EP0001723B1 - Prefabricated structural element used as a form - Google Patents

Description

The present invention relates to a prefabricated construction part forming a lost formwork element and comprising several first unitary elements of construction material assembled end to end, in particular for the manufacture of a lintel, of a framework post, an opening frame, etc ...

Most of these construction parts are generally manufactured on site, which requires the creation of formwork, shoring, concrete pouring, dismantling of formwork, the possible installation of insulation ...

It has indeed been proposed in GB-A-114 253 to produce prefabricated beams by assembling bricks end to end on a bed of mortar resting on a row of tiles. This certainly gives a prefabricated beam, but its working is not easy and the installation of insulation must be carried out on site.

It has also been proposed to produce construction elements, and more precisely prefabricated blocks with incorporated insulation. Such elements with bearing part and counter-partition situated on either side of an insulating plate which ensures their mechanical connection are described in FR-A-2341 714. However, this does not solve the problem of manufacturing lintels, posts, frames and other parts of the building located at singular points, especially if we want to achieve continuity at these points.

Also, the invention aims to achieve a prefabricated construction part forming a lost formwork element, which can be manufactured to the dimensions required in the workshop or factory, so that it can be mounted directly without requiring handling equipment and limiting the minimum site operations.

This object is achieved by a construction part in which, in accordance with the invention, the first unitary elements are secured at least on one of their faces by a plate of thermally insulating material which is mechanically connected to each of them by a tenon and mortise type bonding which is made of a material selected from the group consisting of polyurethane foams and phenolic foams.

Thus, a construction part of a given length or height is formed by assembling end to end the necessary number of unit elements which are joined together by the plate of insulating material, which allows the transport of the part on the site. .

One can provide, on the side of the insulating plate opposite to that connected to the unitary elements, a row of second unitary elements forming a counter-partition when the construction part is mounted. Therefore, we obtain a construction part comprising, on the one hand, the first unitary elements to form a formwork for a lintel, a post, a frame, a support, ... and, on the other hand, second unitary elements which form against-partition, a plate of insulating material being interposed between the first and second unitary elements to ensure both their connection and the function of thermal insulation without bridge.

A particular advantage of construction parts according to the invention lies in the fact that they make it possible to meet the standards in force relating to the cracking of coatings. Indeed, these parts intended for the singular points of a building can have thermal insulation characteristics comparable to those of building blocks as described in FR-A-2 341 714 already cited. In particular, it will be possible to form cells in the unitary elements constituting these parts. This avoids, at singular points, the formation of thermal bridges with temperature gradients likely to cause cracking of the coatings.

The first unitary elements are made of a construction material chosen from concrete, terracotta, building stones, etc. The second unitary elements, when they are provided, can also be made, at least in part, in one of these materials. These second elements forming against-partitions can of course be made of other materials, for example based on plaster. They can even be multilayer elements.

The mechanical connection between the insulating material plate and the unitary elements placed end to end is of the tenon and mortise type. This term covers a connection with for example at least one rib or groove of the plate engaged in a groove or rib of corresponding shape formed by the alignment of grooves or ribs of the different elements. These ribs or grooves can be continuous or discontinuous.

The connection can also be achieved by engagement of pins carried by the plate in blind holes of the unit elements.

The connection is preferably of the built-in type, that is to say with ribs or nipples having an increasing section from the surface of the plate on which they project. However, if the end use of the construction parts allows, the connection may not be built-in.

For the manufacture of a construction part in accordance with the invention, the number of unitary formwork elements necessary to obtain a part of a given length is placed in a row and these elements are secured by positioning, for example by expansion in place, of a polyurethane foam or of a phenolic foam. In the preferred case of a building part with a row of first and a row of second unit elements, the expansion of the insulating foam is carried out in a interval between these two rows.

• - la figure 1 est une vue partielle en perspective d'une pièce conforme à l'invention formant coffrage perdu pour un linteau,
• - la figure 2 est une vue partielle en perspective d'une pièce conforme à l'invention formant coffrage perdu pour un poteau d'ossature,
• - les figures 3 et 4 sont deux vues de pièces conformes à l'invention pour un encadrement de fenêtre ; et
• - la figure 5 est une vue partielle en perspective d'une pièce conforme à l'invention pour un appui de baie.

Other particularities and advantages of the construction parts in accordance with the invention will emerge on reading the description given below, with reference to the accompanying drawings, of which:

• FIG. 1 is a partial perspective view of a part according to the invention forming lost formwork for a lintel,
• FIG. 2 is a partial perspective view of a part in accordance with the invention forming a lost formwork for a frame post,
• - Figures 3 and 4 are two views of parts according to the invention for a window frame; and
• - Figure 5 is a partial perspective view of a part according to the invention for a bay support.

Figure 1 shows the first unitary formwork elements 10 identical to U-shaped assembled end to end and mechanically secured by a plate 11 of expanded insulating material. ¹

The plate 11 carries, on its face 11a facing the first elements 10, ribs 12 in dovetail. Each rib 12 is housed in a groove which is formed by putting end-to-end grooves 13 present on the outer faces of the wings 10a of the first elements 10 adjacent to the plate 11.

The second unitary counter-partition elements 15 in the form of plates of the same length I as the first elements 10 are assembled end to end and mechanically secured by the plate 11 on the side of its face 11b opposite the face 11a. On this face 11b, the plate 11 carries ribs 16 in dovetail. Each rib 16 is housed in a groove formed by the end to end grooves 17 of the faces 15a of the second elements 15.

The elements 10 secured by the plate 11 form a construction part 18 which can constitute, for example, a formwork for a lintel. The part 18 is put in place and then concrete is poured inside the first elements 10. Of course, the part 18, forming lost formwork, is left in place after the concrete has hardened and a lintel is obtained with a counter partition and an insulating plate incorporated without thermal bridges between the counter-partition and the lintel.

Note that the mechanical connection made by the plate 11 must give the part 18 sufficient mechanical strength to form a lost formwork allowing, without further reinforcement, the pouring of concrete. Also, the insulator used is a relatively dense insulator having good mechanical properties, for example a polyurethane foam.

To make the part 18, we proceed for example as follows. The first formwork elements 10 and second counter-partition elements 15 are placed end to end in a necessary number according to the length desired for the part 18. They are arranged in two parallel rows providing an interval between them, the elements 10 and 15 being placed with their faces provided with grooves facing one another. In the interval between these faces, the polyurethane foam expands. The plate 11 is formed with its ribs 12 and 16. We then obtain the connection between the plate 11 and each of the elements 10 and 15. Of course, we can obtain a connection with ribs 12, 16 and grooves 13, 17 in profile other than in a dovetail, for example in a T profile, or, more generally, with a relief of the faces, facing one another, elements 10 and 15 suitable for ensuring a mechanical connection with the material insulating after expansion of the latter.

The first formwork elements 10 and the second counter-partition elements 15 are for example concrete elements produced by molding in installations of known type for the manufacture of blocks. Other materials could be used for these elements, for example shaped terracotta or a cut building stone. In addition, the counter-partition element 15 may be a multilayer element and in particular comprise a fire-resistant layer, for example of plaster.

Figures 2 to 5 illustrate other embodiments of construction parts according to the invention. The constituent materials of the elements forming these parts as well as their methods of manufacture and assembly are similar to those described above for part 18 and will therefore not be described below in detail.

FIG. 2 shows a part 28 comprising a row of first unit elements 20 in the form of frames assembled end to end and mechanically fastened on one of their faces by an insulating plate 21, the plate 21 bearing on its face 21 turned towards the first elements 20 one or more ribs 22 engaged in grooves 23 of the elements 20. On its other face 21 b, the plate 21 carries ribs 26 engaged in grooves 27 of second elements 25 in the form of plates placed end to end and constituting a counter partition. Cavities 24 are formed in parts of the elements 20 not adjacent to the plate 21.

The elements 20 form formwork elements which, when assembled, constitute a formwork for the casting of a stud. To this end, irons 29 can be placed inside the formwork when the part 28 is prefabricated.

FIGS. 3 and 4 show a part 38 with first unit elements 30 in the form of frames placed end to end and mechanically assembled by an insulating plate 31. Second unit elements 35 placed end to end are also mechanically assembled by plate 31, on the side opposite that on which the elements 30 are located, and form a counter-partition. Alveoli 34 are formed in parts of the elements 30 not adjacent to the plate 31.

The part 38 constitutes a part framing a door or window, for example a part to be placed vertically against the end a wall 39. The latter is for example made up of prefabricated blocks 40 with an external bearing part 41 and an internal counter-partition 42 assembled by an intermediate insulating plate 43. Such blocks are described in particular in FR-A-2 341,714.

Once the framing element 38 has been placed, concrete can be poured inside the lost formwork constituted by the frames 30.

Note that a longitudinal groove 44 may be formed on the outer face of the side of the elements 30 facing the blocks 40. Similarly, the bearing parts 41 of these blocks may have a longitudinal groove 45 facing the groove 44 for form with the latter a cell 46 after final establishment of the part 38.

The part 38, with its cells 34 and, possibly, the cell 46, makes it possible to perfectly satisfy the standards relating to the cracking of coatings. Indeed, although placed at a singular point of the building, this room 38 is not unique, from the point of view of thermal insulation, with respect to blocks 40. There is then no reason to fear the appearance of thermal bridges at the place occupied by the part 38. This remark made for the framing part 38 applies of course also for the other parts according to the invention placed at singular points.

The part 38 carries sealing tabs for fixing the hinges 47 for the shutter. The plate 31 and the counter-partition 35 are of width less than that of the frames 30 for mounting the frame 48 and the window 49. The embodiments illustrated in FIGS. 3 and 4 differ in that, in the case of FIG. 3, it is a frame for a splayed window, while, in the case of FIG. 4, it it is an interior bare window.

FIG. 5 illustrates yet another embodiment of a part 58 according to the invention. This piece constitutes a window sill and comprises first identical unit elements 50 assembled end to end which form the support itself. These first elements 50 are secured by an insulating plate 51, as well as second unit elements 55 forming against-partition. Longitudinal cells 54 pass through each first element 50.

As can be seen in FIG. 5, the plate 51 has a thickness greater in its lower part than that which it presents in its upper part and thus has a shape adapted to that of the part 58. In addition, this results in a relief of the first unitary elements 50.

Irons 53 intended to be embedded in concrete can be placed in a longitudinal groove 56 formed by the end-to-end assembly of the grooves 52 provided in the upper face of the first elements 50.

Of course, other embodiments of parts in accordance with the invention could be envisaged.

The length of the unitary elements constituting the parts in accordance with the intention is chosen, for example of the order of one or more tens of centimeters, to allow, by assembling a certain number of these elements, to cover the majority of the requirements as to the lengths of the parts to be prefabricated in the factory or workshop before their transport to the site. It will also be noted that it is possible to envisage the arrangement of insulating plates on several of the faces of a row of unitary elements such as for example the rows of elements 10 and 20 of formwork.

Of course, other modifications or additions may be made to the embodiments described above of parts in accordance with the invention without, however, departing from the protective framework defined by the content of the appended claims. Thus, although it has been envisaged in the foregoing the case where the plate of insulating material is produced by expansion in place of a plastic foam, the joining of the unitary elements could also be carried out by inserting a plate previously molded.

Claims (8)

1. Prefabricated construction piece forming sacrifice shuttering and comprising a plurality of first unitary elements made of construction material assembled end to end, characterized in that the first unitary elements (10, 20, 30, 50) are connected at least on one of their faces by a plate (11, 21, 31, 51) of heat-insulating material which is mechanically connected to each of them by a tenon and mortise type connection and which is made of a material chosen from the group constituted by polyurethane foams and phenolic foams.

2. Construction piece according to Claim 1, characterized in that it comprises second unitary elements (15, 25, 35, 55) similar to one another, assembled end to end and connected, on one of their faces, by the plate (11, 21, 31, 51) of insulating material, the first and second elements being placed on each side of the plate and the second elements constituting a counter-partition.

3. Construction piece according to either of Claims 1 and 2, characterized in that the first unitary elements (10, 20, 30, 50) are made of a material chosen from the group including concrete, terra cotta and construction stones.

4. Construction piece according to any one of Claims 1 to 3, characterized in that the first elements are U-shaped shuttering elements (10) particularly for lintel.

5. Construction piece according to any one of Claims to 3, characterized in that the first elements are shuttering elements (20) in the form of frames, particularly for post.

6. Construction piece according to any one of Claims 1 to 3, characterized in that it constitutes a door or window frame piece (30).

7. Construction piece according to any one of Claims 1 to 3, characterized in that it constitutes a support piece (50) for window or bay.

8. Construction piece according to any one of Claims 5, 6 and 7, characterized in that the first unitary elements (30, 50) present cells (34, 54) at least in their parts other than those adjacent the plate (31, 51) of insulating material.

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