EP0258158B1 - Opening system of a mounting box for reinforcing members connecting two buildings parts, and box provided with such a system - Google Patents

Abstract

This system consists in providing at least one line of weakening (16) extending longitudinally over the face (15) of this box (25) and intended to be placed on the side of the first building part. Each line of weakening (16) can be formed by a reduction in the thickness of the material of the face (15) of the box (25), or by a succession of small aligned holes. Upon extraction of the box (25), this or these line(s) of weakening (16) cause(s), when traction is exerted on the accessible part of the box (25), the bottom of this box (25) to rupture along this or these line(s) of weakening (16), and the box (25) can then be extracted in one piece whatever its shape. <IMAGE>

Description

The present invention relates to a box for placing on waiting frames for connection between two contiguous concrete parts of the structure and poured one after the other.

This holding is generally carried out by completely coating the part of the frames intended to be placed in the second part of the structure, this coating being produced, either by embedding these parts of the frames in a brittle material such as synthetic foam, which is then scraped off, either by placing these same parts of the reinforcements in boxes in one or more parts (cf. EP-0 055 321 and DE-32 22 375).

De-32 22 375, in the name of DOLLEN, relates in particular to a box for the waiting of reinforcements which is produced in a single part.

As shown in Figure 1, which is a perspective view of a box 1 of this type, it is formed of a hollow section provided with a longitudinal opening 2 on its face 3, or bottom, intended for be placed on the side of the first part of the structure, notches 4 being provided along this opening for the passage of the free parts of the frames housed inside the box.

In this box, the edges 5.6 of the opening 2 have complementary shapes (groove and rib), so as to close the box after introduction of the reinforcements and to prevent the concrete from flowing inside thereof. .

After pouring the concrete, a special tool, which engages the edges 7 of this box, must be used to extract the box in a single part, this one, opening at the place of its opening 2.

This requires that the closure provided by the edges 5,6 of the box is not too resistant, which can lead to an untimely opening of the latter during handling or during pouring of the concrete.

Figure 2 shows, in cross section, another box 10 of the type known under the trade name "BREFER" and which consists of a bottom 11 having the shape of a U-shaped profile and a cover 12, both made of plastic. The cover 12 is welded to the bottom 11 after introduction of the reinforcements.

After pouring the concrete, the cover 12 must first be detached from the bottom 11, which requires that the weld between the bottom 11 and the cover not be too strong; then the bottom must be removed, after unfolding the frames, in another operation.

These different boxes are therefore not entirely satisfactory, particularly with regard to their removal, which often poses difficulties because they open more or less easily.

Figure 8 shows in a perspective view yet another type of box 30 known under the trade name "COMAX" and which consists of a metal bottom 31 formed of a profile having a cross section in the shape of omega and a cover 32 formed by a plastic band, the edges 32a of which are folded in order to hang behind the flanges 33a of the wings 31a from the bottom 31 in order to ensure the closing thereof.

This cover 32 further comprises two lines of small perforations 34 in the vicinity of its edges in order to allow the opening of the box by tearing the cover along these lines 34, once the first part of the work is finished; the bottom 31 and the edges 32a of the cover being abandoned in the concrete.

In the case which is represented in FIG. 9, and which commonly occurs, where one of the edges 31a of the box 30 is located in the immediate vicinity of an outer face 35 of the concrete structure, the area 36 of the part of the work between the formwork 37 and the edges 31a of the bottom 31 of the box does not fill properly with concrete due to its small thickness, and this both when concreting the first part of the work and when concreting of the second part of the structure.

This leads on the one hand to aesthetic defects of the external face 35 of the concrete work part and on the other hand to a risk of corrosion of the metal base 31 which, not being completely coated with the concrete, is poorly protected .

The object of the present invention is to remedy these drawbacks and to provide a box which can be easily removed once the concrete has been poured, and in particular to provide an opening system which can be adapted to any type of box.

This object is achieved by a box according to claim 1.

During the extraction of the box, the weakening line causes, when a traction is exerted on the accessible part of it, the rupture of the bottom of the box, which is retained by the folded parts of the reinforcements, along the weakening line, and the box can then be extracted in one piece regardless of its shape.

This system can also be used for a box designed in two parts (bottom and cover) welded or glued, or in one piece with closure by complementary profiled edges or glued or welded, and is therefore particularly advantageous.

In all cases, this system avoids the difficulty of designing the closure of the box so that it can then reopen when desired while being strong enough not to open unexpectedly, for example during handling and pouring concrete.

Advantageously, this weakening line can be constituted by a localized reduction in the thickness of the material constituting the box.

It can also be constituted by a succession of small aligned holes, as well as by tearing primers from the openings for passage of the frames, these different embodiments being able to be combined as desired between them.

• Figure 3 est, à échelle agrandie, une vue de détail d'un exemple d'affaiblissement d'un caisson :
• Figure 4 est une vue similaire à figure 3 montrant un autre exemple d'affaiblissement d'un caisson ;
• Figures 5, 6 et 7 sont des vues en perspective montrant différents caissons équipés du système d'ouverture selon l'invention.
• Figure 10 est une vue en coupe transversale d'un caisson selon une autre forme de réalisation de l'invention,
• Figure 11 est, à échelle agrandie, une vue de détail du caisson de figure 10,
• Figure 12 et 13 sont des vues similaires respectivement à figures 10 et 11 d'un caisson selon encore une autre forme de réalisation de l'invention.

In any case, the invention will be better understood and other characteristics will be highlighted with the aid of the description which follows with reference to the appended schematic drawing illustrating by way of nonlimiting examples several embodiments of the system. opening according to the invention:

• Figure 3 is, on an enlarged scale, a detailed view of an example of weakening of a box:
• Figure 4 is a view similar to Figure 3 showing another example of weakening of a box;
• Figures 5, 6 and 7 are perspective views showing different boxes equipped with the opening system according to the invention.
• FIG. 10 is a cross-sectional view of a box according to another embodiment of the invention,
• FIG. 11 is, on an enlarged scale, a detailed view of the box of FIG. 10,
• Figure 12 and 13 are views similar to Figures 10 and 11 respectively of a box according to yet another embodiment of the invention.

As shown in Figure 3, the opening system according to the invention is formed by a weakening of the material in the bottom 15 of a box, that is to say in the face thereof is intended to be placed on the side of the first part of the work, this weakening being here constituted by a decrease 16 in the thickness of the material constituting this bottom 15, along a line extending over the entire length of the box. In this example, the weakening line 16 extends along the openings 18 formed in the bottom 15 of the box for the passage of the frames.

Such a reduction in thickness can be achieved very easily, since the boxes are generally formed from plastic materials.

Slots 17 are also provided along the line of weakness 16 on either side of each opening 18.

These slots 17 constitute fracture initiators and facilitate the opening of the box by rupture of the material constituting it along its line of weakness 16.

In the example shown in Figure 4, the weakening of the material is constituted by a series of small spaced holes 20 arranged along a line 21 which also extends over the entire length of the bottom 15 of the box.

As before, this line of holes 20 extends along the openings 18 intended for the passage of the frames.

It will be readily understood that this series of holes 20, like the thickness reduction line 16, facilitates the opening of the bottom 15 of the box by breaking along the weakening line thus formed.

FIGS. 5 to 7 show different examples of application of the system according to the invention to wells of known type, which will be designated overall by the same reference 25 in each of these figures, and in which the same elements will be designated by the same references.

In the example shown in FIG. 5, the box 25 comprises a series of small aligned holes 20, represented only by dotted lines in this figure, extending over the entire length of this box.

The line 21 of holes 20 extends along the openings 18 provided for the passage of the reinforcements, and the incipient fractures formed by slots 17 are provided on each side of the openings 18.

In the example of FIG. 6, the box 25 has two series of parallel openings 18 for the passage of the frames and is therefore intended in particular for frames with two strands. In this case, the weakening line 16 (which is shown in dotted lines in this figure) is formed by a reduction in the thickness of material, and extends between the two series of passage openings 18.

The fracture initiators can then be constituted by slots 19 extending transversely to the longitudinal direction of the box and connecting together two openings 18 located on parallel lines.

Slots 17 extending along the line of weakness 16 can also be provided, at the junction of the latter and the slots 19, to constitute yet other incipient fractures.

In the example shown in FIG. 7, the box 25 also comprises two series of parallel openings 18, but in this case, two collapsing lines 21 constituted by a series of holes 20 are provided, each line of decay extending along a series of openings 18.

In this case, the longitudinal slots 17, on either side of each opening 18 are sufficient to constitute incipient fractures.

In the exemplary embodiment shown in FIGS. 10 and 11, the box 40 comprises a bottom 41 constituted by a simple metal plate and a cover 42 constituted by an open plastic section having in cross section a trapezoidal shape.

This cover 42 can also be made of plastic by thermoforming or any other means.

The end of each of the wings of the cover 42 has a return 43 extending longitudinally and capable of being placed on each of the edges of the bottom 1 to ensure the closure of the assembly.

As shown more particularly in FIG. 11, at the junction between each return 43 and the wing 42a of the corresponding profile is made a weakening line 45 constituted in this case by a thinning of the wall of the profile but which can be also consisting of a line of small perforations as explained above.

The opening of the box 40, once the first part of the work is completed, is then carried out, at the bottom 41 of the latter, by tearing the cover 42 along the weakening lines 45. Only the bottom 41 remains therefore embedded in the concrete part of the work.

Therefore, any risk of corrosion of the metal bottom 40, as in the case of the so-called "COMAX" box, is therefore ruled out since the wings 42a of the cover are removed with the whole of it and therefore do not interfere with the pouring of the second anchoring part, and the concreting no longer has a defective area.

FIGS. 12 and 13 show another type of box 50 similar to box 40 and comprising, like the latter, a bottom 51 formed by a simple metal plate and a cover 52 constituted by a profile or the like made of plastic material, both, at the end of each of its wings, a return 53 delimiting a groove capable of being placed on each of the edges of the bottom 51 to ensure the connection of the latter to the cover 52.

The only difference between these two boxes is the shape of the cover 52, which has, in cross section, essentially the shape of a U with two "skirts" 54 side, each skirt going away from the edge of each wing 52a to beyond the bottom of the cover 52.

In this case also, a weakening line 55 is made at the bottom 51 of the box 50 and more precisely in the junction area of the returns 53 and the wings 52a, in order to allow the opening of the box by tearing the cover 52 at the bottom 51 of the box.

Of course, the various weakening means described above can be combined with one another, for example a line of material of lesser thickness can be combined with a line of holes.

Claims (6)

1. A box for the placing in readiness of reinforcements for connecting two concrete building parts, characterised in that it includes at least one weakening line (16, 21, 45, 55) which extends longitudinally over the face of the box intended to be located on the side of the first building part and connects together a series of openings (18) through which the reinforcements pass or a series of slots (19) communicating with these openings.

2. A box according to Claim 1, characterised in that each weakening line (16) is constituted by a decrease in the thickness of the material of the face (15) of the box.

3. A box according to Claim 1, characterised in that each weakening line (21) is constituted by a succession of small holes (20) aligned and arranged as a broken line.

4. A box according to any one of Claims 1 to 3, characterised in that, when it comprises at least two series of aligned openings (18) through which the reinforcements pass, each weakening line (16, 21) connects together the holes (18) of a series and slots (17) constituting rupture starts are provided on each weakening line (16, 21) to either side of each opening (18).

5. A box according to Claim 4, characterised in that a slot (19), constituting a rupture start and extending transversely of the box, connects two openings (18) of two separate series of openings.

6. A box according to Claim 5, characterised in that a slot (17) constituting a rupture start is also provided along the weakening line (16, 21) in the region of the junction of the latter with the slot (19).

Images