Construction of lightweight concrete elements

Abstract

The present invention relates to a system for holding (1) at least one box (2) relative to a support (6) intended to receive a layer of liquid material, the system comprising: - at least one pad (8) configured to be fixed to the support (6), - a rod (12) having a first elongated part (14) and a second fixing part (18) connected to the first part (14), the first part being configured to extend vertically relative to the support (6), the first part (14) further having a first free end (12a) configured to be inserted into the pad (8), the second fixing part (18) of the rod being configured to be assembled with a first portion of the box, the pad (8) being configured such that the insertion of the first free end (12a) into the first pad (8) allows adjustment of the length of the first part (14) of the rod (12) which extends between the pad (8) and the second fixing part (18),the second fixing part (18) being configured to prevent the lifting of the caisson (2) during the pouring of the liquid. Figure for the abbreviation: Fig. 4a,

Description

Title of the invention: Construction of lightweight concrete elements FIELD OF INVENTION

[0001] The invention relates to the construction of concrete elements, in particular slabs or walls. STATE OF THE ART

[0002] In constructions, concrete elements such as slabs, partitions or walls, foundations or bridge piers, generally include a set of metal reinforcements forming a reinforcement around which concrete is poured.

[0003] In order to reduce the carbon footprint of buildings, efforts have been made to decrease the amount of concrete used in construction without compromising structural integrity. To this end, processes and systems have been developed to integrate lightweight panels into slabs and / or partitions to replace some of the concrete. These panels are generally hollow or made of polyurethane foam, thus further reducing the weight of the buildings.

[0004] However, due to the lightness of these panels, and in particular their lower density compared to concrete, the manufacturing process for the slabs and partitions had to be adapted. For example, in the case of slab manufacturing, liquid concrete is poured onto a leveling concrete slab or a substrate intended to be removed once the concrete has hardened. If the panels are not secured to the leveling concrete slab or the substrate, they will lift and move under the effect of buoyancy. However, in order to comply with building codes, these panels must be positioned at a specific angle relative to the leveling concrete slab or the substrate and held in that position.

[0005] One way to prevent the caissons from moving during the concrete pour is to use caissons with feet and to carry out the pour in two stages. Specifically, a first layer of concrete, sufficient to surround the feet of the caissons but not high enough to lift them, is poured. Once this first layer has set and the feet and / or part of the caissons are held in place, a second layer of concrete, encasing the caissons and forming the slab of the desired thickness, is then poured.

[0006] This method makes it possible to form lightweight concrete slabs by reducing the amount of concrete used, without resorting to fastening systems. However, it is necessary to pour the concrete in two stages.

[0007] Another method used is to position a first layer of reinforcement, place the caissons on top, and then position a second layer of reinforcement on top The caissons and fixing the caissons to the reinforcement. However, according to this method, the benefit obtained by reducing the concrete is offset by the increase in the amount of reinforcement.

[0008] There is therefore a need to improve the manufacturing of concrete slabs in order to reduce their environmental impact and also to lighten construction. Description of the invention

[0009] The invention thus aims to produce concrete slabs having the required strength while reducing the amount of concrete used.

[0010] The invention also aims to optimize the manufacturing process of concrete slabs, and in particular the speed and ease of manufacturing.

[0011] The invention also aims to limit the amount of reinforcement used in the manufacture of concrete slabs.

[0012] The invention thus relates to a system for holding at least one container in relation to a support intended to receive a layer of liquid material, the system comprising: - at least one mounting point configured to be fixed to the support, - a rod comprising a first elongated part and a second fixing part connected to the first part, the first part being configured to extend vertically relative to the support, the first part further comprising a first free end configured to be inserted into the block, the second fixing part of the rod being configured to be assembled with a first portion of the box, the block being configured so that the insertion of the first free end into the first block allows the length of the first part of the rod which extends between the block and the second fixing part to be adjusted, the second fixing part being configured to prevent the lifting of the box during the pouring of the liquid.

[0013] This system allows one or more caissons to be held in place relative to a support, thus limiting their movement during the pouring of concrete onto the support. This system is simple and easy to use, allowing the concrete to be poured in a single operation. Adjusting the length of the first part of the rod allows the caisson to be positioned at the desired height relative to the support. Indeed, during the concrete pour, the caisson will be lifted to the limit of the length of the first rod extending between the base and the second fixing part.

[0014] According to one possible embodiment, the second fastening part may be a part extending in a direction different from the longitudinal axis of the first part. The second part may then form an elbow, a hook, or any other shape allowing the second part to form a non-zero angle other than 180° with the Part one. According to this embodiment, the second part secures the first section of the housing relative to the rod. The first section of the housing may, for example, include an opening into which the first section of the rod can be inserted and then pushed to slide until it reaches a locking position when the second section reaches the opening, through which it cannot slide.

[0015] According to another possible embodiment, the second part may include a fastening device configured to be attached to the first portion of the box. The first portion of the box may include a complementary fastening device configured to cooperate with the second part.

[0016] According to one possible embodiment, the two embodiments below can be combined.

[0017] The boxes preferably have a rectangular prism shape but can also have other shapes.

[0018] Moreover, the first elongated part is preferably straight.

[0019] According to one possible embodiment, the system may comprise: - a first and a second pedestal configured to be fixed to a support, - a rod comprising a first part, a second part and a third part, the first and second parts being configured to extend vertically from the support and being connected to each other by means of the third part, the first and second parts further comprising respectively a first free end and a second free end configured to be inserted respectively into the first and second studs, the first part of the rod being configured to be connected to a first section of the casing and the second part being configured to be connected to a second section of the casing, the first and second pads being configured so that the insertion of the first free end and the second free end into the first and second pads respectively allows the length of each of the first and second parts of the rod which extends between each pad and the third part to be adjusted, the third fixing part being configured to prevent the lifting of the box during the pouring of the liquid.

[0020] According to this embodiment, the second stud is identical to the first stud and the first part of the rod is identical to the second part of the rod.

[0021] The first portion and the second portion may belong to the same box or to two different boxes. According to a preferred embodiment, the first portion belongs to a first box and the second portion belongs to a second box. The rod, and in particular the third rod portion, then makes it possible to maintain the first and second boxes at a predefined distance from each other. According to this embodiment In terms of implementation, it is possible to form a network of boxes on the support, each box being preferably connected to two other boxes by means of one or two support systems.

[0022] According to one possible embodiment, the first and second portions may belong to the same box. The first block may then be positioned at one end of one face of the box and the second block at the other end of the same face of the box. A box in the shape of a rectangular prism can then be held by means of two retaining systems, and several boxes can thus be positioned on the support.

[0023] The caissons have a lower density than concrete, in particular a density of less than 2.2 g / cm³, and preferably less than 1 g / cm³, in order to lighten the concrete structure in which they are used. The density of the caissons is, in particular, an overall density, with some parts of the caisson having a higher density than other parts. For example, the caissons may have an outer casing forming an interior space, the casing preferably being made of plastic and the interior being empty or filled with a lightweight polymer such as polyurethane foam. The caisson is preferably in the overall shape of a rectangular prism but may also have other shapes.

[0024] According to particular embodiments which may be taken alone or in combination: - the block includes a connecting part having a hollow configured to receive the free end, the connecting part being configured so that the free end can be inserted at a plurality of possible depths so as to adjust the length of the first part of the rod which extends between the first block and the second fixing part; the system thus makes it possible to choose the length of rod which is not inserted in the block and therefore the maximum height to which the box can rise relative to the support when the concrete is poured onto the support; - according to the embodiment in which the system comprises a first and a second stud, the first stud comprises a first connecting part having a first hollow and the second stud comprises a second connecting part having a second hollow, the first and second hollow being configured to receive respectively the first and second ends, the first and second ends being able to be inserted into the first and second connecting parts at a plurality of possible depths so as to adjust the length of the first and second parts of the rod which extend respectively between the first stud and the third part and the second stud and the third part; - the first free end is fixed in the hollow by means of a fastening device or fastening assembly; the first free end is then inserted in the hollow at a chosen depth, then is fixed by the fixing device or embedded in the fixing composition; the fixing device may, for example, include one or more pressure screws or a wedge system; the fixing composition is, for example, an adhesive, for example an epoxy adhesive, or a resin; - the pedestal has a base configured to be fixed to the support, the connecting part being positioned in line with the base; the base and the connecting part can be made of the same material or of different materials; the base and the pedestal can, for example, both be made of concrete or polymer, or the base can be made of concrete and the connecting part of polymer; the orifice can extend only in the connecting part or in the connecting part and in a part of the base; - according to the embodiment in which the system comprises a first and a second pad, the first and second pads respectively comprise a first base and a second base configured to be fixed to the support, the first connecting part and the second connecting parts being positioned respectively in the extension of the first and second base; - the base is configured to be glued to the support and / or held to the support by means of a fixing device cooperating with the base and the support; the fixing device may, for example, be inserted into the base; the fixing device may, for example, be a screw screwed into the base, the screw being able to pass through the support or emerge from the face of the support which is in contact with the stud; - the second rod fixing part is configured to prevent the movement of at least one caisson away from the support; in particular, the second part forms a non-zero angle other than 180° with the first rod part so that, when the caisson is lifted by the concrete being poured onto the support, the caisson cannot exceed a certain height relative to the support; in the embodiment in which the system comprises two pads, the third part may be curved or straight; preferably, the third part is straight and thus forms a 90° angle with the first and second rod parts; the third part then extends in a direction parallel to the support; and - the first part of the rod is configured to be able to slide into at least one through hole in the first portion of the box.

[0025] In the previously described retaining system, the stud can be a first stud and the rod can be a first rod and the system can further comprise a second stud identical to the first stud and a second rod identical to the first rod, the first and second rods being connected to each other by their respective second parts.

[0026] The invention also relates to a support structure comprising at least one support system as previously described, as well as a support on which the stud, or the first and second studs, are fixed, and at least one box.

[0027] The support structure preferably comprises a plurality of support systems and a plurality of boxes. According to the embodiment comprising a first and a second support, each support system can be arranged so as to be assembled to two portions belonging to two different boxes or to two portions belonging to the same box.

[0028] The support structure may further include at least one wedge positioned between the support and the first portion of the box, the wedge being configured to maintain the first portion of the box at a predefined distance from the support.

[0029] The invention also relates to a method for constructing a concrete element comprising at least one caisson having a density lower than that of concrete by means of the support system or support structure as previously described, the method comprising the following steps: - a step El of positioning at least one stud on a support, - an E2 step of assembling the first part of the rod to the first portion of the casing, - a step E3 of inserting the first free end into the block so as to adjust the length of the first part of the rod which extends between the block and the second fixing part, - a step E4 of immobilizing the first free end in the block, - a step E5 of fixing the stud to the support, and - a step E6 of pouring concrete onto the support so as to immerse at least part of the caisson.

[0030] The method allows for the positioning of at least one support system and the caisson on the support, followed by pouring the concrete onto the support in a single operation. During the concrete pour, the support is placed in a horizontal position. Since the caisson is held in place by the support device, it will remain in the desired position after all the concrete forming the element has been poured. In particular, the caissons will float on the concrete, which has a higher density than the caissons, but will be held laterally by the first and second rod sections. When the concrete lifts the caisson under the effect of Archimedes' principle, the caisson will not exceed a maximum height relative to the support because it will be held in place by the second rod section. Thus, the caisson will have limited mobility during the concrete pour and will then be fixed at a maximum height once the concrete has been poured.

[0031] According to the embodiment comprising a first and a second plot, the process may comprise the following steps: - a step El of positioning at least one first and a second marker on a support, - a step E2 consisting of connecting the first part of the rod to the first portion of the box and the second part of the rod to the second portion of the box, - a step E3 of inserting the first end into the first block and the second end into the second block so as to adjust the length of the first and second parts of the rod which extends between the block and the third part, - a step E4 of immobilizing the first end in the first block and the second end in the second block, - a step E5 of fixing the first and second studs onto the support, and - a step E6 of pouring concrete onto the support so as to immerse at least part of at least one caisson.

[0032] The method may further include a step Ea of positioning at least one wedge under each portion of the box, the wedge allowing the box to be positioned at the desired height relative to the support.

[0033] The invention also relates to a concrete element comprising at least one retaining system or at least one retaining structure as previously described or obtained according to the previously described process, the retaining system or retaining structure being embedded in concrete.

[0034] The concrete element can be, for example, a slab, a partition, a wall, a foundation or a bridge pier. DESCRIPTION OF THE FIGURES

[0035] Other features and advantages of the invention will become apparent from the following description, given solely by way of example and with reference to the accompanying drawings, in which:

[0036] [Fig.1] represents a schematic side view of a holding system according to a first embodiment of the invention;

[0037] [Fig. 2a] represents a schematic side front view of a rod end inserted into a plot according to a variant of the embodiment;

[0038] [Fig. 2b] represents a schematic side front view of a rod end inserted into a plot according to another embodiment variant;

[0039] [Fig.3] represents a schematic top view of a retaining structure according to the invention;

[0040] [Fig.4a] represents a side view of a retaining system according to a second method of implementing the invention;

[0041] [Fig.4b] represents a side view of a retaining system according to a third method of implementing the invention;

[0042] [Fig.5] represents a flowchart showing the steps of a manufacturing process of a concrete element according to an embodiment of the invention;

[0043] [Fig.6] represents a cross-sectional view of a concrete slab comprising the system of maintenance of [Fig. 1]; and

[0044] [Fig.7] represents a cross-sectional view of a concrete slab comprising the system of maintenance of [Fig.1]. DETAILED DESCRIPTION OF THE INVENTION

[0045] For the sake of clarity, only the essential elements for understanding the invention have been represented schematically, without regard to scale. Furthermore, when the terms "upper," "lower," "above," "below," and others are used, they refer to the support structure in a functional position, i.e., when the support is in a horizontal position and the support structure is positioned on the support.

[0046] According to a first embodiment of the invention shown in [Fig.1], a system for holding 1 of a first box 2 and a second box 4 relative to a support 6 comprises a first stud 8 and a second stud 10 connected to each other by a rod 12.

[0047] The first stud 8 and the second pot 10 are configured to be fixed to the support 6.

[0048] The rod 12 comprises a first part 14, a second part 16 and a third part 18. The first part 14 and the second part 16 extend in a vertical direction relative to the support 6 and are connected to each other by means of the third part 18.

[0049] The first part 14 has a first free end 14a intended to be inserted into the first stud 8. Similarly, the second part 16 has a second free end 16a intended to be inserted into the second stud 10. Furthermore, the first part 14 of the rod 12 is connected to a first portion of the box 2 and the second part 16 of the rod 12 is connected to a second portion of the box 4.

[0050] The first and second boxes 2 and 4 each comprise an upper through hole 28a and a lower through hole 28b emerging from their wall, the through axis of which is parallel to a longitudinal axis of the box and perpendicular to the support when the box is placed on the support. During the installation of the retaining system 1, the first and second parts 14 and 16 are inserted into the holes 28 by their respective free ends 14a and 16a, then slide into the two holes 28, and are subsequently inserted into the first and second studs 8 and 10.

[0051] In this embodiment, before the concrete is poured onto the support 6 and before the free ends 14a and 16a are fixed in the first and second blocks 8 and 10 respectively, the boxes 2 and 4 can slide along the rod and are not fixed to it. The retaining system 1 is thus simple and easy to assemble with the boxes.

[0052] In this embodiment, each box 2 and 4 is a set of two boxes, in particular a lower box 2a (4a) and an upper box 2b (4b). The first part 14 of rod 12 is thus connected to the lower box 2a by one of the two holes 28 and to the upper box 2b by the other of the two holes 28, and the second part 16 of rod 12 is connected to the lower box 4a by one of the two holes 28 and to the upper box 4b by the other of the two holes 28.

[0053] In this embodiment, the boxes 2 and 4 are formed by a polymer shell enclosing an interior space containing only air, the overall density of the box being 0.1 g / cm³. According to possible embodiments, the box shell may be made of concrete or cardboard, and the interior may be filled with a lightweight polymer such as polystyrene. The box may also be a single-piece polymer box, for example made of polystyrene, without a shell.

[0054] The first stud 8 and the second stud 10 are configured such that inserting the first free end 14a and the second free end 16a into the first and second studs 8 and 10 respectively allows the length of the first rod portion 14 and the second rod portion 16 to be adjusted. The length of each rod portion corresponds to the distance between each stud and the third portion, also called the free section of the rod. In particular, it is the distance between the first stud 8, specifically the free end of the stud opposite an end attached to the support, and a first junction 18a between the first rod portion 14 12 and the third rod portion 18, and the distance between the second stud 10, specifically the free end of the stud opposite an end attached to the support, and a second junction 18b between the second rod portion 16 12 and the third rod portion 18 12.

[0055] The free end of the studs corresponds to the end through which the free end of the rod is inserted and the fixing end to the support of the studs 8 and 10 corresponds to the end in contact with the support when the studs are put in place on the support.

[0056] The holding system 1 thus makes it possible to hold the first and second boxes 2 and 4 relative to the support 6 in an initial position.

[0057] According to a variant of the first embodiment, the initial position of the caissons can evolve towards a final position when concrete is poured onto the support.

[0058] According to this embodiment, the boxes 2 and 4 are placed on the support or on another element in an initial position, then the first part 14 and the second part 16 of the rod 12 are inserted into the upper holes 28a and lower holes 28b and finally into the studs 8 and 10 respectively. The gap between the first and second boxes 2 and 4 is fixed and corresponds to the gap between the first part 14 of the rod 12 and the second part 16 of the rod 12 and therefore, in this embodiment, to the length of the third portion.

[0059] In contrast, still according to this variant, in the initial position, the first and second caissons 2 and 4 have vertical movement possibilities, but these are limited to sliding along the first and second sections 14 and 16 of the rod 12 until they reach a blocking point when the upper holes 28a abut against the third section 18 of the rod 12. When concrete is poured onto the support 6, the first and second caissons 2 and 4, which have a lower density than the concrete, will rise along the first and second sections 14 and 16 respectively, up to a maximum height. The maximum height is reached when the upper holes 28a reach the first and second junctions 18a and 18b respectively.

[0060] The third part 18 of the rod 12 thus makes it possible to block the movement of the first and second caissons 2 and 4 in their translational movement along respectively the first part 14 of the rod 12 and the second part 16 of the rod 12 away from the support 6, in particular when the concrete is poured onto the support 6.

[0061] According to another variant of the second embodiment, the final height of the first box 2 and the second box 4 is fixed by means of a first wedge 32 and a second wedge 34. According to this variant of the embodiment, when the rod 12 is inserted into the upper and lower holes 28a and 28b, it is pushed in until the upper holes 28a come against the third part 18.

[0062] In the first embodiment, the third part 18 extends in a direction perpendicular to the longitudinal axis of the first and second parts 14 and 16. According to possible embodiment variants, the third part 18 may not be straight and may form a non-zero angle with the first and second parts 14 and 16. The third part 18 may, for example, be curved.

[0063] As shown in Figures 2a and 2b, the first stud 8 has a first connecting portion 20 which has a first recess 21 with a depth that allows the first end 14a to be inserted at several possible depths. In this way, the length of the free section of the first portion 14 of the rod 12 can be adjusted. Similarly, the second end 16a is inserted into a second connecting portion 22 of the second stud 10. The length of the free section of the second portion 16 of the rod 12 can also be adjusted.

[0064] Preferably, the first and second free ends 14a and 16a are inserted respectively into the first and second connecting parts 20 and 22 so that the length of the free section of the first part 14 of rod 12 is equal to the length of the free section of the second part 16 of rod 12.

[0065] According to the first embodiment described above, the first and second parts 12 and 14 can be positioned at the desired depth in the first and second connecting parts 20 and 22 respectively.

[0066] In contrast, according to the second embodiment described above, the insertion depth of the first and second parts 12 and 14 in the first and second connecting parts 20 and 22 respectively is determined by the height of the first and second wedges 32 and 34, which defines the height of the upper holes 28a that lock the third part 18. Thus, when the rod 12 is put in place, the first and second ends 12a and 14a are inserted into the upper holes 28a and lower holes 28b of the boxes and then into the recesses of the first and second connecting parts 20 and 22. The rod 12 is then locked when the upper holes 28a abut against the third part 18 and the free ends 12a and 12b are inserted into the corresponding recesses of the blocks, but without abutting the bottom of the recesses. On the contrary, the free ends are spaced from the bottom of the hollows as shown in [Fig.2a].

[0067] This embodiment is particularly advantageous when the type of concrete element requires a cover layer in which no metal elements are to be positioned. The cover layer is a protective zone, or a minimum thickness on the substrate, which must consist only of concrete and, in particular, must not contain any metal. In this embodiment, the pads 8 and 10 and the shims 32 and 34 are made of concrete, and the height of the shims is chosen so that the free ends 12a and 14a do not reach the cover layer. According to this embodiment variant, it is even possible to position reinforcement on the first and second wedges 32 and 34 so that it is above the cover layer, then to position the first and second caissons 2 and 4 on the reinforcement, and finally to position the rod 12 so that the free ends 12a and 14a do not reach the cover layer.

[0068] In this embodiment, the first and second free ends 14a and 16a are fixed respectively in the recess of the first and second connecting parts 20 and 22 by means of a fixing composition which may be an adhesive (for example, polyurethane), a resin (for example, an epoxy resin), a sealant, a cement, or something similar. The first and second free ends 14a and 16a are thus inserted to the desired depth and then embedded in the fixing composition.

[0069] According to other possible embodiments, the fixing of each free end in the connecting parts of the studs can be done by means of a mechanical fixing device such as, for example, a rod perpendicular to the axis of the rod and which is inserted into an orifice in the rod, notches positioned in the connecting parts and allowing the rod to be locked, one or more pressure screws, or even a wedge system.

[0070] The first and second pads 8 and 10 further comprise, respectively, a first base 24 and a second base 26, which are configured to be fixed to the support 6. The first and second connecting portions 20 and 22 are positioned in line with the first and second bases 24 and 26, respectively, opposite the support 6. In this embodiment, the first and second bases 24 and 26 are conical in shape, the wider part of the cone being positioned in contact with the support 6 and the narrower part of the cone being extended by the first and second connecting portions 20 and 22, respectively. However, the base may have other shapes and, in particular, a round, oval, square, or triangular cross-section, the cross-section being of constant or non-constant dimensions along the height of the base.

[0071] For each stud, the base and the connecting part can be made of the same material or of a different material.

[0072] According to a preferred embodiment, the base and the connecting part are made of different materials, the base being made of concrete, in particular B40 concrete, and the connecting part being made of a polymer material, in particular polylactic acid (PLA), nylon, or other. The base and the connecting part may also be made of other materials.

[0073] According to other possible embodiments, the base and the connecting part can be formed from the same material, such as both being made of polymer material or both being made of concrete. The base and the connecting part can then be two separate parts or form a single-piece block.

[0074] The hollows into which each free end 14a and 16a are inserted can extend only in the connecting part or extend in the connecting part and in the base.

[0075] According to a first embodiment of the pads shown in [Fig. 2a], the base 24 or 26 can be bonded to the substrate using a fixing compound such as an adhesive (e.g., polyurethane), a resin (e.g., epoxy resin), a sealant, or cement. This embodiment may be preferred when the substrate 6 is a layer of screed or leveling concrete formed directly on the ground and the underside of the substrate 6, i.e., the side opposite the one onto which the concrete is poured, is not accessible.

[0076] According to a second possible embodiment of the pads shown in [Fig. 2b], the pads 8 and 10, and in particular their bases 24 and 26, can be fixed to the support by a fastening device T1. The fastening device 27 can, for example, be a screw passing through the support and screwed into a threaded hole in the base. This embodiment allows the support to be removed once the concrete has been poured and hardened by removing the fastening devices. The fastening device can also be a non-through screw emerging from the support 6 to which the base is screwed.

[0077] Figure 3 shows a support structure 30 comprising four support systems 1 and the support 6, the four support systems holding four boxes 2, 4, 2', and 4'. The boxes that are side by side are connected in pairs by two support systems positioned between the two front corners and the two rear corners of the facing boxes. Each of the four boxes could be connected to another box from the face opposite the one already connected by two support systems 1. The boxes could also be connected by positioning the support systems between two front and rear boxes, for example, between box 2 and box 4 on the one hand, and between box 2' and 4' on the other. It is also possible to position some of the support systems between two side-by-side boxes and other parts of the support systems between two front and rear boxes.

[0078] According to one possible embodiment, the support system 1 can be assembled with a single box so as to span it. According to this embodiment, the first portion can be a first face of the box, the second portion a second face of the box, and the third portion of the rod 18 can extend over the upper surface of the box so as to prevent it from lifting during the pouring of concrete onto the support.

[0079] As can be seen in [Fig. 1], the support structure can further include a first wedge 32 and a second wedge 34, the first wedge 32 being positioned between the support 6 and the first caisson 2 and the second wedge being positioned between the support 6 and the second caisson 4. The first and second wedges 32 and 34 make it possible to maintain the first and second caissons 2 and 4 at a predetermined height relative to the support 6, before pouring the concrete onto the support.

[0080] According to a second possible embodiment shown in [Fig. 4a], the retaining system 1 may comprise only a stud 8 and a rod 12. The rod 12 then comprises a first elongated portion 14 which is straight and a second fixing portion 18. This embodiment differs from the first embodiment only in that the third portion 18 forms a hook configured to abut against the upper hole 28a. The stud 8, the housing 2, and the other elements of the retaining system are as previously described for the first embodiment.

[0081] According to a third embodiment shown in [Fig.4b], the retaining system 1 comprises a single rod 12 and a single stud 8 as in the second embodiment, but the rod 12 is positioned in a central position of the box 2. For this purpose, the box 2 comprises a central through conduit 19 inside which the rod 12 is positioned.

[0082] The rod 12 then includes a second fixing portion 18 which cooperates with a complementary fixing device 17 of the box 2 to fix the rod 12 to the box 2. The pad, the shims, and the other elements are such as those described for the first embodiment. The second fixing portion 18 can also be a straight portion extending in a direction perpendicular to the first portion, forming a T-shaped rod, the second fixing portion 18 extending over an upper surface of the box in order to prevent any vertical movement of the box during the pouring of the concrete.

[0083] A method 40 for manufacturing a concrete slab is now described with reference to [Fig. 5]. The method is implemented using the support system 1 according to the first embodiment and comprises the following steps: - a step El of positioning the first block 8 and the second block 10 on the support 6; - a step Ea of positioning a first wedge 32 next to the first block 8 and a second wedge 34 next to the second block 10, so that each wedge is under the boxes which will be connected to the support system 1; - a step E2 of assembly of the first part 14 of the rod 12 to the first box 2 and of the second part 16 of the rod 12 to the second box; - a step E3 of inserting the first end 14a into the first block 8 and the second end 16a into the second block 10 so as to adjust the length of the first and second parts 14 and 16 of the rod 12 which extends between the block 8, 10 and the third part 18, and so that the first and second caissons are placed on the first wedge 32 and the second wedge 34; - a step E4 of immobilizing the first end 14a in the first stud 8 and the second end 16a in the second stud 10, in particular by means of an adhesive; - a step E5 of fixing the stud to the support, and - a step E6 of pouring concrete onto the support 6 so as to immerse the first and second caissons 2 and 4.

[0084] The concrete is thus poured in a single pour onto the support 6, and the caissons will float on the concrete, which has a higher density than the caissons, but will be held laterally by the first and second parts 14 and 16 of the rod 12. The boxes 2 and 4 will then be blocked when the holes 28 of the upper boxes 2b and 4b will butt against the third part 18 of the rod 12.

[0085] According to possible embodiments, the method may include placing reinforcement bars beneath the caissons. The reinforcement bars may be placed on spacers so as to be at a certain height relative to the support and thus respect the concrete cover layer, which must not contain reinforcement bars. The caissons may then be placed directly on the reinforcement bars or on additional spacers placed on the reinforcement bars. According to these embodiments, the supports are preferably high enough so that their upper end extends beyond the reinforcement bars and the free end of the rod is not located within the concrete cover zone.

[0086] Furthermore, step E5 can be carried out before or after step E2, between step E2 and step E3, between step E3 and step E4, or after step E4. Step Ea, which involves positioning the shims, can be carried out before step E2, between step E2 and step E3, or between step E3 and step E4.

[0087] Figure 6 shows a concrete slab 50 that can be obtained using the process described above with reference to Figure 5. Along its length, the slab comprises seven coffers 54 held together by six retaining systems 1 according to the first embodiment. Each coffer rests on a lower support 56 and has on its upper face an upper support 58 positioned between the upper face of the coffer and the upper reinforcement bed.

[0088] The slab also includes reinforcement allowing the slab to be anchored in the partitions 52.

[0089] The slab was thus easily manufactured by process 40 by pouring the concrete in a single pour. The support systems 1 made it possible to create a network of caissons 54 held laterally to one another and having limited mobility in the vertical direction before the concrete was poured, and zero mobility once the concrete was poured. In this embodiment, the lower shims 56 and upper shims 58 further limited the mobility of the caissons before the concrete was poured.

[0090] Figure 7 represents a portion of a concrete slab produced using method 40 with the support system 1 according to the second embodiment. The portion of the concrete slab 60 comprises a plurality of caissons 2, each supported by four support systems 1 arranged at each corner of the caissons 2. First wedges 35 are placed between the support and a reinforcement grid, and then second wedges 36 are placed between the reinforcement grid and the caissons 2.

[0091] Concrete slabs can thus be manufactured efficiently and using simple support systems. Furthermore, the support systems according to the invention make it possible to hold the caissons in place so that they cannot lifting beyond the desired height allows the concrete to be poured in one go, thus saving time during production.

[0092] Advantageously, the support system 1 can be chosen according to the concrete element to be manufactured, the need to have a coating layer or not, or the need to retain the support in the final element or not.

Claims

Demands

1. A system for retaining (1) at least one box (2) relative to a support (6) intended to receive a layer of liquid material, the system comprising: - at least one pad (8) configured to be fixed to the support (6), - a rod (12) having a first elongated portion (14) and a second fixing portion (18) connected to the first portion (14), the first portion being configured to extend vertically relative to the support (6), the first portion (14) further having a first free end (12a) configured to be inserted into the pad (8), the second fixing portion (18) of the rod being configured to be assembled with a first portion of the box, the pad (8) being configured such that the insertion of the first free end (12a) into the first pad (8) allows adjustment of the length of the first portion (14) of the rod (12) which extends between the pad (8) and the second fixing portion (18),the second fixing part (18) being configured to prevent the lifting of the casing (2) during the pouring of the liquid.

2. Retaining system (1) according to claim 1, wherein the stud (8) has a connecting part (20) having a hollow (21) configured to receive the first free end (12a), the connecting part (20) being configured so that the first free end (12a) can be inserted at a plurality of possible depths so as to adjust the length of the first part (14) of the rod (12) which extends between the first stud (8) and the second fixing part (18).

3. Retaining system (1) according to claim 2, wherein the first free end (12a) is fixed in the hollow (21) by means of a fixing device or a fixing composition.

4. Retaining system (1) according to claim 2 or 3, wherein the block (8) has a base (24) configured to be fixed to the support (6), the connecting part (20) being positioned in the extension of the base (24).

5. Retaining system (1) according to claim 4, wherein the base (24) is configured to be glued to the support (6) and / or held to the support (6) by means of a fastening device (27) cooperating with in the base (24) and the support (6).

6. Retaining system (1) according to any one of the preceding claims, wherein the second fixing part (18) of the rod (12) is configured to block the movement of at least one box (2) away from the support (6).

7. Retaining system (1) according to any one of the preceding claims, wherein the first rod portion (14) is configured to be able to slide in at least one through hole (28a, 28b) of the first portion of box.

8. A support system according to any one of the preceding claims, wherein the stud (8) is a first stud and the rod is a first rod (14), the system further comprising a second stud (10) identical to the first stud (8) and a second rod (16) identical to the first rod (14), the first and second rods being connected to each other by their respective second parts (18).

9. Support structure (1) comprising the support system according to any one of claims 1 to 8 and a support on which are fixed the block and / or the first and second block and at least one box.

10. Support structure (30) according to claim 9, further comprising at least one wedge (32, 34) positioned between the support (6) and the first portion of the box, the wedge (32, 34) being configured to maintain the first portion of the box at a predefined distance from the support (6).

11. A method (40) for constructing a concrete element comprising at least one caisson (2) having a density lower than that of concrete by means of the support system (1) according to any one of claims 1 to 8 or a support structure (30) according to claim 9 or 10, the method comprising the following steps: - a step E1 of positioning at least one block (8) on a support (6), - a step E2 of assembling the first part (14) of the rod (12) to the first portion of the caisson, - a step E3 of inserting the first free end (12a) into the block (8) so as to adjust the length of the first part (14) of the rod (12) which extends between the block (8) and the second fixing part (18),

12. - a step E4 of immobilizing the first free end (12a) in the block (8), - a step E5 of fixing the stud (8) onto the support (6), and - a step E6 of pouring concrete onto the support (6) so as to immerse at least part of the caisson (2). Concrete element comprising at least one retaining system (1) according to any one of claims 1 to 8, or at least one retaining structure (30) according to claim 9 or 10, or obtained according to the process (40) according to claim 11, the retaining system (1) or the retaining structure (30) being embedded in concrete.