FR2670523A1 - Prefabricated reinforced-concrete wall element - Google Patents

Abstract

The present invention relates to a prefabricated reinforced-concrete wall element equipped with a layer of heat-insulating material and capable of being manufactured flat in a mould. According to one characteristic of the invention, it consists, from the inner face towards the outer face, of a first layer (1) of concrete, the layer (2) of insulating material and a third layer (3) of concrete having a thickness similar to the thickness of the first layer (1). The insulating layer (2) consists of a plurality of panels (2a to 2e) which are continuous via their large sides, a ladder-shaped reinforcement element (6) whose rungs (6a) are in the direction of the thickness of the wall and whose uprights (6b and 6c) are embedded, respectively, in the first layer (1) and in the third layer (3) located in each joining plane (5) between two continuous panels (2i and 2j).

Description

 The present invention relates to a prefabricated reinforced concrete wall element, of the type which is provided with a layer of thermally insulating material, this element being able to be manufactured flat in a mold.

 It also relates to a method of manufacturing such a wall element.

We already know such prefabricated wall elements and reference may be made, for example, to documents FR-A-2 584 437 and
FR-A-2 638 473. According to these documents, a wall element consists, from the internal face towards the external face, of a layer of reinforced concrete which ensures its mechanical resistance, of a layer of insulating material , for example in polystyrene, and a layer which forms the outer covering. This last layer is generally thin compared to that of the wall.

 By its position with one side facing outwards and the other in contact with the insulating layer, it is subjected to relatively high thermal stresses and expansion stresses which can cause it to deteriorate, for example cracking. Given its small thickness, it therefore requires, for its manufacture, materials of high mechanical strength and it is very often reinforced with fibers.

 This particular construction therefore strikes the cost of such a wall and it has therefore been thought, to solve this problem, to produce a wall whose structure is such that it does not require, as external coating, a layer with high mechanical strength but only one layer of the type frequently used in the building such as crepe.

 According to the invention, a prefabricated wall element consists, from the internal face towards the external face, of a first layer of reinforced Breton, a second layer of thermally insulating material and a third layer of reinforced concrete.

 The first and third layers have substantially equal thicknesses and one of them can receive an interior coating such as fabric, paper, etc. and the other a conventional exterior coating, of the crepe type, the latter coating being able to be of low mechanical resistance since it is the third layer which absorbs thermal and expansion stresses.

 Such a structure if it solves the problem mentioned above nevertheless has the following drawback. The wall elements of the invention are transported to the flat site where they are erected to constitute the wall of the building to be constructed. From their passage from the horizontal position to the vertical position, the external layers of the element tend, due to their own weight, to separate from one another and to separate from the insulating layer.

 This drawback has been remedied by the fact that the insulating layer consists of adjoining panels and that each joint between two panels is provided with a ladder-shaped frame, the bars of which are in the transverse direction of the wall and the uprights are parallel to the joint plane, one being embedded in the first layer of reinforced concrete and the other in the third layer of reinforced concrete.

 Thus, by lifting an element according to the invention, the different layers which constitute it remain integral with one another. Furthermore, the ladder frame improves the mechanical strength of this element.

 Note that the fact that the insulating layer is formed of panels does not create thermal bridges between these panels since they are joined. The thermal bridges that may exist are located on the bars of the frame and are generally negligible.

 The assembly of the elements to form a partition must not allow the creation of thermal bridges which would partially lose the benefit of a layer of insulation in the wall elements.

 The invention therefore also relates to assemblies of prefabricated wall elements.

The features of the invention mentioned above, as well as others,. will appear more clearly on reading the following description of an exemplary embodiment, said description being made in relation to the accompanying drawings, among which:
Fig. 1 is a perspective view of a wall element according to the invention, this element being cut along the joint plane between two contiguous panels,
Fig. 2 is a top view of a flat wall element, the third layer of which has been deliberately omitted for the understanding of FIG.,
Fig. 3 is a sectional view along a plane orthogonal to the plane of joint between two adjoining panels, this plane passing through a bar of the frame in scale between these panels, and
Figs. 4a and 4c show in section the arrangements of elements according to the invention with a view to respectively constituting a wall, a corner and an intersection with a cross wall.

 A prefabricated wall element according to the present invention consists, from its internal face towards its external face, of a first layer 1 of concrete, a second layer 2 of thermally insulating material and a third layer 3 of concrete. Each layer 1 and 3 of concrete is reinforced, substantially at an equal distance between its two faces, with a metallic reinforcement 4 in lattice.

 The dimensions of the first, second and third layers are, for example for a wall of 16 cm, respectively 6 cm, 4 cm, 6 cm.

For the production of a load-bearing wall 20 cm thick, the first layer 1, which is arranged to support the floor and the structure of an upper floor of a building, is thicker, for example 8 cm.

 As shown in Fig. 2, the insulating layer 2 consists of panels 2a, 2b, 2c, 2d and 2e rectangular and joined by their long sides. These panels 2i are made, for example, of expanded or extruded polystyrene or of a material of the type of that which is marketed under the brand STYROFOAM. Their width is, for example, 60 cm, their length depends on the height of the wall element and can be 250 cm, and their thickness is between 2 and 6 cm.

 In the joint plane 5 between two panels 2i and 2j, there is provided a frame 6 (Fig. 1) in the form of a ladder whose bars 6a are in the direction of the thickness of the wall element and whose uprights 6b and 6c are one 6b embedded in the first layer 1 of concrete and the other 6c in the third layer 3 of concrete. Each upright 6b or 6c rests on the trellis 4 of the reinforcement of the corresponding concrete layer 1 or 3 and the bars 6a, protruding on each side of the uprights 6b, 6c, go outwards beyond the trellis 4.

 Fig. 3 shows an alternative embodiment in which the panels 2i and 2j have, on their large faces, longitudinal grooves 7, shown here with a dovetail profile but which could also be in rectangular profile. At the joint plane between the two panels 2i and 2j, each of them has a longitudinal rebate 8i or 8j. The two corresponding rebates 8i and 8j of two adjoining panels 2i and 2j form a groove 9 which is filled with the concrete of the third layer 3.

 The bars 6a of the reinforcement at the joint plane between the two panels 2i and 2j are bent at 900 on the side of the groove 9, which, added to the concrete in this groove, improves the rigidity of the wall element. It will be noted that the uprights 6b and 6c are respectively embedded in the layers 1 and 3 and are in contact with the truss reinforcements 4 of these layers.

 The thermal bridge created along the joint plane 5 between two panels 2i and 2j has globally negligible effects as regards the thermal insulation properties of the wall element.

 The manufacture of a wall element according to the invention is carried out flat in a parallelepiped mold of appropriate dimensions. The first layer 1 of concrete is first poured with its truss reinforcement 4. On this still wet layer, the panels 2i are put in place next to each other so that they adjoin each other.

Then, at the joint planes 5 between two panels 2i and 2j, the ladder reinforcements 6 are inserted by driving them into the still wet concrete of the layer 1 and this until their lower uprights 6b touch the trellis 4 of the first layer 1. The trellis 4 of the layer 3 is then placed so that it rests on the upper uprights 6c of the ladder frames 6 and the third layer 3 is poured which is surface on its upper face.

 There is shown in Figs. 4a to 4c the assembly of wall elements according to the invention. In Fig. 4a, two elements lOa and lOb form a partition. They are provided, according to their height and at their end, with a groove Ila and llb substantially in the shape of a trapezoid. The two grooves 11a and 11b form a channel 12 in which concrete is poured. Pins 13a and 13b are embedded in the external layers 3a and 3b of the elements 10a and 10b and their loops are superimposed inside the channel 12. Inside the loops of the pins 13a and 13b passes a bar 14.

 In the gap 15 between the two elements 10a and 10b is provided a seal.

 Layers 16a and 16b of a thermal insulating material are provided, in the internal layers la and lb of each of the elements 10a and 10b, substantially at the intersection, so that they are respectively in contact, on the inner side, with the insulating layers 2a and 2b of the corresponding elements. The two layers 16a and 16b are end to end. They avoid the creation of thermal bridges at the intersection of two elements lOa and lOb. Pins 17a and 17b are provided at the end of each of the elements 10a and 10b to reinforce them.

 Fig. 4b shows an assembly substantially equivalent to that described in relation to FIG. 4a but applied to the intersection of two elements lOa and lOb in a corner. We find the same elements including the channel 12, the pins 13a and 13b and the two thermally insulating layers 16a and 16b. These connect, in a way, the layers 2a and 2b of insulating material of the elements 10a and 10b.

 Fig. 4c shows the intersection of two elements îOa and lOb forming a wall giving on the outside and, perpendicular to these elements and on the inside, a reinforcing wall 18 of concrete provided with reinforcement 19. The wall 18 has a tenon at the end 20 which is embedded in rebates of the two elements lOa and lOb, against their insulating layers 2a and 2b. These are end to end. A first pin 21 of the cross wall 18 has its loop inside the tenon 20 and a second pin 22 in "V" has, on the one hand, these ends which are respectively embedded in the external layers 3a and 3b of the elements lOa and lOb and, on the other hand, its loop which is superimposed on that of the first pin 21. A bar 22 which passes inside the loops of pins 21 and 22 is embedded in the post 18. This assembly also allows avoid the creation of thermal bridges.

Claims (9)

 1) Prefabricated element of reinforced concrete wall provided with a layer of thermally insulating material and capable of being manufactured flat in a mold, characterized in that it consists, from the inner face to the outer face, of a first layer (1) of concrete, layer (2) of insulating material and a third layer (3) of concrete of thickness close to the thickness of the first layer (1), the insulating layer (2) being consisting of a plurality of panels (2a to 2e) joined by their long sides, a ladder frame (6) whose bars (6a) are in the direction of the thickness of the wall and whose uprights (6b and 6c) are respectively embedded in the first layer (1) and in the third layer (3) located in each joint plane (5) between two contiguous panels (2i and 2j).  2) Element according to claim 1, characterized in that the concrete layers (1 and 3) are reinforced with a lattice reinforcement (4), the uprights (6b and 6c) of each reinforcement (6) being in contact with the truss reinforcement (4) of the corresponding concrete layer (1 or 3).  3) Element according to claim 1 or 2, characterized in that the panels (2a to 2e) have, on their large faces, grooves (7) longitudinal and rectangular profile or dovetail.  4) Element according to one of the preceding claims, characterized in that at the joint plane (5) between two panels (2i and 2j), each of these panels (2i and 2j) has a longitudinal rebate (8i and 8j) , the rebates (8i and 8j) forming a groove (9) which is filled with concrete of the third layer (3) of concrete.  5) Element according to one of the preceding claims, characterized in that the bars (6a) of the frame (6) at the joint plane (5) between two panels (2i and 2j) are bent at 900 on the side of the groove ( 9) formed by the rebates (8).  6) Method for manufacturing a wall element according to one of claims 2 to 5, characterized in that it consists in:  a) sink, with its lattice frame (4), the first  layer (1) of concrete in a mold of appropriate dimensions,  b) on this first layer (1) of concrete still wet,  put in place the panels (2i) constituting the layer (2) of  thermally insulating material so that they are joined  by their long sides,  c) insert, at each joint plane (5) between two panels  contiguous (2i and 2j), a reinforcement (6) in scale by pushing it  in the wet concrete of the first layer (1) until its  lower upright (6b) comes to touch the truss reinforcement (4)  of the first layer (1),  d) place the trellis (4) of the third layer (3) of  so that it rests on the upper uprights (6c) of the  ladder frames (6),  e) pour the concrete of the third layer (3) and surface its  upper side.  7) mounting of two prefabricated wall elements according to one of claims 1 to 5, characterized in that grooves (lla and llb) are respectively provided, depending on their height, on the wall elements (lOa and lOb) to form a channel at the intersection of the two elements (lOa and lOb), in said channel being poured concrete, plates of insulating material being embedded in each internal layer (la and lb) at the intersection of the two elements (lOa and lOb) elements (lova and lOb) and being respectively in contact with the insulating layers (2a and 2b) of the elements (10 and lOb), said plates (16a and 16b) being end to end in the assembly.  8) Assembly of wall elements according to one of claims 1 to 5 and a cross wall on the interior side, characterized in that there is provided, at the end of the cross wall, a stud (20) which is embedded in rebates elements (lova and lOb) against the insulating layers (2a and 2b) of the elements (lOa and lOb), said insulating layers being end to end.  9) An assembly according to claim 8, characterized in that a first pin 21 of the cross wall has its loop inside the stud (20) and that a second pin (22) has its ends respectively embedded in the layers external (3a and 3b) elements (lOa and lOb) and has its loop embedded in the stud (20), a bar (22) passing inside the loops of the first and second pins (21 and 22).