more resistant warp yarns and,
• on the other hand, it comprises means for maintaining a tension associating the warp yarns more resistant to the dimensionally stable structure, these means of maintaining a tension delimiting a larger mesh than that resulting from the unnecessary crossover of the warp yarns. and frame.

The invention also relates to the formwork equipped with the formwork wall and the manufacturing means of said formwork wall.

• figure 1 : l'installation pour la mise en oeuvre du procédé,
• figure 2 : un détail de l'installation,
• figure 3 : une paroi filtrante,
• figure 4 : une représentation de la déformation du treillis,
• figure 5 : un moyen de liaison ou cavalier,
• figure 6 : une coupe d'une barre de pression,
• figure 7 : une coupe d'une barre d'appui,
• figure 8 : le poste de mise en place des barres de pression,
• figure 9 : une vue en plus gros plan d'un détail de la figure 8,
• figure 10 : le rouleau vu de face,
• figure 11 : le rouleau vu de côté,
• figure 12 : le contre-rouleau vu en perspective,
• figure 13 : les moyens de mise en tension amont,
• figure 14 : un détail de la mise en place des barres d'appui,
• figure 15 : l'assemblage terminé vu en coupe.

The invention will be better understood using the following description given by way of non-limiting example, with reference to the attached drawing which schematically shows:

• figure 1 : the installation for the implementation of the process,
• figure 2 : a detail of the installation,
• figure 3 : a filtering wall,
• figure 4 : a representation of the deformation of the lattice,
• figure 5 : a link or jumper,
• figure 6 : a section of a pressure bar,
• figure 7 : a cut of a grab bar,
• figure 8 : the position of setting up the pressure bars,
• figure 9 : a closer view of a detail of the figure 8 ,
• figure 10 : the roll seen from the front,
• figure 11 : the roll seen from the side,
• figure 12 : against the roller seen in perspective,
• figure 13 : the upstream tensioning means,
• figure 14 : a detail of the placement of the grab bars,
• figure 15 : the finished assembly seen in section.

Referring to the drawing, there is a filter wall 1 for equipping a lost formwork.

The formwork wall acts as a filter and depending on the size of the mesh allows to evacuate the excess moisture.

Conventionally, this filtering wall comprises a lattice 2 formed by assembling flexible warp yarns 2A, 2B and weft 2C, this lattice being stretched over a so-called indeformable structure.

Of course, the term indeformable should be taken in its strict sense but, in the sense, where the deformation related to the tension is extremely weak.

This filtering wall is then fixed on a support structure to determine a volume with another wall formwork.

• d'une part, certains 2A des fils de chaîne 2A,2B sont plus résistants que les autres fils de chaîne 2B, la tension du treillis 2 étant créée alors par traction uniquement sur ces fils (2A) de chaîne plus résistants et
• d'autre part, elle comprend des moyens 3,4,5 de maintien de la tension associant les fils de chaînes plus résistants à la structure indéformable, ces moyens 3,4,5 de maintien d'une tension délimitant une maille plus grande que celle résultant du croisement initial des fils de chaîne et de trame 2C.

According to a characteristic of this filtering wall:

• on the one hand, some 2A chain son 2A, 2B are stronger than other warp son 2B, the tension of the lattice 2 being created then by traction only on these son (2A) more resistant chain and
• on the other hand, it comprises means 3,4,5 for maintaining the tension associating the son of chains more resistant to the indeformable structure, these means 3,4,5 for maintaining a tension delimiting a mesh larger than that resulting from the initial crossing of the warp and weft threads 2C.

The voltage and therefore the deformation is determined between two consecutive voltage maintenance means.

More precisely, the principle does not consist in exerting a tension between the ends of the lattice and then in setting up the holding means but, in contrast, fixing one end of the lattice with holding means and then exerting a tension force to fix the latching elements. following holding means.

By relying on these new fixed points, one exerts a new tension and locks the mesh with tensioning means and so on.

By doing so, we get the same tension in each mesh and we define the mesh size.

The tension exerted on the stronger threads, the warp and weft threads located in the previously defined mesh will be arranged according to an iso-constrained repair as shown in FIG. figure 4 .

The mesh is defined by four points A1, A2, B1, B2, that before putting in tension.

When only the points B1 and B2 are brought into B'1 and B'2, there is a deformation of the weft threads (finer lines) which will curl with a neutral weft yarn in the middle of the stitch.

This arrangement distributes the stresses in a decreasing manner from the edge of the mesh, which will allow, under pressure, increasing deformations towards the center of the mesh.

The formwork face defined by a mesh, under the pressure of concrete, is no longer flat but curved.

This allows to optimize the amount of plaster used then to obtain a finished face.

The value of the deformation is determined by the ratio between the elasticity of the son 2A more resistant compared to other son 2B.

For each mesh to be independent, the resistant wire will not be common to two meshes side by side and, therefore, the mesh will include pairs of resistant wires 2A.

The distance between the resistant wires of a pair will depend on the means of maintaining the voltage.

These resistant son 2A are either larger son or another material, or more generally consist of a group of close son.

• d'un coté du treillis, des barres 4 dites de pression qui s'étendent selon l'un des axes du treillis,
• de l'autre coté du treillis 2, des barres 5 dites d'appui qui s'étendent selon une direction perpendiculaire aux barres de pression et,
• aux coins des mailles, des moyens 3 de liaison des barres entre elles formant notamment à ces points de liaison une pince bloquant le treillis.

The means 3,4,5 for maintaining the voltage comprise:

• on one side of the trellis, said pressure bars 4 which extend along one of the axes of the trellis,
• on the other side of the mesh 2, said support bars 5 which extend in a direction perpendicular to the pressure bars and,
• at the corners of the meshes, means 3 for connecting the bars together forming in particular at these connection points a clamp blocking the lattice.

These bars 4,5 and these connecting means 3 then constitute the dimensionally stable structure.

The lattice is not laid on a pre-formed dimensionally stable structure, but this structure is constructed at the same time as the filtering wall.

In order to improve the locking of the lattice at the four corners of the mesh, the so-called pressure bar 4 may comprise splines 4A.

This pressure bar 4 is triangular in shape and the outer face of the base has splines 4A.

This pressure bar has an axial cavity 4B to give it flexibility.

The support bars 5 will be in pairs, that is to say a connecting means 3 is hooked on a pressure bar and two support bars.

We will now describe in more detail a connection means 3. It is furthermore specified that in order to prevent any risk of disorders resulting from unclogging of the elements during transport, this device may be completed by a positive locking device, a gluing or welding.

This connecting means is a jumper for overlapping the pressure bar.

This jumper comprises two legs 3A bearing a thrust face 3B for the pressure bar and, externally, on each of the outer faces of the legs, a support plane 3C for the support bars.

The pressure bar slips between the rider's legs.

A 3D lock prevents the grab bars from slipping sideways.

The 3D lock constituted by a boss is adjacent to one of the support planes 3C.

This support bar is forcibly rotated around its base.

It should be noted, for this purpose, that this support bar thus has rounded faces and a flexibility allowing elastic deformation.

Sectional view, it is in the embodiment in the form of an eight.

Possible cavities give the desired compressibility.

This is also of interest because these pressure and support bars can be delivered wound on a reel.

During manufacture, use the top of the rider and the outer face as a tooth to advance the wall formwork.

It should be noted that the ends of the legs carry lateral notches 3E to anchor on a "Tor" iron of the supporting structure of the formwork.

For the manufacture of these filtering walls, a set of means is used.

• un treillis 2 enroulé sur un axe servant de source 20 d'approvisionnement,
• en aval de cette source, un ensemble 30 de mise en tension et,
• un ensemble 40 de mise en place de la structure indéformable.

These means include:

• a lattice 2 wound on an axis serving as a source of supply,
• downstream of this source, a set 30 of tensioning and,
• a set 40 of implementation of the indeformable structure.

A cutting station 50 at the appropriate length is provided downstream of the assembly stations of the filtering wall.

The installation of the indeformable structure consists in progressively positioning, on the tensioned net, the connecting means 3 and then setting up the pressure bar 4 and the supporting bars 5.

The means for creating the lattice tension are divided into two so-called tensioning zones 30A, 30B which are distributed on both sides of the tool 41. One is arranged just behind the lattice wound on its axis. and the other at the level of the trellis equipped and thus finished.

The tensioning means exert a traction force on the lattice then locked in translation by one of the devices of the tool 41.

The tensile force is determined by the number of meshes between the two tensioning zones to be proportional to the desired elongation of a mesh.

Locking in translation of the lattice located at the downstream tensioning zone 30B comprises a roller 31 and a counter-roll 32, each being provided with grooves 33 able to allow the riders to pass freely.

These roll and against-roll pinch the lattice. A constant torque drive device for example, allows to apply on the warp son 2A and 2B a predetermined constant effort.

These roller and against roller are motorized and can progressively advance the trellis.

The roller and / or the counter-roller may consist of rollers aligned on an axis.

The roller is incidentally mounted on arms 100.

The outer face of the rollers and / or the roll and against-roller will be elastically deformable material to be in sufficient mesh with the mesh.

The diameter will be set to engage a sufficient surface length of lattice.

At the level of the upstream tensioning zone 30A, in a preferred embodiment of the advance and the tension of the trellis, the tensioning means consist of a set of two fixed rollers 34,35 between which is located a roller 36 movable between two positions, one high triggering the unwinding of the mandrel on which is wound the lattice and the other low triggering the stop of the mandrel.

The lattice 2 then forms a V e.

The upstream traction force on the trellis is given either by the simple weight of the mobile roll 36, or this weight is completed by springs or other traction means such as jacks etc ...

The voltage is thus determined by the means distributed upstream of the tool 41.

Downstream of the upstream tensioning zone 30A which in particular controls the unwinding of the lattice of its support on which it is wound, there is a device 41 for advancing the lattice and laying the connection means in the form of a jumper.

This laying device consists of wheels 42 distributed along an axis transverse to the direction of movement of the lattice.

There are as many wheels 42 as riders to place transversely.

All the wheels 42, integral in rotation, are driven by a suitable irreversible device (stepper motor for example) which allows a rotation corresponding to a pitch of the trellis.

Each wheel 42 whose circumference is a multiple of the mesh size regularly has notches 43 able to house the head of each connecting means.

Laterally at these wheels and at the level of the notches, the device comprises guides 44 for the pressure bars which must be introduced into the heads of the riders.

These guides therefore have a groove 45 of complementary shape to the outer face of the pressure bars.

In fact, the guides also serve to assemble the wheels together.

To introduce these pressure bars, you must first align the jumpers because they are not sufficiently maintained by the lattice and the shape of the notches.

For this purpose, the machine comprises a device 46 for aligning the set of jumpers located on an axis.

This alignment device comprises an axis 47 on which are mounted pairs of disks 48 spaced apart, each pair of disks being intended to wedge laterally a jumper and the part of the axis located between two disks of a pair, s partially engage the rider's legs.

We see that these discs 49 flanks beveled to facilitate the centering of the rider.

60 teeth carried by the wheels 41 are used to position, advance and immobilize the lattice on said disks.

The installation of the jumpers is done from below in the represented installation.

A positioning is thus obtained along both axes, the time to introduce the pressure bar which comes from a profile wound on a drum.

The supply of the pressure bar 4 is as follows.

The profile from a coil is driven by pressure rollers 70 to a first stop 71.

When the alignment device is in position, the first stop 71 is retracted and the pressure rollers 70 push the profile 4 through the jumpers 3 guided by the guides 44, until a second stop 72.

The section 4 is then cut and the first stop is then put back in place.

As these pressure bars are put in place, the grab bars must be placed.

To do this, these support bars 5, wound on a reel, are unrolled progressively flat and then rotated 90 ° to come anchor self-stable position on the rider.

The machine will therefore include a device for progressively unwinding the sections 5 and a means for putting them in place.

In a first step, the support bars 5 are guided in such a way as to rest on the support planes of the connecting means 3.

The two support bars 5 then form a Vee.

A mechanical means 80 tilts the support bars towards the connecting means 3.

In the preferred embodiment, use is made of a clamp 80 whose two jaws 81 come closer together.

By elastic deformation of the pressure bar and the support bars, it is then placed these support bars in the self-stable position and ensures the clamping of the mesh.

It can be seen that the action / reaction forces exerted on the support bars are inclined with respect to the median axis of the rider.

Thus, from continuous elements, trellis, support and pressure bars, it is possible to form a filtering wall of appropriate length which is only cut off at the end of the assembly operation.

• on tend un treillis entre deux zones de tension et ce, en exerçant une traction au long de certains des fils de chaînes,
• on positionne des moyens de liaison en forme de cavalier en certains points du treillis pour délimiter des mailles,
• on aligne les moyens de liaison,
• on insère, par glissement, une barre dite de pression dans la tête des cavaliers,
• on positionne des barres de pression en appui sur des plans d'appui des cavaliers,
• on bascule les dites barres d'appui vers l'axe médian des cavaliers pour venir avec les cavaliers et la barre de pression former des pinces et
• on constitue la paroi filtrante en continu et progressivement et on découpe ensuite la dite paroi aux dimensions souhaitées.

According to the method of manufacturing a filter wall:

• a lattice is tensioned between two tension zones and this, by pulling along some of the warp threads,
• positioning jumper-shaped connection means at certain points of the trellis to delimit meshes,
• the connecting means are aligned,
• we insert, by sliding, a bar called pressure in the heads of the riders,
• pressure bars are positioned on support planes of the riders,
• we tilt the said support bars to the median axis of the riders to come with the riders and the pressure bar to form clamps and
• the filtering wall is formed continuously and progressively and then the said wall is cut to the desired dimensions.

The filtering wall is then coupled to a supporting structure to form a lost formwork.

Claims (21)

1. Filtering wall for a lost frame, including lattice work (2) formed by assembling flexible chain wires (2A, 2B) and flexible woven wires (2C); this lattice work is in turn placed on a structure that cannot be distorted.
   This wall is CHARACTERISED by:

   - on the one hand, certain (2A) chain wires (2A, 2B) are more robust than other chain wires (2B), with the tension on the lattice work (2) thus being generated solely by traction on these more robust chain wires (2A) and

   - on the other hand, it includes tension maintenance averages (3, 4, 5) linking the stronger wires to the structure that cannot be distorted. These tension maintenance averages (3, 4, 5) indicate a larger mesh than the one created by the initial crossing of the chain and woven wires (2C).
2. Filtering wall for a lost frame as per demand 1, characterised by the fact that the tension maintenance averages (3, 4, 5), including:

   - on one side of the lattice work, so-called pressure bars (4) distributed along one of the lattice work's axes.

   - on the other side of the lattice work, so-called support bars (5) distributed perpendicularly to the pressure bars, and

   - at the corners of the meshes, a type of connector (3) linking the bars to one and other, in particular, creating bindings at these connection points, thus holding the lattice work together.
3. Filtering wall for a lost frame as per demand 2, characterised by the fact that the pressure bar (4) is triangular in shape and the outer side of the base is corrugated (4A).
4. Filtering wall for a lost frame as per demand 3, characterised by the fact that the pressure bar includes an axis cavity (4B) to increase flexibility.
5. Filtering wall for a lost frame as per demand 2, characterised by the fact that the connector is in the shape of a wishbone with two legs (3A) with an abutment for the pressure bar and, on the outside, on each of the outside faces of the legs, a support (3C) for the support bars.
6. Filtering wall for a lost frame as per demand 5, characterised by the fact that there is a bolt (3D) that prevents the support bars from sliding sideways.
7. Filtering wall for a lost frame as per demand 1, characterised by the fact that a bolt (3D) consisting of a boss next to one of the supports (3C).
8. Filtering wall for a lost frame as per demand 5, characterised by the fact that the ends of the wishbone's legs feature side notches (3E) to anchor against a "Thor" iron on the structure bearing the frame.
9. Means of production of the filtering wall for a lost frame as per any of demands 1 to 8, characterised by the fact that they include:

   - lattice work (2) rolled on an axis (20) serving as a supply source,

   - between this source 20 and an irreversible advance device, step by step 41, an upstream start-up unit,

   - a unit (40) to introduce the structure that cannot be deformed,

   - a downstream power unit, and,

   - a cut-off post (50) at the appropriate distance downstream from the assembly posts on the filtering wall.
10. Means, as per demand 9, characterised by the fact that they include:

    - a roller (32) and a roller-cuter (32), each fitted with slits (33) designed to allow the wishbone to pass through,

    - a unit composed of two fixed rollers (34, 35) between which a roller (36) is located and is able to move between two positions, one at the top to activate the mandrel, on which the lattice work is wound, and the other at the bottom to stop it.
11. Means, as per demand 10, characterised by the fact that the outside faces of the roller (31) and counter-roller (32) is made from an elastic, flexible material so as to be in sufficient contact with the lattice work.
12. Means, as per demand 10, characterised by the fact that the traction exercised on the lattice work comes either from the mere weight of the mobile roller (36), or this weight is complimented by springs or other means of generating traction.
13. Means, as per demand 9, characterised by the fact that:

    - they include wheels (42) distributed along the transversal axis in the direction of the movement of the lattice work,

    - there are as many wheels (42) as transversally placed wishbones,

    - each wheel (42), whose circumference is a multiple of the meshes' links include regular notches (43) suitable to hold each connector.

    - The interdependent wheels rotate in an irreversible link by link motion.
14. Means, as per demand 13, characterised by the fact that, side-on to these wheels (42) and on the level of the notches (43), the device includes guides (44) for the pressure bars inserted into the heads of the wishbones (3).
15. Means, as per demand 8, characterised by the fact that they include a device (46) to align all of the wishbones (3) located on the axis.
16. Means, as per demand 15, characterised by the fact that the alignment device includes an axis (47) to which pairs of split discs are attached (48). Each disc is designed to slot sideways into a wishbone, and the part of the axis located between the two discs in a pair, to partially lock between the wishbone's two legs.
17. Means, as per demand 9, characterised by the fact that they include a mechanic means (80) that make the support bars swing towards the connector (3).
18. Means, as per demand 17, characterised by the fact that they include a pincer (80) the two jaws of which close together.
19. Production procedure for a filtering wall as per any of the demands 1 to 8, characterised by the fact that the:

    - lattice work is hung between two areas of tension, applying traction along specific chain wires,

    - means of connection are placed in the shape of wishbones on certain points on the lattice work to define meshes,

    - the means of connection are aligned,

    - a so-called pressure bar is inserted into the heads of the wishbones,

    - pressure bars are placed against the wishbones on supports,

    - said bars are swung towards the wishbones' central axis in order to form pincers with the wishbones and the pressure bar.
20. Production procedure for a filtering wall as per demand 1, characterised by the fact that the filtering wall is continuous and progressive and then cuts the aforementioned wall to the desired dimensions.
21. Frame equipped with a filtering wall as per any of the demands 1 to 8.

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