EP1039038B1 - Form removal apparatus aid - Google Patents

Description

The subject of the present invention is a device for assisting formwork removal for wall panel end joint molded.

When one wants to make a diaphragm wall, that is to say a wall made of concrete in a trench dug in the ground, one perform this operation in successive tranches, each corresponding to to a molded wall panel, all the panels constituting the wall.

To ensure the mechanical continuity of the panels of the wall in the connection zone between two panels, we give the end of each panel a particular shape called joint, which allows embedding one end of a panel in the end of the previous panel. The definition of this form corresponding to the joints is achieved through the placement, at the end of the trench into digging course, a form whose shape allows to obtain the seal of the panel in progress.

Referring firstly to the appended figures 1a and 1b, will describe the known technique of realization of the different panels of a molded wall. At first, we dig a first trench portion 10 corresponding to a first panel and is placed an end seal formwork 12 at the end 10a of the portion of trench. In known manner, the formwork 12 comprises a sole 14 and a box 16 defining the shape of the seal and, preferably, that structure 18 allowing the holding and the protection of an element of connection 20 between sealing elements that can be provided in the molded wall.

As shown in Figure 1a, the concrete constituting the panel 22 bypasses the ends of the sole 14 of the formwork 12 in the lateral zones referenced 24. Part of this concrete may even end up against the outer face 14a of the sole 14 as this is shown in 26.

In the next step illustrated in FIG. 1b, the digging a second portion of trench 28 intended to constitute the following molded wall panel. When digging with the bucket, it is possible to scrape the outer wall 14a of the sole 14 to remove the corresponding concrete portion. However, the experience shows that there are still concrete zones of bypass referenced 24.

Before filling the second trench portion 28 with concrete, it is of course necessary to extract the formwork 12. This operation is difficult because of the adhesion between the concrete and the inner face 14b of the footing 14 of the formwork, as well as with the casing 18. In addition, this operation is even more delicate because of the presence of concrete circumvention in zones 24.

To solve this problem, it has already been proposed in the patent French 2,613,395 to coat the face of the formwork facing the concrete of a thin material likely to be abandoned in the trench for avoid adherence of the concrete to the formwork and extract the formwork substantially vertically.

It has also been proposed to solve this same problem in French Patent 2,647,828 to apply a shock on the seal on the side opposite the concrete using a tool guided by the joint itself.

Another known technique to achieve the stripping of the chest 12 is to use formwork "hands" which consist, as will be explained in more detail later, essentially in two pieces in the form of hooks which are engaged at the ends of the sole of the formwork and whose active parts are engaged on the face internal ends of the sole. FIG. 1c shows the setting up and the general shape of the formwork hands 30 and 32.

Figure 1d shows a stripping hand 30. It comprises a mounting end 31 on a machine, an arm 33 intended to move to side of the side edge of the sole 14 and a return 30a to be inserted between the inner face 14b of the sole and the concrete to take off the concrete formwork.

Due to the presence in zones 24 of the bypass concrete the engagement of the formwork hands 30 and 32 is very difficult. Indeed, these hands have to make their way through the areas of concrete bypass 24 over a width of 2 to 3 cm identified corresponding to the width of the stripping hands and over a length may exceed 5 cm and marked e 'corresponding to the circumvention of the concrete in the zones 24. Such an operation induces on the hands of dismantling of the very important constraints that can lead to their rupture or at least their wear very premature. In addition, jamming phenomena make this delicate operation and therefore long which induces a significant cost in the realization of the wall molded.

An object of the present invention is to provide a device formwork for formwork for a panel end joint molded wall which allows the use of stripping hands in greatly improved conditions to limit the wear of the hands of stripping and increase the speed of the stripping operation.

• deux plaques sensiblement rectangulaires et sensiblement de mêmes dimensions,
• des moyens d'entretoisement solidaires d'un premier bord longitudinal desdites plaques pour maintenir celles-ci sensiblement parallèles entre elles avec un écartement h sensiblement égal à l'épaisseur de la semelle du coffrage,
• des moyens de remplissage pour remplir le volume limité par lesdites plaques, les moyens d'entretoisement et un plan orthogonal auxdites plaques disposé à une distance d des deuxièmes bords longitudinaux des plaques, par quoi l'espace entre lesdites plaques dépourvu de moyens de remplissage est apte à recevoir une portion latérale de la semelle d'un coffrage, lesdits moyens de remplissage étant réalisés avec un matériau à faible résistance mécanique ; et
• des moyens de fixation temporaire desdites plaques sur ladite semelle.

To achieve this object, according to the invention, the device for assisting the formwork of formwork for a molded wall panel end joint, said formwork comprising a sole having an external face, an internal face equipped with a box and two side edges, said box leaving free on the outer face of the sole two side zones near said edges is characterized in that it comprises

• two substantially rectangular plates and substantially of the same dimensions,
• bracing means secured to a first longitudinal edge of said plates to maintain them substantially parallel to each other with a spacing h substantially equal to the thickness of the sole of the formwork,
• filling means for filling the volume limited by said plates, the bracing means and a plane orthogonal to said plates disposed at a distance d from the second longitudinal edges of the plates, whereby the space between said plates devoid of filling means is adapted to receive a lateral portion of the sole of a formwork, said filling means being made of a material of low mechanical strength; and
• means for temporarily fixing said plates on said sole.

We understand that thanks to this provision, the hands of stripping will be engaged vertically on both sides of the outsole at the portions of the stripping assist devices constituted at least in part by the filling means of which the mechanical strength is relatively low. So we can get the penetration of the stripping hands in areas where there is no bypass concrete and constituted at least in part by the material filling with low mechanical resistance.

In addition, the very presence of assistive devices Stripping limits the areas occupied by the bypass concrete.

According to a first embodiment, the device is characterized in that said plates and said bracing means consist of a stamped metal sheet consisting of two wings and a connecting portion, in that said means for filling are constituted by a parallelepipedal part arranged between the wings of the sheet against the connecting portion, said means filling material being made of a non-plastic material to be impregnated with concrete.

According to a second embodiment of the invention, the device is characterized in that said wooden plates, said means of bracing consist of a wooden cleat fixed between said plates along their first longitudinal edge and in that the filling means are constituted by a parallelepiped piece arranged between said plates against said cleat, said piece being made of a plastic material which can not be impregnated with concrete.

According to a third embodiment, the device characterized in that said wooden plates, said means bracing consists of elements of wooden battens fixed between said plates along their first longitudinal edge, said cleat elements leaving between them free spaces according to the direction of the longitudinal edge of said plates and in that the means filling elements are constituted by parts substantially parallelepipeds in a plastic material not likely to be impregnated with concrete, said pieces being arranged in the spaces separating the elements of the cleat.

According to a preferred embodiment, the means of filling are made of polystyrene. This material presents the advantage of having a low mechanical resistance compared to the hands of formwork while preventing the concrete filling of the area disposed between the two plates forming the disassembly aid device.

les figures 1a à 1c, déjà décrites, illustrent un procédé de réalisation de panneau de paroi moulée selon l'état de la technique ;

la figure 1d, déjà décrite, montre une main de décoffrage de type connu ;

la figure 2 est une vue en coupe horizontale montrant le principe de réalisation des dispositifs d'aide au décoffrage ;

les figures 3a à 3c montrent le mode d'action des mains de décoffrage sur un coffrage équipé des dispositifs d'aide au décoffrage ;

la figure 4a montre un premier mode de réalisation du dispositif d'aide au décoffrage ;

la figure 4b montre la mise en place du dispositif d'aide au décoffrage de la figure 4a sur un coffrage ;

la figure 5a montre en perspective un deuxième mode de réalisation du dispositif d'aide au décoffrage ;

la figure 5b montre la mise en place du dispositif d'aide au décoffrage de la figure 5a sur un coffrage ;

la figure 6a montre en perspective un troisième mode de réalisation du dispositif d'aide au décoffrage ;

la figure 6b montre la disposition du dispositif d'aide au décoffrage de la figure 6a selon sa direction verticale ;

les figures 7 et 8 montrent en perspective deux moyens préférés de fixation d'un dispositif d'aide au décoffrage sur la semelle d'un coffrage.

Other features and advantages of the invention will appear better on reading the following description of several embodiments of the invention given by way of non-limiting example. The description refers to the appended figures in which:

Figures 1a to 1c, already described, illustrate a method of producing molded wall panel according to the state of the art;

Figure 1d, already described, shows a formwork of known type;

Figure 2 is a horizontal sectional view showing the principle of embodiment of the formwork removal devices;

FIGS. 3a to 3c show the mode of action of the stripping hands on a formwork equipped with stripping assistance devices;

Figure 4a shows a first embodiment of the formwork removal device;

Figure 4b shows the establishment of the formwork assist device of Figure 4a on a formwork;

FIG. 5a shows in perspective a second embodiment of the formwork assistance device;

Figure 5b shows the establishment of the formwork removal device of Figure 5a on a formwork;

FIG. 6a shows in perspective a third embodiment of the formwork removal device;

Figure 6b shows the arrangement of the formwork assist device of Figure 6a in its vertical direction;

Figures 7 and 8 show in perspective two preferred means of fixing a formwork removal device on the sole of a formwork.

Referring first to Figure 2, we will describe the principle of the formwork removal device. In this figure, we have represented the formwork 12 with its sole 14 the formwork being put in place in the trench 10 in which the wall panel 22 has already been realized. The invention consists in fixing on each edge 34, 36 of the sole 14 a structure with the general reference 40 later on. called stripping assistance device. This structure 40 that overflows so on each side of the sole 14 inside the trench 16 is constituted by a set of materials that vis-à-vis the hands of formwork has a reduced mechanical strength and which, by its presence, limits the constitution of bypass concrete in the area corresponding. This structure will be described later in more detail with reference to Figures 4 to 6.

Referring now to Figures 3a to 3c, we will describe briefly the mode of use of devices 40 stripping. Before the introduction of the formwork 12 in the trench, fixed at the ends 34 and 36 of the sole 14 a device 40 for assisting the formwork and the formwork thus equipped is set up in the trench. After the concrete filling of the first trench portion 10 then digging the second trench portion 28 and scraping the external face of the sole, there are two zones 24 'of concrete of circumvention whose dimensions are smaller than those found in the prior art because of the presence of the devices 40. Furthermore, it is understood that between the zones 24 'comprising the concrete of bypass and the soleplate 14 proper devices 40 constitute two areas of reduced strength compared to that of concrete. It is possible then to present at the top end of formwork the formworking hands 30 and 32 in such a way that their arm 33 are facing the devices 40 and that their active parts 32a, 30a are arranged facing the inner face 14b of the sole. With the help of the machine on which the demounting hands 30 and 32, we can lower these which destroy as and when their depressing the devices 40, the active parts 32a and 30a of the hands of formwork causing progressively the separation of the sole 14 and its box 16 with respect to the concrete 22 filling the portion of trench. When the stripping hands arrive at the bottom of the formwork it is then possible to easily make the extraction.

If we go back to Figure 2, we see of course that if we call L the width of the sole 16 and L1 the width of the trench 10, the formwork removal devices 40 must have such dimensions, after their attachment on the sole, the overall size of these L2 is less than the width L1 of the trench.

Referring now to Figures 4a and 4b will be described a first embodiment of the formwork assistance device. The device 40 is constituted by a stamped sheet 50 which has two substantially parallel and rectangular wings 52 and 54 connected to each other by a connecting portion 55. The length of the sheet is substantially equal to that of the sole of the formwork. The connecting portion 55 forms a bridging between the two plates, the distance h between the two wings 52 and 54 is slightly greater than the thickness of the sole of the formwork. In the volume limited by the two wings 52 and 54 is fixed a substantially rectangular parallelepipedal piece 56 which is applied against the connecting portion 55. This piece 56 is made of a plastic material that can not be impregnated with concrete, such as polystyrene. There remains between the wings 52 and 54 an empty volume 58 of length d inside which is received the lateral portion of the sole when the device 40 is fixed thereon. Preferably, the stamped sheet 50 has a thickness of the order of 4 to 6/10 ^e millimeters. It is understood as best shown in Figure 4b that the area occupied by the part 56 is an area of reduced strength in which can easily enter the stripping hand. It goes without saying that the width f of the part 56 must be greater than the width I of the arms 33 of the stripping hand.

Referring now to Figures 5a and 5b there will be described a second embodiment of the device 40 for the formwork removal. This device consists of two wooden boards 60 and 62 of substantially rectangular shape, the first two edges 60a, 62a are interconnected by a wooden batten 64 acting as a spacer to maintain the two boards 60 and 62 substantially parallel with a spacing h corresponding to the thickness of the flange of the formwork. A piece 66 of substantially rectangular parallelepiped shape is disposed between the boards 60 and 62 and against the batten 64. This piece 66, of width f, is made of a plastic material not likely to be impregnated with the concrete such as polystyrene. There remains thus between the boards 62 and 60 a free space 68 of length d able to receive the lateral edge of the flange 14 of the formwork. As best shown in Figure 5b the volume constituted by the parts 66 preferably polystyrene constitutes on either side of the sole 14 a zone of limited strength in which the stripping hand can easily penetrate.

Figures 6a and 6b illustrate a third embodiment of the device 40 for formwork removal. In this embodiment, the device 40 is further constituted by two wooden planks 70 and 72 which are substantially rectangular and which are interconnected by wooden batten elements such as 74 which thus form spacers for holding between the planks 70 and 72. a gap h . Between the batten elements 74 fixed near the first edge of the boards 70 and 72 are formed spaces such as 76 in which are fixed parts 78 made of a low-strength material such as polystyrene. As best shown in FIG. 6b, there is thus alternating batten elements 74 and parts, for example made of polystyrene, 78 arranged parallel to the first edge of boards 70 and 72. This assembly generally constitutes a zone with reduced mechanical strength of width f which can be penetrated easily by the hands of formwork. The zone 79 which remains empty between the boards 70 and 72 and which has a length d serves to receive a lateral portion of the sole 14 of the formwork.

Figures 7 and 8 show two possible modes of fixation stripping assistance devices 40 on the sole 14.

In the case of Figure 7, the device is fixed by ligatures made using annealed iron wires 80 which pass through holes 82 pierced in the sole 14 near its edge 36.

In the case of FIG. 8, the device 40 is fixed on the edge 36 of the sole 14 using metal stirrups 84 which surround the device 34 and whose ends 86 are welded on the internal faces outer sole 14.

Claims (7)

1. A device (40) for facilitating removal of formwork (12) for the end joint of a panel of a diaphragm wall (22), said formwork comprising a soleplate (14) having an outside face, an inside face carrying a box (16), and two side edges (34, 36), said box leaving two empty side zones (24) on the inside face of the soleplate in the vicinity of said edges, said device being characterised in that it comprises:

   two substantially rectangular plates (52, 54, 60, 62, 70, 72) of substantially the same dimensions,

   spacer means (55, 64, 74) secured to a first longitudinal edge of said plates to hold them substantially parallel to each other at a spacing h that is substantially equal to the thickness of the soleplate of a formwork,

   filler means (56, 66, 78) for filling a volume defined by said plates, by said spacer means, and by a plane orthogonal to said plates at a distance d from said second longitudinal edges of the plates, whereby the space between said plates that does not include said filler means is suitable for receiving said side portions of the soleplate of a formwork, said filler means being made of a low strength material; and

   temporary fixing means (80, 84) for fixing said plates on said soleplate.
2. A device according to claim 1, characterised in that said plates (52, 54) and said spacer means (55) are constituted by a metal sheet (50) shaped to comprise two flanges interconnected by a web, and in that said filler means are constituted by a piece in the form of a rectangular parallelepiped (56) disposed between the flanges of the metal sheet and against the web, said filler means being made of a plastics material that is unsuitable for being impregnated by concrete.
3. A device according to claim 1, characterised in that said plates (60, 62) are made of wood, in that said spacer means are constituted by a wooden batten (64) fixed between said plates along said first longitudinal edges thereof, and in that said filler means are constituted by a piece (66) in the form of a rectangular parallelepiped disposed between said plates and against said batten, said piece being made of a plastics material that is unsuitable for being impregnated by concrete.
4. A device according to claim 1, characterised in that said plates (70, 72) are made of wood, in that said spacer means are constituted by strips of wooden batten (74) fixed between said plates along said first longitudinal edges thereof, said strips of batten leaving empty gaps (76) between one another in the longitudinal direction of the edges of said plates, and in that said filler means are constituted by pieces (78) substantially in the form of rectangular parallelepipeds of a plastics material that is unsuitable for being impregnated by concrete, said pieces being disposed in the gaps between the strips of batten.
5. A device according to any one of claims 1 to 4, characterised in that said filler means (56, 66, 78) are made of polystyrene.
6. A device according to any one of claims 1 to 5, characterised in that said temporary fixing means are constituted by wires (80) surrounding said plates and passing through holes formed through the soleplate of the formwork (14).
7. A device according to any one of claims 1 to 5, characterised in that said temporary fixing means are constituted by metal staples (84) surrounding said plates and having their free ends welded to the inside and outside faces of the soleplate (14) of the formwork.

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