Concrete floor with a wooden element for fastening wooden beams to a concrete slab

Description

Domaine technique de l'invention

[0001] The invention relates to a concrete floor comprising at least one beam having a main axis, a concrete slab which is poured so as to rest on an upper face of the beam, a metal reinforcement which is taken into the slab, the beam being connected to the concrete slab by at least one added connecting element which is fixed to the beam and at least part of which is taken into the concrete slab. Arrière-plan technique

[0002] The construction of concrete floors is already widely known in the field of building construction, particularly residential buildings. The invention relates more particularly to the construction of concrete floors with beams.

[0003] Such a beam floor comprises a supporting structure of prefabricated concrete beams arranged parallel to each other at regular spacing, for example approximately every 60 cm. Reinforced concrete beams, prestressed concrete beams with continuous steel bars and beams with latticework are known.

[0004] A concrete compression slab, called a "floor slab", with a thickness of between 4 cm and 10 cm, for example, is poured with a reinforcing element, such as a welded mesh, onto the supporting structure. For this purpose, formwork is placed between the beams. An upper part of the beams is directly embedded in the concrete to ensure the slab is fixed to the beams. Numerous metal reinforcement elements are also provided to reinforce the slab and to further improve the fixing of the slab to the beams. The compression slab ensures the rigidity of the floor and allows the loads to be transferred to the beams.

[0005] The space provided between two adjacent joists is often filled with interlocking blocks, sometimes also referred to as "floor joists" by misnomer. Interlocking blocks can serve as formwork for the compression slab that covers them. Depending on the shape and material used, interlocking blocks have a load-bearing role or not. They also help to enhance the performance of a floor, for example, thermal or sound insulation.

[0006] However, such a beam floor has the disadvantage of using many non-renewable raw materials, including steel used for reinforcement. In addition, the production of concrete beams consumes a lot of energy. Document DE 10 2007 052455 A1 discloses the features of the preamble of claim 1.

[0007] The invention aims to obtain a concrete beam floor with preserved mechanical properties while reducing the use of non-renewable raw materials, in particular steel, and reducing its carbon footprint. Résumé de l'invention

[0008] The invention provides a concrete floor comprising the characteristics of claim 1.

[0009] Such a floor limits the use of concrete and metal elements. The construction of wooden elements requires much less energy than the construction of equivalent elements in metal and concrete.

[0010] According to the invention, the connecting element is formed from a wooden strip which extends along a main longitudinal axis and which has a lower face for fixing to the beam and an upper face for contact with the concrete slab, the wooden strip comprising hollows produced by removal of material in its upper face into which the concrete of the slab is poured, the generally transverse walls delimiting the hollows being capable of transmitting the shear forces exerted generally longitudinally by the slab on the wooden strip during bending of the floor.

[0011] This feature ensures that the concrete slab remains fixed to the beams even in the event of significant flexion of the floor. In particular, it prevents the concrete slab from slipping relative to the beams.

[0012] According to another aspect of the floor produced according to the teachings of the invention, the hollows are formed by grooves which extend generally transversely.

[0013] Such hollows are easy, quick and inexpensive to make on wooden slats.

[0014] According to another aspect of the floor produced according to the teachings of the invention, the wooden strip is delimited by at least two edges which are provided with means to resist vertical tearing of the slab relative to the wooden strip.

[0015] It is indeed important to ensure that the slab cannot be torn off vertically in relation to the beams.

[0016] According to another aspect of the floor produced according to the teachings of the invention, the means for resisting tearing are formed by grooves which extend longitudinally and into which the concrete of the slab is poured.

[0017] As with grooves, such grooves are easy, quick and inexpensive to make on wooden slats.

[0018] According to another aspect of the floor produced according to the teachings of the invention, the means for resisting tearing are formed by a beveled shape of the edges.

[0019] This is a variant of the means of resisting tearing which are just as easy, quick and inexpensive to produce on wooden slats.

[0020] According to another aspect of the floor produced according to the teachings of the invention, the beam is made of soft wood, while the wooden strip is made of hard wood.

[0021] This ensures good elasticity and good breaking strength for the beam, while the wooden slats have a hardness that guarantees their function of fixing the concrete slab.

[0022] According to another aspect of the floor produced according to the teachings of the invention, the wooden strip is fixed by gluing its lower fixing face to the upper face of the beam.

[0023] According to another aspect of the floor produced according to the teachings of the invention, the lower face of the wooden blade attachment comprises longitudinal relief slots which make it possible to absorb the dimensional variations of the beam depending on the hygrometric conditions.

[0024] According to another aspect of the floor produced according to the teachings of the invention, the wooden strip is fixed to the beam by screwing or nailing.

[0025] According to another aspect of the floor produced according to the teachings of the invention, it comprises at least one wooden strip whose main longitudinal axis extends parallel to the main axis of the beams, called a stringer.

[0026] According to another aspect of the floor produced according to the teachings of the invention, at least one beam comprises a stringer which extends substantially over the entire length of the upper face of the section of the beam intended to receive the concrete slab.

[0027] According to another aspect of the floor produced according to the teachings of the invention, at least one beam comprises several side members which are distributed in an aligned manner over the entire length of the upper face of the beam intended to receive the concrete slab.

[0028] According to another aspect of the floor produced according to the teachings of the invention, it comprises: at least two beams each equipped with several longitudinal members spaced longitudinally by an interval, at least one wooden strip whose main longitudinal axis extends in a direction orthogonal to the main axis of the beams, called a crosspiece, and fixed to the face of each of the beams in the interval between two longitudinal members.

[0029] This feature allows part of the slab's support function to be carried out using wooden slats. This allows, in particular, to reduce the dimensions of the metal frame, and therefore the quantity of metal present in the floor.

[0030] According to another aspect of the flooring produced according to the teachings of the invention, the wooden slats are treated with a water-repellent product.

[0031] This feature prevents the water present in the concrete during the pouring of the slab from being absorbed by the wooden slats. Thus, the wooden slats are protected against rotting, while the concrete retains its mechanical characteristics, including at the interface with the wooden slats during setting.

[0032] The invention also relates to a method of producing a floor according to the teachings of the invention, characterized in that it consists of: fix at least one wooden strip on the upper face of each beam; arrange formwork and / or interlocks, the upper face of which is flush with the upper face of the beams so that the wooden strips protrude from the formwork and / or the interlocks; arrange a metal frame on the beams; pour a concrete slab which takes the metal frame and the wooden strips. Brève description des figures

[0033] Other characteristics and advantages of the invention will appear during the reading of the detailed description which follows for the understanding of which reference will be made to the appended drawings comprising the following figures. There figure 1 is a perspective view which represents a joist floor made according to the teachings of the invention which does not include interjoists. figure 2 is a view similar to that of the figure 1 which represents a floor made according to the teachings of the invention which includes interjoists inserted between the beams. The figure 3 is an exploded detail view showing a beam, a reinforced concrete slab and a wooden strip for fixing the concrete slab to the beam. figure 4 is a perspective view which represents a floor produced according to the teachings of the invention which is mounted to rest on the course of a wall of a building. The figure 5 represents a view similar to that of the figure 4 in which the floor produced according to the teachings of the invention is mounted resting on a wooden beam fixed to a wall or to a partition of a building. The figure 6 is an exploded perspective view of the floor of the figure 2 . There figure 7 is a perspective view which represents an end section of a wooden strip ensuring the fixing of the concrete slab with the beam on any of the floors produced according to the teachings of the invention, the wooden strip comprising rectilinear grooves. The figure 8 is a longitudinal sectional view along section plane 8-8 of the figure 1 which represents the wooden blade, here forming a stringer, which is fixed on the beam and taken into the slab to guarantee the fixing of the beam with the slab. The figure 9 is a top view which represents an alternative embodiment of the grooves equipping the upper face of the wooden blade of the figure 7 . There figure 10 is a top view which represents an alternative embodiment of the grooves equipping the upper face of the wooden blade of the figure 7 . There figure 11 is a schematic view in longitudinal section along a wooden strip taken from the slab, the wooden strip not being produced according to the teachings of the invention because it has no hollow in its upper face, the assembly formed by the wooden strip and the slab being in bending between two end supports, the bending being exaggerated for the purposes of the description. figure 12 is a view similar to that of the figure 11 in which the wooden blade is made according to the teachings of the invention and equipped with hollows allowing the absorption of shear forces. The figure 13 is a cross-sectional view along section plane 13-13 of the figure 8 , which represents the wooden blade with grooves to prevent it from being pulled vertically away from the slab. The figure 14 is a cross-sectional view similar to that of the figure 13 , which represents a variant of the wooden blade which is provided with beveled edges to prevent it from tearing vertically in relation to the slab. The figure 15 is a perspective view of a beam intended to be used to manufacture a floor according to the teachings of the invention in which the beam is equipped with wooden strips forming side members. figure 16 is a cross-sectional view along section plane 16-16 of the figure 1 which represents two beams equipped with stringers and formwork during the pouring of the concrete slab. The figure 17 is a cross-sectional view similar to that of the figure 16 which represents an alternative embodiment of the floor produced according to the teachings of the invention. The figure 18 is a perspective view similar to that of the figure 15 which represents the beam equipped with waterproof skirts for the individual transport of each beam to the building construction site. The figure 19 is a perspective view which represents two beams similar to that shown in the figure 18 between which interjoists are arranged after raising the waterproof skirt. The figure 20 is a view similar to that of the figure 19 in which the skirts have been folded down over the joists to form a waterproof surface. The figure 21 is a view similar to that of the figure 20 in which crosspieces were arranged on the beams. Description détaillée de l'invention

[0034] In the remainder of the description, elements having an identical structure or similar functions will be designated by the same references.

[0035] In the remainder of the description, longitudinal, vertical and transverse orientations will be adopted without limitation. The longitudinal and transverse directions are applied locally for each wooden strip 32. The vertical direction is indicated by the arrow "V" in the figures which is conventionally oriented from bottom to top. The term "horizontal" will be used to designate a plane parallel to the upper longitudinal transverse face of the floor slab, the vertical direction extending orthogonally to the horizontal upper face of the slab. For such a floor, the vertical direction often corresponds to the direction of gravity, however the invention is also applicable to floors intended to be inclined relative to the direction of gravity.

[0036] We have represented at the figures 1 And 2 a concrete floor 10 made according to the teachings of the invention.

[0037] The concrete floor 10 comprises at least one beam 12 having a main axis "X". Each beam 12 here has a rectangular cross-section. As shown in more detail in figure 3 , each beam 12 is delimited vertically by an upper face 14 and a lower face 16, and transversely by two lateral faces 18. As shown in the figure 4 , each beam 12 generally comprises two end sections 20 which are intended to allow it to rest on supports 16 and a central section, called the span section 22, which is intended to extend between the two supports 16.

[0038] As shown in the figure 4 , the support 16 can be formed by the level of a wall 23, by a support beam, called a sail working at the belt fixed to a wall 25, as shown in the figure 5 , or a metal shoe (not shown) which is fixed to a wall.

[0039] When the floor 10 has several beams 12, as shown in figures 1 And 2 , they are preferably arranged in parallel. The floor 10 here has four identical beams 12. They are spaced transversely by a spacing "E" relative to the axis "X" of the beams 12.

[0040] As a variant not shown, when the aim is to obtain a floor which is not rectangular in shape, the beams can be arranged in a manner which is not parallel to each other.

[0041] The floor 10 also has a concrete slab 24 which is poured so as to rest on the upper face 14 of the beam 12. The concrete slab 24 has the shape of a plate which is delimited vertically by an upper horizontal floor face 26 and a lower horizontal floor face 28. The slab 24 has a substantially constant vertical thickness, for example between 4 cm and 10 cm, preferably approximately 7 cm. In general, the slab 24 rests on the span section 22, while the end sections 20 protrude on either side of the slab 24.

[0042] The slab 24 is here reinforced by a metal reinforcement 30 which is taken into the concrete constituting the slab 24. The reinforcement 30 is shown in broken lines at figure 1 and it is visible on the exploded view shown in the figure 6 Here it presents the form of a grid-like lattice formed by crossing metal rods, particularly steel.

[0043] According to the teachings of the invention, the beam 12 is made of wood. This is, for example, a soft wood, such as coniferous wood, in particular spruce. Such wood has mechanical properties that are entirely suitable for construction, in particular in terms of breaking strength and elasticity. Furthermore, the use of a wooden beam 12 instead of a reinforced concrete beam, as is the case in the prior art, is a solution with numerous advantages, in particular from the point of view of environmental protection.

[0044] Unlike the state of the art, it is not possible to directly take the softwood beam 12 into the concrete forming the slab 24 to ensure the fixing of the slab 24 on the beams 12.

[0045] In fact, the concrete does not adhere sufficiently to the soft wood to guarantee the stability of the floor 10.

[0046] In addition, softwood has dimensions that are likely to vary depending on climatic conditions with a much greater amplitude than concrete. This therefore risks further weakening the adhesion between wood and concrete.

[0047] Furthermore, the softwood of the beam 12 risks absorbing the moisture contained in the concrete when the slab 24 is poured. This risks causing a structural disparity in the slab 24, the areas dried out too quickly by absorption of water being less resistant due to poor setting of the concrete than the areas where the water has evaporated more slowly. In addition, the water absorbed by the beams 12 risks causing play and, ultimately, causing fungal degradation to start in the softwood and thus significantly reducing the breaking strength of the beam.

[0048] To enable the slab 24 to be fixed relative to the beam 12, at least one additional connecting element is provided which is fixed to the beam 12, on the one hand, and at least one part of which is taken into the concrete slab 24, on the other hand.

[0049] Connecting elements are also made of wood. For example, this is wood treated to resist moisture, particularly by means of a water-repellent treatment. These are, for example, connecting elements made of hardwood, such as beech or oak.

[0050] The water-repellent treatment is carried out, for example, by applying one or more layers of a water-repellent product such as a varnish, possibly preceded by the application of a primer.

[0051] Each connecting element is, according to the invention, formed by a wooden blade 32 which extends along a longitudinal axis "L", as shown in more detail in figure 7 Depending on its orientation relative to the beam, this wooden blade 32 will subsequently be called stringer 32A or crosspiece 32B.

[0052] The wooden blade 32 has a lower horizontal face 34 for fixing to the beam 12 and an upper face 36 for contact with the concrete slab 24. The wooden blade 32 has lateral edges 38 which extend longitudinally and which join its lower face 34 to its upper face 36. The vertical thickness of the blade is generally much less than the dimensions of its lower and upper faces 34, 36, for example of the order of a centimeter.

[0053] The wooden blade 32 is more particularly intended to be taken into the concrete of the slab 24 over its entire thickness so that its lower face 34 is flush with the lower face 28 of the slab 24.

[0054] The wooden blade 32 comprises hollows 39 produced by removal of material in its upper face 36. These hollows are delimited at least in part by walls 40 extending generally transversely. The term "generally" means that the walls 40 may have an inclination in a horizontal plane relative to the main longitudinal axis "L", for example the walls 40 may form an angle of between 45° and 135° relative to the longitudinal axis "A" of the wooden blade 32. Thus, on the figure 7 , the grooves are inclined by approximately 10° relative to the longitudinal "L" axis.

[0055] As shown in the figure 8 , the wooden blade 32 here forming a spar 32A, the concrete of the slab 24 is poured into the hollow 39. Thus, after the slab 24 has hardened, the generally transverse walls 40 are capable of transmitting shear forces "C" exerted generally longitudinally by the slab to the wooden blade 32 during bending of the floor 10. This thus makes it possible to prevent the slab 24 from sliding longitudinally relative to the wooden blades 32.

[0056] According to a particularly easy embodiment to produce, the hollows 39 are formed by grooves which extend generally transversely. These are rectilinear grooves which extend from one lateral edge 38 to the other.

[0057] As a variant of the invention shown in figures 9 And 10 , the grooves forming the hollows 39 are formed by non-rectilinear grooves, such as chevrons or waves.

[0058] Thus, when a vertical force "F" is applied downwards in the middle of the floor 10, the latter flexed on its supports 16 in the longitudinal direction of the wooden strip 32, the floor tends to slide relative to the wooden strips. As shown in figure 11 , in the absence of the hollows 39, the ends of the slab 24 slide longitudinally outwards relative to the wooden blade 32. As shown in figure 12 , the hollows 39 made according to the teachings of the invention make it possible to very effectively avoid this sliding. The shear forces "C" exerted by the slab 24 on the wooden blade 32 are then absorbed by longitudinal compression of the concrete slab and by longitudinal traction of the wooden beam 12 which is glued under the wooden blade 32 (not shown). Now concrete is precisely known to be able to withstand significant compression forces, while wood has sufficient elasticity to absorb the same tensile forces.

[0059] The invention thus makes it possible to increase the bending rigidity of the floor 10 by associating the wooden beam 12 subjected to tension with the concrete slab 24 subjected to compression by means of the wooden blade 32 forming a very rigid connection element.

[0060] It is further provided to provide the wooden slats 32 with means to resist the vertical tearing of the slab 24 relative to the wooden slats 32.

[0061] For this purpose, as represented in figures 7 And 13 , the lateral edges 38 are here provided with grooves 42 which extend longitudinally. The concrete of the slab 24 is poured into the grooves 42. After the slab 24 has hardened, the grooves 42 are capable of transmitting orthogonal loosening forces to the slab 24 up to the wooden strip 32 in order to prevent the slab 24 from being torn away from the wooden strip 32.

[0062] According to an alternative embodiment of the means for resisting tearing shown in the figure 14 , the lateral edges 38 of the wooden blade 32 have a beveled shape so that the wooden blade 32 has, in cross section, a trapezoidal-shaped profile for dovetail fixing of the wooden blade 32 in the slab 24.

[0063] At least one wooden blade 32 which extends parallel to the main axis "X" of the beams 12, is called a stringer 32A. As shown in figures 6 And 8 , the side members 32A are intended to be fixed directly to the upper face 14 of each beam 12 in order to guarantee good fixing of the slab 24 to each beam 12. The side members 32A advantageously have the same width as the upper face 14 of the beam 12. They are here arranged so that their lateral edges 38 are in the extension of the lateral faces 18 of the beams 12. Thus, the shear forces applied to the side members 32A during bending of the assembly formed by the beam 12 and the slab 24 are distributed over a larger surface area.

[0064] Preferably, as shown in figure 6 , a beam 12 comprises several longitudinal members 32B which are aligned on the upper face 14 of the beam 12 which is intended to receive the slab 24. The longitudinal members 32A of the same beam 12 are arranged at a longitudinal distance from each other, with a regular interval "I", over the entire length of the upper face 14 of the beam 12 which is intended to receive the slab 24. The hollows 39 are distributed regularly on the upper face 36 of each longitudinal member 32A.

[0065] The cumulative length of the 32A side members is at least equal to and preferably greater than the cumulative length of the "I" intervals. Thus, the shear force is distributed over a greater length, limiting, or even eliminating, stress concentrations.

[0066] Alternatively, the side members 32A are distributed unevenly, with a greater density near the end sections 20, the density gradually decreasing as one approaches the middle of the span section 22. Indeed, the shear forces "C" are much greater near the end sections 20 bearing on the supports 16 than in the middle of the span section 22 of the beam 12.

[0067] According to another variant not shown, each beam comprises a spar which extends substantially over the entire length of the upper face of the beam which is intended to receive the slab. The hollows, in particular grooves, can then be distributed regularly over the entire length of the spar, or according to a gradual distribution in which the hollows, in particular the grooves, are arranged with greater density near the end sections 20, the density gradually decreasing as one approaches the middle of the span section 22.

[0068] Each spar 32A is preferably fixed by gluing its lower fixing face 34 directly onto the upper face 14 of the beam 12. The activation of the bonding can be carried out by slow polymerization, heating, friction, etc.

[0069] The side members 32A and the beams 12 are made of wood of different species which react in different ways to hygrometric variations. The beams 12 made of soft wood are in particular likely to have dimensions varying with a greater amplitude than the side members 32B made of hard wood according to the hygrometric conditions, dependent on humidity and temperature. When the side member 32A is fixed by gluing, to prevent it from coming loose under the effect of hygrometric conditions, the lower fixing face 34 of the side member comprises longitudinal relief slots 44 which make it possible to absorb the dimensional variations of the beam 12 according to the hygrometric conditions, as illustrated in figure 7 .

[0070] In a variant not shown, the side members can be fixed by nailing or screwing to the beams.

[0071] Optionally, it is also possible to further reduce the quantity of metal required for the frame 30 by equipping the floor 10 with wooden slats 32 extending along a main axis orthogonal to the axis of the beams 12, called crosspieces 32B. These crosspieces 32B are arranged across the beams 12. Thus, a crosspiece 32B rests on several beams 12. More particularly, each crosspiece 32B is arranged in the interval "I" reserved between two longitudinal members 32A of each beam 12. Thus, the crosspieces 32B are located in the same horizontal plane as the longitudinal members 32A. The lower fixing face 34 of each crosspiece 32B is arranged directly in contact with the upper face 14 of each beam 12.

[0072] The crosspieces 32B are preferably fixed to the beams 12 by screwing or nailing. Alternatively, the crosspieces are fixed to the beams by gluing.

[0073] This grid arrangement of the side members 32A and the cross members 32B thus makes it possible to provide good support to the slab 24. This at least makes it possible to reduce the section of the metal rods used to form the frame 30.

[0074] As represented in the figure 2 , the floor 10 may also comprise interjoists 46 which are inserted into the spacing "E" between two beams 12. In this case, the beams 12 are also equipped with means for supporting the interjoists 46. This is a wooden board 48 fixed flat under the lower face 16 of each beam 12. The board 48 has a width greater than that of the beam 12 so that two lateral strips 50 of the board 48 protrude laterally on either side of the beam 12 to serve as support for the interjoists 46. Each board 48 is fixed to the beam 12, for example by gluing if it mechanically participates in the longitudinal behavior, by nailing or by screwing. The board 48 may be made of hardwood or softwood depending on the desired strength.

[0075] Such a floor 10 can be implemented either directly on the building site or in the workshop so that it can then be transported and installed as a prefabricated element on the site.

[0076] Regardless of the method of implementing the floor 10, the beams 12 are each previously equipped with one or more side members 32B. Thus, each side member 32B is fixed to the upper face 14 of each beam 12. As explained previously, the side members 32A are, for example, glued by their lower fixing face 34 to the upper face 14 of the associated beam 12.

[0077] When necessary, the board 48 is positioned and fixed against the lower face 16 of the beam 12. This gives the structural element shown in figure 15 .

[0078] Each spar 32A is then treated against moisture, for example by spraying with a water-repellent product. This treatment, carried out after fixing the spars 32A to the beam 12, makes it possible to obtain good sealing, including on the areas of the upper face 14 of the beam which would not be covered by a spar 32A, in particular in the spacings "I" between two spars 32A where applicable.

[0079] From these beams 12 thus produced, several ways of obtaining a floor according to the teachings of the invention are now described, without limitation.

[0080] According to a first embodiment described with reference to figures 1 And 16, when the floor 10 is intended to be made in the workshop, the beams 12 are arranged in parallel with a determined lateral spacing "E", for example approximately 60 cm. Then a formwork 52 is arranged between the beams 12 so that the upper face of the formwork is flush with the upper face 14 of the beams 12. The side members 32A thus project vertically upwards relative to the formwork 52.

[0081] Optionally, cross members 32B are arranged across the beams and fixed to the beams 12.

[0082] A metal reinforcement 30 is then placed on the beams 12 and on the side members 32A. Then the concrete slab 24 is poured on the formwork 52 and on the beams 12, so that the reinforcement 30 and the side members 32A, and where appropriate the sleepers 32B, are set in the concrete.

[0083] When the concrete has hardened, the formwork 52 is removed, and the floor 10, as shown in figure 1 , is transported to the construction site as a prefabricated element.

[0084] According to a second embodiment shown in the figure 17 , when the floor 10 is intended to be made in a workshop, it can be made in an inverted manner. The concrete slab 24 is then poured into a mold 54, the bottom of which forms the imprint of the upper face 26 of the slab 24, and in which the reinforcement 30 has been previously placed. The direction of gravity is indicated by the arrow "g".

[0085] Before the concrete hardens, the beams 12 are turned over, upper face 14 downwards, and then placed above the concrete slab 24 with their upper face flush with the surface of the poured concrete so that the stringers 32A, and if necessary the sleepers 32B, can be dipped into the still liquid concrete. The beams 12 are held in this position until the concrete has hardened.

[0086] When the concrete has hardened, the slab 24 can be demolded, the stringers 32A and the sleepers 32B then being set in the concrete. The floor 10 can be turned right side up.

[0087] Before being positioned above the slab 24, the beams are possibly connected to each other by crosspieces 32B.

[0088] This embodiment advantageously makes it possible to obtain a slab 24 having an upper face 26 having an excellent finish and very good flatness.

[0089] According to a third embodiment of the invention, when the floor 10 is made directly on the construction site. The beams 12 are then transported individually to the construction site.

[0090] Advantageously, to protect them during their transport, it is planned to provide the beams 12 with two skirts 56 made from a sheet of impermeable material such as flexible plastic, as illustrated in figure 18 . Each skirt 56 is arranged so as to cover an associated lateral face 18 of the beam. The upper face 14 is in fact protected by the side members 32A and by the water-repellent treatment, while the lower face 16 is protected by the boards 48.

[0091] The skirts 56 are fixed to their beam 12 by a free longitudinal upper edge 58 which extends along the angle between the upper face 14 and the associated lateral face 18. For transport, a lower edge 60 of the skirts is fixed along the board 48.

[0092] Advantageously, the protective skirts 56 can also be used to create formwork for the concrete slab 24 as will be explained later.

[0093] Once they arrive on site, the beams 12 are positioned in the structure, then they are fixed in place, as shown in figure 19 . The skirts 56 are raised, then interjoists 46 intended to form a formwork are arranged in the spaces "E" reserved between two adjacent beams. The interjoists 46 rest on the strips 50 of boards 48 which protrude from the two beams 12 on either side of the space "E".

[0094] To produce the slab 24, the skirts 56 are then folded flat onto the upper surface of the interjoists 46 and fixed edge to edge, for example by adhesive strips, to produce a waterproof horizontal surface 62 which is flush with the upper face 14 of the beams 12 for the purpose of pouring the slab, as illustrated in figure 20 . If necessary, crosspieces 32B are then arranged across the beams 12, over the horizontal waterproof surface 62, then fixed to the beams 12, as illustrated in figure 21 .

[0095] A reinforcement 30 is then placed on the beams thus arranged. The slab 24 can then be poured so that the reinforcement 30, the side members 32A and / or the cross members 32B are set in the concrete to obtain a floor 10 as shown in figure 2 .

[0096] The floor 10 produced according to any of the embodiments of the invention advantageously makes it possible to replace concrete and steel elements with wooden elements. This makes it possible both to limit the carbon footprint of the floor and to avoid having intensive recourse to non-renewable raw materials.

[0097] Furthermore, the floor 10 thus produced is easy to implement and has mechanical properties that are perfectly suited to the construction of buildings.

Claims

1. Concrete floor (10) comprising at least one beam (12) having a main axis (X), a concrete slab (24) which is cast so as to rest on an upper face (14) of the beam (12), a metal reinforcement (30) which is set in the slab (24), the beam (12) being connected to the concrete slab (24) by at least one inserted connecting element which is fastened to the beam (12) and at least a portion of which is set in the concrete slab (24), the beam (12) and the connecting element being made of wood, the connecting element being formed of a wooden strip (32) which extends along a main longitudinal axis (L) and which has a lower face (34) for fastening with the beam (12) and an upper face (36) for contact with the concrete slab (24), the concrete floor being characterised in that the wooden strip (32) comprises cavities (39) produced by removing material in its upper face (36) in which the concrete of the slab (24) is cast, the mainly transverse walls (40) delimiting the cavities (39) being capable of transmitting shearing forces (C) exerted mainly longitudinally by the slab (24) on the wooden strip (32) during a bending of the floor (10).

2. Floor (10) according to the preceding claim, characterised in that the cavities (39) are formed by grooves which extend mainly transversally.

3. Floor (10) according to the preceding claim, characterised in that the wooden strip (32) is delimited by at least two edges (38) which are provided with means for resisting the vertical pullout of the slab (24) with respect to the wooden strip (32).

4. Floor (10) according to the preceding claim, characterised in that the means for resisting the pullout are formed by ridges (42) which extend longitudinally and in which the concrete of the slab (24) is cast.

5. Floor (10) according to claim 3, characterised in that the means for resisting the pullout are formed by a beveled edge (38) shape.

6. Floor according to any one of claims 1 to 3, characterised in that the beam is made of softwood, while the wooden strip is made of hardwood.

7. Floor according to any one of claims 1 to 6, characterised in that the wooden strip (32) is fastened by bonding of its lower face (34) for fastening on the upper face (14) of the beam (12).

8. Floor (10) according to the preceding claim, characterised in that the lower face (34) for fastening the wooden strip (32) comprises longitudinal discharge slots (44) which make it possible to absorb the dimensional variations of the beam (12) according to hygrometric conditions.

9. Floor (10) according to any one of claims 1 to 6, characterised in that the wooden strip (32) is fastened to the beam (12) by screwing or by nailing.

10. Floor (10) according to any one of claims 1 to 9, characterised in that it comprises at least one wooden strip (32), the main longitudinal axis (L) of which extends parallel to the main axis (X) of the beams (12), called stringer (32A).

11. Floor (10) according to the preceding claim, characterised in that at least one beam (12) comprises a stringer (32A) which extends substantially over the entire length of the upper face (14) of the section of the beam (12) intended to receive the concrete slab (24).

12. Floor (10) according to claim 10, characterised in that at least one beam (12) comprises several stringers (32A) which are distributed aligned over the entire length of the upper face (14) of the beam (12) intended to receive the concrete slab (24).

13. Floor (10) according to the preceding claim, characterised in that it comprises: - at least two beams (12), each equipped with several stringers (32A) spaced apart longitudinally by an interval (I), - at least one wooden strip (32), the main longitudinal axis (L) of which extends along a direction orthogonal to the main axis (X) of the beams (12), called crossmember (32B), and fastened on the face (14) of each of the beams (12) in the interval (I) between two stringers (32A).

14. Floor (10) according to any one of claims 1 to 13, characterised in that the wooden strips (32) are treated with a waterproof product.

15. Method for producing a floor (10) according to any one of the preceding claims, characterised in that it consists of: - fastening at least one wooden strip (32) on the upper face (14) of each beam (12); - arranging a casing (52) and / or insulation (46) an upper face of which is flush with the upper face (14) of the beams (12), such that the wooden strips (32) project with respect to the casing (52) and / or to the insulation (46); - arranging a metal reinforcement (30) on the beams (12); - casting a concrete slab (24) which takes the metal reinforcement (30) and the wooden strips (32).