EP1427897B1 - Insulating high-performance rough timber boarding for constructing floors - Google Patents

Abstract

The invention concerns a rough timber boarding comprising a body made of insulating material, for example expanded polystyrene, delimited by an upper surface (12), a lower surface (14), and two opposite end edges (16, 18) and wherein the upper surface extends through two support edges (20, 22) which extend mutually in parallel and between the two end edges to form each a support rebate designed to be nested on a fixed support, in particular on a beam heel. The upper surface (12) delimits ribs (48) which extend in a direction globally parallel to the end edges (16 and 18), thereby enabling to reduce the minimum thickness of a concrete slab subsequently cast on the rough timber boarding and to reinforce the support. The invention is useful for constructing concrete floors in the building sector.

Description

The invention relates to the field of building construction and more particularly relates to a high performance insulating interjoists for the construction of floors, as defined in claim 1. Such insulating interjoists are known from the document FR-A-2,486,985 .

Entrevous, also called hourdis, are intercalated pieces that are placed horizontally to come to rest on fixed supports, usually horizontal parallel beams, to be used for formwork concrete floor.

Insulating interjoists of this type are already known which comprise a body of insulating material, for example made of expanded polystyrene, bounded by an upper face, a lower face and two opposite end edges. The upper face is extended by two support flanges which extend parallel to each other, and between the two end slices, to each form a support rebate turned towards the lower face and adapted to fit on a support fixed, especially on a beam heel.

For the construction of a floor, one must first have a number of horizontal and parallel beams at given intervals, for example every 60 cm, and then set up interjoists before pouring the concrete slab on the structure and obtained.

These interjoists thus fulfill a function of formwork for the casting of the slab and a thermal and sound insulation function, since they remain in place after the casting of the slab.

In view of the increasingly stringent standards required in the construction of buildings, interjoists must have high specifications and performance, both mechanical and thermal, in order to be certified by the recognized organizations.

In particular, these interjoists must have a high mechanical strength to withstand loads of significant importance during their implementation. Furthermore, it is necessary that these interjoists can be cut easily to allow their introduction when the inter-axis or interval between two beams is reduced or even when it comes to setting up a interjoists between a beam and a support of a different nature, for example a wall.

In known interjoists of this type, the upper face (also called extrados) is flat and smooth and is intended to allow the formwork of a concrete slab, also called compression slab, whose minimum thickness is 5 cm. To resist during the implementation phase, it is necessary that the interjoists has a high mechanical strength that is usually obtained by increasing the density of the plastic used, in particular polystyrene.

Generally, the body of known interjoists is hollowed out by the presence of a number of cells which are intended to reduce the mass of the insulating material to lighten the interjoists.

However, the realization of these cells is difficult because it must not compromise the mechanical strength of the interjoists.

The invention is essentially intended to provide an insulating interjoists of the aforementioned type which is endowed with high mechanical and thermal performance to adapt to the current needs of the market and economically respond to current specifications.

In particular, it aims to provide an insulating interjoists of a particular design allowing a reduction of the volume of cast concrete implemented compared to the prior art.

The invention also aims to provide such interjoists that allows easy cutting on site to be able to support a beam on reduced inter-axis or between joists and floor banks.

It also aims to provide a type of interjoists that can be properly positioned during implementation on site to improve safety.

The invention proposes for this purpose an insulating interjoists as defined in the revendicaiton 1.

The presence of these ribs on the central part of the upper face of the interjoists results in a ribbing, complementary shape, the underside of the concrete slab, which reduces the minimum thickness of concrete. In this way, the minimum thickness above the ribs is typically about 40 mm instead of 50 mm in the prior art. This arrangement leads to a lower consumption of concrete, while maintaining an inertia equivalent to that of a slab of 50 mm constant thickness.

These ribs are advantageously formed on the whole of the upper face and also on the support flanges.

Characteristically, each of the ribs comprises a central portion formed on a central portion of the face upper and prolonged on both sides by two extremal sloping portions, formed respectively on two inclined portions of the two support flanges.

The ribs preferably have a substantially rectangular or trapezoidal profile and thus define between them grooves having a similar profile.

In other words, the upper face of the interjoists is formed by an alternation of ribs and grooves which constitute an original form which derogates from the usual general requirements. This feature not only reduces the thickness, but also significantly increase the mechanical strength of interjoists and thus the safety of workers during the implementation phase.

According to another characteristic of the invention, the interjoists comprise cells of chosen shape which extend in a direction parallel to the support flanges and which open into a first end wafer and are closed by a second wafer. end, so as to form blind cells.

In this regard, the invention aims to achieve cells of optimized shape to meet at least two objectives, on the one hand, an optimal thermal performance and, on the other hand, a sizing of the cells for an optimized cutting interjoists.

For this, the cells advantageously have a section of generally rectangular shape.

The invention also provides that the cells comprise a row of cells called "demodulation cells" which extend in a direction generally parallel to the upper face and the lower face and which are positioned and dimensioned, relative to the dimension of the fixed supports, in particular of the strut heels, so as to provide a support rabbet by an appropriate cut of the interjoists.

According to another particularity of the invention, the rank of demodulation cells extends between a first row of cells on the side of the upper face and a second row of cells on the side of the lower face.

According to yet another feature of the invention, the interjoists comprises a sheath passage formed on the upper face near one of the support flanges and extending across the ribs. This passage constitutes a reservation for the installation of ducts incorporated in the floor.

The invention also provides two centering profiles respectively formed on opposite parts of the support rabbets to ensure the correct positioning of the interjoists between two support beams.

The invention also provides that the support rabbets have an angled profile and they may include a corner reinforcement, so as to enhance the resistance of interjoists in a particularly stressed region.

According to yet another characteristic of the invention, the interjoists comprise, on the one hand, a tongue extending the lower face on the side of one of the support flanges and having an end edge and, on the other hand , a complementary profile cavity formed on the side of the other support and adapted to receive a tongue of an adjacent interjoists. The definition of the boundary between two interjoists allows the implementation "in contact" by tilting the interjoists on a support beam.

The interjoists, once nested in the interjoin adjacent, delimits a housing adapted to the shape of at least a portion of a support beam.

It is also expected that the interjoists comprises a locking latch formed on the upper face and adapted to receive a formwork riser.

It is advantageous that one of the end slices of the interjoists comprises a socket-forming cavity, while the other of the end slices comprises an extension forming a male interlock, which may constitute a third support on a load-bearing wall, thus increasing safety on site.

As already indicated, the interjoists of the invention is made of an insulating plastic material, in particular of the polystyrene type.

- la Figure 1

est une vue en perspective d'un entrevous isolant selon l'invention à partir d'une première tranche d'extrémité ;

- la Figure 2

est une vue en perspective de l'entrevous de la Figure 1 à partir d'une deuxième tranche d_'extrémité ;

- la Figure 3

est une vue de face de la première tranche d'extrémité ;

- la Figure 4

est une vue de face de la deuxième tranche d'extrémité ;

- la Figure 5

est une vue en coupe transversale de l'entrevous des figures précédentes ;

- la Figure 6

montre les extrémités respectives de deux entrevous adjacents prenant appui sur une même poutrelle ;

- la Figure 7

montre un entrevous découpé mis en place entre une poutrelle et un mur d'appui ;

- la Figure 8

est une vue analogue à la Figure 7 dans une autre configuration ;

- la Figure 9

montre la mise en place d'un entrevous découpé entre deux poutrelles à entre-axe réduit ; et

- la Figure 10

est une vue analogue à la Figure 9 dans une autre configuration.

In the description which follows, made only by way of example, reference is made to the appended drawings, in which:

- Figure 1

is a perspective view of an insulating interjoists according to the invention from a first end wafer;

- Figure 2

is a perspective view of the interjoists of the Figure 1 from a second bracket _end;

- Figure 3

is a front view of the first end slice;

- Figure 4

is a front view of the second end slice;

- Figure 5

is a cross-sectional view of the interjoists of the preceding figures;

- Figure 6

shows the respective ends of two adjacent interjoists supported on the same beam;

- Figure 7

shows a carved interjoists placed between a beam and a wall of support;

- Figure 8

is a view similar to the Figure 7 in another configuration;

- Figure 9

shows the establishment of a interjoists cut between two beams at reduced inter-axis; and

- Figure 10

is a view similar to the Figure 9 in another configuration.

The insulating interjoist 10 shown in Figures 1 to 4 comprises a body of insulating material, preferably expanded polystyrene with high density. This body is limited by an upper face 12 (also called extrados), a lower face 14 (also called intrados), a first end portion 16 (better visible on the Figures 1 and 3 ) and a second end portion 18 (better visible on the Figures 2 and 4 ). The faces 12 and 14 extend in generally parallel planes which are in a horizontal position in the position of use of the interjoists. As will be seen below, the two end slices 16 and 18 are opposite, the slice 16 constituting a female interlock and the slice 18 a male interlocking.

The upper face 12 is extended by two support flanges 20 and 22 which extend parallel to each other, and between the two end slices, to each form a support rebate 24, respectively 26, turned towards the lower face. and fit to fit on a fixed support, as will be seen later.

The upper face 12 comprises a central portion 28 which is generally parallel to the lower face 14 and which is extended, on either side, by two inclined portions 30 and 32 leading respectively to the bearing flanges 20 and 22 (FIG. Figures 3 and 4 ).

The support rabbet 24 has a suitable profile. It has a generally horizontal face 24a which is connected, on the one hand, to a substantially vertical upper face 24b forming the end of the support rim 20 and, on the other hand, to a substantially vertical face 24c which is connected to it. -Even a face 24d generally horizontal delimiting the upper part of a tongue 34 which extends the underside of the interjoists. Correspondingly, the support rabbet 26 has faces 26a, 26b and 26c which form the symmetry of the faces 24a, 24b and 24c of the rabbet 24.

The faces 24a and 24c of the rebate 24, as well as the faces 26a and 26c of the rabbet 26, have an angled profile, substantially greater than 90 °. They may each comprise a reinforcement (not shown) preferably constituted by an insert of resistant material, for example an adhesive tape, placed in the angled profile.

The tongue 34 which extends the lower face 14 of the side of the bearing flange 20 has an end edge 36 disposed obliquely with respect to the lower face 14 and the face 24d, these two faces being parallel to each other. Thus, the tongue 34 is delimited by two parallel faces (the lower face 14 and the upper face 24d) and by an oblique face 36 which forms a continuous edge extending parallel to the direction of the bearing flanges 20 and 22.

On the opposite side, the interjoists are limited by an inclined edge 38 adapted to receive an edge 36 of an adjacent interjoists, as can be seen in FIG. Figure 6 .

The interjoists 10 of the invention are intended to be arranged each between two beams 40 (only one of which is shown on FIG. Figure 6 ) arranged horizontally and parallel to each other with a given center distance. These beams are generally made of reinforced or prestressed concrete. The beam 40 has a inverted T section and it comprises a generally vertical core 42 and a generally horizontal cross 44 forming two opposing heels 46. When two interjoists are placed on either side of a beam ( Figure 6 ), their respective bearing flanges are supported on the two heels of the beam, the tongue 34 of one of the interjoists passing under the beam 44 of the beam and coming by its edge 36 to be applied against the edge 38 of the beam the adjacent interjoists. Thus, the two intervous come to cover a part of the beam, leaving an upper part cleared for the subsequent pouring of concrete. This upper part of the beam will then be coated with concrete, thus ensuring a definitive connection between the beam and the concrete slab.

According to the invention, the upper face 12 delimits a plurality of ribs 48 which extend parallel to each other and parallel to the end slices 16 and 18. These ribs are formed on the whole of the upper face 12 and on the support flanges 20 and 22. Each of these ribs comprises a central portion 50 formed on the central portion 28 of the upper face and extended on either side by two end portions 52, 54 sloping, respectively formed on both bearing flanges and more particularly on the sloping portions 30 and 32 of the upper face.

The ribs 48 have a rectangular or substantially trapezoidal profile ( Figure 5 ) and they alternate with grooves 56 having a similar profile. The presence of these ribs reduces the minimum thickness of the concrete which will then be poured on interjoists placed between the beams. This ribbing makes it possible to reduce the minimum thickness of the concrete on the ribs to a value of the order of 40 mm. This arrangement leads to a lower consumption of concrete while maintaining an inertia equivalent to that of a tile of 50 mm constant thickness. In addition, it reinforces the mechanical strength of the interjoists, offering better safety to the workers.

The body of the interjoists is hollowed out by the presence of cells having a profile of chosen shape which open into the first end wafer 16 ( Figures 1 and 3 ) and are closed by the second end wafer 18 ( Figures 2 and 4 ). We thus realize blind cells, as we also see on the Figure 5 .

The end slice 16 ( Figures 1 , 3 and 5 ) comprises a cavity 58, while the end face 18 comprises an extension 60, of complementary shape, to form respectively a female interlock and a male interlocking. The presence of these interlocking meets two main objectives: to make an effective connection between two successive interjoists, and to ensure a support on three sides for a interjoists at the end of the span. These two points significantly improve the resistance of the interjoists vis-à-vis the movement of construction site personnel, while reducing the "edge effect".

The cells are arranged in three rows parallel to each other and parallel to the general direction of the upper face 12 and the lower face 14. They comprise an intermediate row of cells 62, called demodulation cells, (see FIG. Figure 3 ) which are four in the embodiment and which each have a generally rectangular shape, being delimited by an upper face 64, a lower face 66 and two side faces 68 and 70. As can be seen, the face upper 64 of each of the alveoli is substantially in alignment with the faces 24a and 26a of the support rabbets, while the lower face 66 of the cell is substantially at the same level as the face 24d of the tongue. Moreover, the faces 68 and 70 are substantially parallel to the faces 24c and 26c of the rabbets. As will be seen below, this provision makes it possible appropriate cutting of the interjoists, to reconstruct other support grooves when the interjoists must be placed between two beams with reduced between-axis, or between a beam and another support means.

The rank of the demodulation cells 62 extends between a row of cells 72 on the side of the upper face and a row of cells 74 on the side of the lower face. The cells 72 are, in the example, three in number and have a substantially rectangular or trapezoidal shape. The cells 74 are five in number and have a rectangular shape. In addition, a cell 76 of circular shape is formed in the tongue 34, at the same height as the cells 74.

As we see on the Figure 3 , the four cells 62 and the three cells 72 open into the cavity 58 forming female interlocking.

According to another characteristic of the invention (see Figures 1 to 4 ), the interjoists comprises a sheath passage 78 formed on the upper face near the bearing flange 22 and extending across the ribs 48. More particularly, this sheath passage is formed in the end portions 54 on a slope ribs 48 and it is a reservation dedicated to the passage of ducts incorporated in the floor. The particular position of this passage makes it possible not to significantly alter the resistance of the assembly. It avoids the anarchic placement of inserts that could be arranged in sensitive areas, from the point of view of resistance, interjoists.

Moreover, and as we see more particularly on Figures 1 to 4 , the interjoists comprises two centering profiles 80 and 82 respectively formed on the vertical faces 24c and 26c of rabbets 24 and 26. These centering profiles here have the shape of a half-round. They ensure the positioning the beams in the space between two interjoists by making contact at the tongue, which ensures maximum thermal performance,

These centering profiles make it possible to prevent the beam from shifting on one side of the interjoists, which would lead to a reduction in the depth of support on the facing face, thus creating a risk of rupture. premature of the interjoists concerned.

The interjoists further comprises a locking latch 84 ( Figures 1 and 2 ) formed on the upper face, in the example in the rib 48 located in the middle of the interjoists. This lock is adapted to receive a formwork riser (not shown) to achieve higher formwork heights than those obtained with the basic interjoists.

The interjoists include a mark 86 ( Figures 1 and 3 ) on the tongue, at the level of the wafer 16, and above the cell 76. This marking is intended to allow verification of the conformity of the product after pouring the concrete, by cutting the end of the tongue .

In addition, a marking 88 is formed on the male interlock 60 ( Figures 2 and 4 ) to enable the identification of the product. It provides information on the thermal performance of the finished floor.

As indicated previously (see in particular the Figure 6 ), interjoists are provided to be placed by line between successive beams 40 arranged parallel to each other and at regular intervals, typically 60 cm.

In certain circumstances, some of the interjoists must be supported either between a beam and a support wall, or between two beams whose center distance is reduced compared to in the normal inter-axis, as we will see in reference to Figures 7 to 10 . In the embodiment of the Figure 7 , the interjoists 10 has been cut to remove a portion (located on the left side of the figure), that is to say the side of the support flange 20. The bearing flange 22 (located on the right side on the figure) is supported on one of the heels of a beam 40.

The left part of the interjoists has been cut along a broken line L which comprises a vertical portion passing through a cell 72 of the upper rank, along a demodulation cell 62 and extended by another vertical line Lb, offset from at the line La and passing through a cell 74 of the lower rank. Thus, thanks to the offset of the lines La and Lb, a support edge 90 is formed which makes it possible to rest on a wall (not shown), the space E between the wall and the beam 40 being reduced with respect to the normal between-axis between two beams. It is also possible to cut the interjoists in other ways, as shown for example by the lines L 'and L ", or to cut parts of the interjoists in areas close to the beams to further discover the beam and improve the connection between the concrete and the beam.

In the embodiment of the Figure 8 it is the right part (in the figure) of the interjoists, that is to say the one on the side of the flange 22, which has been removed. By against the support flange 20 is supported on a beam 40 similar to that described above. Cutting is also carried out by a line L comprising two vertical parts La and Lb offset relative to each other to form another support flange 92. There again, other cuts, as shown by the lines L 'and L ", are possible.

In the embodiment of the Figure 9 , the interjoists has been cut to fit between two beams 40 having a reduced center distance E. In the example, this is the part of the side right of the interjoists (on the figure) that was removed. The cut is effected by a line which partly passes through a demodulation cell 62, in the example the one located closest to the support flange 22 (which has been removed). As a result, it is the upper face 64, the vertical face 68 and the lower face 66 of this cell 62 which cooperate to provide a profile receiving one of the heels of the beam. It is possible to cut the interjoists in other ways to fit beams whose inter-axis E is even smaller than that shown on the diagram. Figure 9 . In this case, we can take support in the recess formed by one or other of the other three cells.

In the embodiment of the Figure 10 , the interjoists was cut to support also between two joists reduced inter-axis, the right part of the interjoists (in the figure) having been removed by a cut made in another way.

It is understood that other types of cutouts can be envisaged to adapt the intervous to particular supports.

In any case, the optimized shape facilitates the adaptation of the interjoists to each particular circumstance, without compromising either the thermal performance or the mechanical strength of the floor in use.

Improved performance insulating interjoists are thus used for the construction of concrete slabs in a wide range of buildings.

Claims (16)

1. An insulating block for making floors, the block comprising a body of insulating material defined by a top face (12), a bottom face (14), and two opposite end faces (16, 18), the top face (12) having a central portion (28) that is generally parallel to the bottom face (14) and extended by two inclined portions (30, 32), the inclined portions (30, 32) being extended respectively by two bearing rims (20, 22) that extend parallel to each other between the two end faces such that each forms a bearing rabbet (24, 26) facing towards the bottom face and suitable for engaging on a stationary bearing surface, in particular on a flange of a joist (40), the top face defining ribs that extend in a direction generally parallel to the end faces (16, 18), the block being characterized in that each rib (48) comprises a central portion (50) formed on the central portion (28) of the top face (12).
2. An insulating block according to claim 1, characterized in that the ribs (48) are formed over all of the top face (12) and over the bearing rims (20, 22).
3. An insulating block according to claim 2, characterized in that each of the bearing ribs (48) comprises a central portion (50) formed on a central portion (28) of the top face (12) and extended at each end by two respective sloping end portions (52, 54) formed respectively on the two inclined portions (30, 32) that extend the central portion (28) of the top face (12).
4. An insulating block according to any one of claims 1 to 3, characterized in that the ribs (48) are of a substantially rectangular or trapezoidal profile and define between them grooves (56) of analogous profile.
5. An insulating block according to any one of claims 1 to 4, characterized in that the body includes cells (62, 72, 74, 76) of selected shape that extend in a direction parallel to the bearing rims (20, 22), that open out into a first end face (16), and that are closed by a second end face (18) so as to form cells that are blind.
6. An insulating block according to claim 5, characterized in that the cells (62, 72, 74) have a section that is generally rectangular in shape.
7. An insulating block according to claim 5 or claim 6, characterized in that the cells comprise a row of demodulation cells (62) extending in a direction that is substantially parallel to the top face (12) and to the bottom face (14), which cells are positioned and dimensioned in such a manner as to provide a bearing rabbet by appropriately cutting (L) the block.
8. An insulating block according to claim 7, characterized in that the row of demodulation cells (62) extends between a first row of cells (72) beside the top face (12) and a second row of cells (74) beside the bottom face (14).
9. An insulating block according to any one of claims 1 to 8, characterized in that it includes a duct passage (78) formed in the top face (12) close to one of the bearing rims (22) and extending through the ribs (48).
10. An insulating block according to any one of claims 1 to 9, characterized in that it has two centering profiles (80, 82) formed respectively on opposite portions (24c, 26c) of the bearing rabbets (24, 26).
11. An insulating block according to any one of claims 1 to 10, characterized in that the bearing rabbets (24, 26) have an angled profile and may include angled reinforcement.
12. An insulating block according to any one of claims 1 to 11, characterized in that it includes firstly a tongue (34) extending the bottom face (16) beside one of the bearing rims (20) and including an end edge (36), and secondly a cavity (38) of complementary profile formed beside the other bearing rim (22) and suitable for receiving a tongue of an adjacent block.
13. An insulating block according to claim 12, characterized in that the block (10), once engaged on the adjacent block (10) defines a housing matching the shape of a portion of a bearing joist (40).
14. An insulating block according to any one of claims 1 to 13, characterized in that it includes a blocking catch (84) formed on the top face and suitable for receiving a shuttering raising block.
15. An insulating block according to any one of claims 1 to 14, characterized in that one of the end faces (16) includes a cavity (58) forming a female engagement, while the other end face (18) includes an extension (60) forming a male engagement.
16. An insulating block according to any one of claims 1 to 15, characterized in that it is made by molding an insulating plastics material, in particular polystyrene.

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