EP0015213B1 - Self supporting roof for buildings, composed of modular vaulted elements - Google Patents

Abstract

A self-supporting roof for buildings, composed of modular elements each comprising an outer wall, a layer of heat insulating material, an inner wall carried by the outer wall and of the same form to support the insulating layer, and stiffening frame members secured to the outer wall wherein the inner wall is also rigidly secured to said frame members so as to form with the outer wall a unitary structure vis-a-vis the efforts.

Description

The present invention relates to a self - supporting roof, in particular for industrial buildings, formed of long - span modular elements, in the form of an arch, in accordance with the preamble of claim 1.

It is known from FR-A-1558925 to use modular roof elements with oblique planes, comprising a self-supporting outer shell or wall conferring mechanical resistance to the element, a layer of thermal insulation and an inner wall supporting the layer insulation and carried by the outer wall, the latter being further stiffened by metal elements, such as "omega" irons welded to the shell. The roof elements are prefabricated in the factory, the work remaining to be done on the site essentially consists of putting the elements in place and assembling them to form the total roof.

FR-A 2147866 describes a roof of the same type as that of FR-A 1558925, specifying that it is composed of longitudinal elements resting on a horizontal structure and each consisting of an inverted V hull, and folded transverse stiffening frames so as to present a geometry congruent to the cross section of the shell.

The patent FR-A-1494733 describes a self-supporting structural element comprising two ribbed sheets arranged face to face and joined together by insulating rods. The roof thus produced can be flat or composed of vaults.

None of the above prior documents provide the structure with perfect rigidity, in particular by avoiding relative displacement of the two walls which constitute this structure.

The invention specifically aims to increase the bending moment of the roof and reduce the dead weight to bear while avoiding the existence of thermal bridge between the two inner and outer walls.

For this purpose, it is provided in accordance with the invention that the inner wall is, like the outer wall, self-supporting and arranged parallel to it and that the longitudinal edges of the two walls and the edges of the stiffeners are fixed to bars of longitudinal stress.

The association thus produced of the two walls, of their stiffeners and of the stress bars, leads to a self-supporting unitary structure which is not found in the documents cited above and which ensures a good distribution of the forces from one wall to the other, therefore involves the inner wall in the overall strength of the roofing element.

In one embodiment, the stiffeners are tubes of rectangular section filled with a thermal insulator, for example a foam of synthetic material, to prevent them from forming a thermal bridge.

In another embodiment, the stiffeners are formed by spaced sections fixed respectively to the inner and outer walls, between which are fixed at intervals spacer pieces.

The roofing elements according to the invention have the shape of a vault, the walls being formed for example of curved ribbed sheets.

• - la figure 1 montre en coupe la structure d'une toiture autoportante selon l'invention, formée d'éléments cintrés;
• - la figure 2a est une vue partielle en coupe suivante le plan III-III de la figure 1, montrant la forme d'un raidisseurs;
• - la figure 2b montre une variante par rapport à la réalisation de la figure 2a;
• - la figure 3 est une vue de détail à grande échelle de l'extrémité d'un élément de toiture selon la figure 1;
• - la figure 4 montre en coupe un élément de toiture cintré selon une variante de réalisation;
• - la figure 5 montre l'élément de toiture de-la figure 4 en vue de côté;
• - la figure 6 est une vue en coupe de détail montrant la forme d'un raidisseur.

The invention will be clearly understood on reading the following description, made with reference to the accompanying drawings. In the drawings:

• - Figure 1 shows in section the structure of a self-supporting roof according to the invention, formed of curved elements;
• - Figure 2a is a partial sectional view along the plane III-III of Figure 1, showing the shape of a stiffener;
• - Figure 2b shows a variant with respect to the embodiment of Figure 2a;
• - Figure 3 is a detail view on a large scale of the end of a roofing element according to Figure 1;
• - Figure 4 shows in section a curved roof element according to an alternative embodiment;
• - Figure 5 shows the roofing element of-Figure 4 in side view;
• - Figure 6 is a detail sectional view showing the shape of a stiffener.

FIG. 1 shows two elements 1 of a freestanding roof for an industrial building.

Each element has in section a substantially semicircular shape open upwards, with a width which can be around 2 meters, and can have a length of up to 30 meters. The elements are supported at their ends by supports symbolized in A, which can be constituted by the front walls of the building.

Each element includes an outer wall 2 and an inner wall 3 curved identically and with the same mechanical strength. Between these walls are arranged, at regular intervals in the longitudinal direction, transverse stiffeners conforming to the shape of the walls (see FIG. 5 for this arrangement) and one of which is shown in section in FIG. 2a.

The stiffeners 4 of FIG. 2a is a square section tube which is fixed, on the one hand, to the external wall 2 and, on the other hand, to the internal wall 3 by any suitable means, preferably by self-tapping screws. -drills and self-tapping symbolized by the mixed lines.

Between the walls 2 and 3 is placed a layer of thermal insulator 5, for example glass wool. The stiffeners 4 are themselves filled with a thermal insulator 6, for example a polyurethane foam formed in place, in order to prevent the stiffeners 4 from forming thermal bridges. To improve the insulation, there is also interposed, during the manufacture of the element, a layer of glass wool between the stiffeners and the walls, this layer then being crushed when the fixing is carried out as indicated by the reference. 7.

FIG. 2b shows a variant with respect to the embodiment of FIG. 2a, in which the irons 10, 11 having spread wings are fixed respectively to the walls 2 and 3, and between the irons 10 and 11 are placed at regular intervals from the pads 12 of rigid thermally insulating material, for example of wood or of rigid plastic. The connection between the bars 10 and 11 is ensured by clamping pieces 13, 14 respectively enclosing the pads 12 and connected by blocking a nut 15 on a bolt 16.

The walls 2 and 3 are, in the embodiment of Figure 1, made of steel trays, that is to say of ribbed steel sheets. These containers are commercially available and each wall will be formed from one or more of these containers, depending on the required width. If a wall includes several tanks, the connection will be obtained by covering the waves (or ribs) and fixing by screws. ____

To strengthen the resistance to longitudinal stresses of the end parts of the roofing element, as shown in FIG. 3, longitudinal profiles 17 are provided, housed in the last wave of the outer wall 2, and likewise longitudinal profiles 18 housed in the last wave of the inner wall 3. Each of these profiles working in compression since the arch is open upwards is placed between two stiffeners 4 consecutive and is fixed by its ends on plates 19 welded on the stiffeners 4.

Between two adjacent roofing elements are arranged connecting bars 20 forming spacers, which are fixed to the exposed ends of the stiffeners 4. Above the connecting bars 20 is placed a sealed ridge 21, and under the bars 20 is a sub-ceiling 22 supported by the upper face of the compression profiles 18. A layer of thermal insulation 23 is placed on the sub-ceiling 22.

A simple translucent skylight could also be placed between two adjacent roof elements.

The advantages of the roof according to the invention are as follows.

Thanks to the rigid connection established between the inner and outer walls by the stiffeners 4, and by the compression profiles, the inner wall 3 contributes by its own resistance to the rigidity of the roof, instead of forming a dead weight than the wall exterior must support, as in the prior art mentioned above. This makes it possible to increase the range of an element or, for a given range, to reduce the thickness of the walls.

On the other hand, the roof elements 1 are prefabricated in the factory and the only operations remaining to be carried out on the site are the installation of the elements 1 on the support walls and the installation of the connecting bars, the ridge, etc. ., between elements 1.

FIG. 4 shows an alternative embodiment in which two compression profiles are provided, constituted by tubes of square section 25, 26 extending continuously over the entire length of the roofing element, instead of d 'be placed between the stiffeners in the waves of the walls, as shown in Figure 3. In this variant, all the stiffeners 27 have their ends fixed respectively to the profiles 25, 26.

Such a variant reinforces the role of transmission of forces between the walls played by the compression profiles. The profiles 25, 26 are also, like the tubular stiffener of Figure 2a, filled with a thermal insulation foam formed in place.

The stiffeners also have a different structure from what has been described above. They are each formed of two T sections 28a, 28b fixed respectively to the outer wall and to the inner wall, preferably by means of self-tapping screws, not shown. The sections 28a, 28b are separated and joined at intervals by metal parts 29 welded to the cores of the sections 28a, 28b. Such an embodiment has the advantage of great simplicity of implementation.

Claims (3)

1. Self-supporting roof for buildings, composed of modular elements in the shape of a vault each comprising a self-supporting outer wall (2) and an inner wall (3) of same shape extending longitudinally between two supports, stiffening members (4, 27) of a shape corresponding to the cross- section formed by the outer (2) and inner (3) walls and transversaly disposed between the two walls (2, 3) at spaced intervals and fixed to said walls, and a layer of heat insulating material (5) disposed between the two walls (2, 3) and supported by the inner wall (3), characterized in that the inner wall (3) is itself also self-supporting and disposed parallel to the outer wall (2), that there are provided longitudinal compression bars (17, 18) to which are fixed the longitudinal edges of both walls (2,3) and the edges of the stiffening members (4, 27).

2. Roof according to claim 1, characterized in that spacer pads (12) made of insulating material are fixed between irons (10, 11) having diverging flanges which from the stiffening members (4), said irons (10, 11) being respectively fixed to the inner (3) and outer (2) walls and clamping members (13, 14) connected to each other are positioned on either side of the pads (12) against the outside of said iron flanges (10, 11).

3. Roof according to claim 1, characterized in that each stiffening member is formed by two profiles (28a, 28b) having a T-section, spaced from each other, respectively fixed to the inner (3) and outer (2) walls and connected, at spaced intervals, by plates (29).

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