Device for producing a perforated concrete structure having a multiple offset on the thickness, and method for producing such a structure

Abstract

The invention relates to a device and an associated method for producing a perforated concrete structure having a single or multiple offset on the thickness of the "3D mesh" (50), comprising a rigid mold block (10) which is made of machined polymer and comprises at least one molding plate (10a), said molding plate comprising reservations (12) having respectively a clearance of less than 10 degrees, all or part of the reservations (12) advantageously having an overthickness (15) on the upper surface.

Description

TECHNICAL FIELD OF THE INVENTION

[0001] The invention relates to a device for making an openwork concrete structure and a method for making such a structure. STATE OF THE ART

[0002] The openwork concrete structures, also referred to by the terminology concrete mesh, These structures are primarily intended for use as facade cladding or building elements. They are chosen mainly for their aesthetic qualities. For example, the Museum of European and Mediterranean Civilisations (MuCEM) incorporates this type of structure in certain parts of its building. Concrete grids are typically made with ultra-high-performance concrete, which gives the resulting structure exceptional durability and mechanical strength.

[0003] From a dimensional standpoint, concrete meshes are typically flat elements with varying degrees of perforation. The perforations are created by means of recesses in a mold base. Given the adhesion properties of concrete to the molding support, to facilitate the demolding of concrete resins, either removable recesses are used, allowing their removal before the part is demolded, or recesses are integral to the mold but, in this case, have a draft angle (or batter) greater than 5 degrees (generally around 10 degrees), or removable recesses with draft angles are used.

[0004] While draft angles facilitate demolding, they negatively impact the aesthetic appearance of the resulting structure. They can also make mold maintenance more difficult, as the mold can become clogged and subsequently affect the aesthetic quality of the finished structure.

[0005] Current equipment and processes do not allow the design of concrete grids with little or no draft at the level of the recesses for rigid molds.

[0006] Similarly, the removal of removable reservations remains difficult and it can happen that the molded structure is subjected to shocks or stresses which can generate areas of weakness and thus locally alter the resistance of the structure.

[0007] Concrete, moreover, is a material that exhibits potentially significant early-age shrinkage deformations, particularly depending on the volume of paste in the mix. The deformations prevented during the drying process due to the presence of the recesses can lead to a risk of cracking around the perimeter of the recesses.

[0008] The molds currently used to create concrete latticework are made of steel, wood, silicone, polyurethane, expanded plastic foam, as described in patent application FRFR2608963, or a mixture of these materials to allow for the design of the various mold parts. However, such molds have the major drawback of being either expensive or having a limited lifespan. Furthermore, some do not allow for the creation of structures with relief within the plane of the structure's thickness. Similarly, some molds, due to the nature of the materials from which they are made, have a limited reusability, not exceeding 500 units.

[0009] Document KR 101 888 335 B1 discloses a device for the realization of a multi-offset perforated concrete structure comprising a rigid machined polymer mold block including a first one-piece molding plate.

[0010] The invention aims to remedy these problems by proposing a device and an associated method for producing a resistant and durable openwork concrete structure (mesh) whose aesthetic quality has been controlled so as to be able to produce a structure adapted to the expected aesthetic criteria according to the type of application for which the structure is intended.

[0011] The device and associated method according to the invention also aims to create an openwork concrete structure with a relief in the plane of the thickness of the structure.

[0012] The invention also aims to provide a device for making an openwork concrete structure with improved resistance so that it can be reused a large number of times (i.e., making at least 500 pieces), offering easy demolding and reducing the risk of damage to the pieces during demolding. SUBJECT OF THE INVENTION

[0013] To this end, and according to a first aspect, the invention proposes a device for the realization of a perforated concrete structure with multiple offsets over the thickness according to claim 1.

[0014] According to the invention, the mold block comprises a first and a second molding plate, the first molding plate having recesses with a draft angle of less than 10 degrees. The two molding plates are arranged so that, when positioned in contact with each other along a vertical parting line, they form a closed lower end and an opening for pouring concrete between the molding plates. Once hardened, the structure is demolded by successive or simultaneous separation of the two molding plates. Alternatively, demolding by tilting onto a support is also possible when one of the molding plates has raised edges, the tilting of the molding plate with the raised edges being carried out after the other molding plate has been removed.

[0015] Advantageously, the remains are less than 5 degrees, and preferably are of the order of 3 degrees.

[0016] Advantageously, the mold block has removable formwork sides or forms that are one piece with the first molding plate.

[0017] Advantageously, the first molding plate is attached to a rigid support consisting of at least one plywood plate or a plate of the same nature as said first molding plate.

[0018] According to the invention, the first molding plate is a single piece.

[0019] Advantageously, the device includes means for generating agitation within the mold block.

[0020] Advantageously, the device includes means for reversing the support.

[0021] The invention also relates to a method for making an openwork concrete structure by means of a device as described above in claim 7.

[0022] According to the invention, the pouring operation consists of a vertical or inclined plane pouring operation of fresh concrete into the mold block formed by the first and second molding plates joined to each other through the opening made at the level of the molding plates.

[0023] Advantageously, the mold block is subjected to actions generating agitation within it during the pouring operation and / or during the demolding operation.

[0024] Advantageously, the process described above results in an openwork structure with multiple offsets over the thickness.

[0025] Advantageously, the process described above results in an openwork concrete railing.

[0026] It is of course clear that the invention is not limited to this application and that openwork structures can be made for other applications. By way of example, these can be used for facade cladding, wall coverings, sunshades, pool surrounds, stairwells, sliding gates, fences, bus shelters, and indoor and outdoor furniture.

[0027] The device and methods according to the invention just described make it possible to create an openwork concrete structure that presents a relief within the plane of the structure's thickness, while also being resistant, durable, and reusable. They also allow for control over the aesthetic quality of the resulting openwork structure.

[0028] The device according to the invention also has the advantage of facilitating demolding and simultaneously reducing the risks of damage to the parts during demolding, regardless of the casting operation carried out (vertical casting or in an inclined plane). BRIEF DESCRIPTION OF THE FIGURES

[0029] Other features and advantages of the invention will become apparent from the detailed description of the invention which follows with reference to the attached figures, in which: [ Fig. 1 ] There figure 1 represents a perspective view of part of a device for the construction of an openwork concrete structure by flat casting according to an unclaimed embodiment; Fig. 2 ] There figure 2 represents a front view of the mold of the figure 1 ; Fig. 3 ] There figure 3 represents a cross-sectional view along axis AA of the mold of the figure 2 ; Fig. 4 ] There figure 4represents a detailed view of the mold of the figure 3 ; Fig. 5 ] There figure 5 represents a view of the openwork concrete structure obtained with the mold of the figure 1 .

[0030] For clarity, identical or similar elements of the different embodiments are identified by identical reference symbols across all figures. DETAILED DESCRIPTION OF THE INVENTION Description of an example device

[0031] The following describes a device for creating a 50mm perforated concrete structure by flat casting, as illustrated in the figure 5 which is not part of the present invention. The figures 1 to 4 illustrate part of the device, namely a mold 1.

[0032] The illustrated mold 1 comprises a mold block 10, advantageously a single, rigid, machined block including a horizontal molding plate 10a. This is made of a polymer material whose properties meet the following requirements: millability, low adhesion to concrete, scratch-free surface finish during mold manufacturing, resistance to alkalis, ease of cleaning (low fouling), high number of uses (more than 1000 operations), resistance to high temperatures, and sufficient rigidity to allow demolding of the part.

[0033] The polymer material chosen may advantageously be a polyolefin material in the form of layers. These layers may be high-density polyethylene (HDPE) layers with a molecular weight between 250,000 and 1,200,000 g / mol, and more specifically 500,000 g / mol. When the molding plate 10a is formed of a plurality of such layers, these are advantageously fastened together by means of screws, the heads of which may, where appropriate, constitute the raised sections described below.

[0034] The molding plate 10a includes recesses 12 designed to define the desired openings 13 in the structure ( figure 5 ). The mold block being machined, the recesses are formed in one piece with the molding plate 10a.

[0035] In the illustrated embodiment, the molding plate 10a has recesses with multiple heights, in this case four heights (h1, h2, h3, h4) (visible on the figure 3 Given these different heights of the recesses, the resulting structure will have variations (four) in its thickness. This is, of course, just one example; the molding plate could have a different number of recess heights, including recesses of the same height. The resulting structure will be described as a single or multiple offset structure, with "single" offset meaning a structure without any variation in its thickness.

[0036] In this embodiment, the structure is demolded once the concrete has hardened by inverting the mold block 10. To facilitate demolding, the recesses 12 advantageously have draft angles. These will, however, be relatively small compared to those provided for in prior art devices, taking into account the modifications made. They are thus advantageously less than 5 degrees, and preferably around 3 degrees.

[0037] In the described embodiment, all or part of the recesses 12 have a raised surface 15. In the illustrated embodiment, this raised surface 15 is created by screw heads 15a 2 that fix the molding plate 10a to a support 20. This raised surface 15 on the surface 12a of the recesses 12 is between 3 and 7 millimeters, and is preferably around 5 millimeters. Generally, the raised surface will preferably be equal to the thickness of the structure to be produced.

[0038] According to an advantageous embodiment, the mold block 10 includes formwork sides 11. These sides can either be formed as a single unit with the mold block 10, or be removable. The advantage of the latter configuration is that it allows for the creation of a grid that can be embedded in the fixing base.

[0039] The format of the molding plate 10a is preferably between 2000 and 3000 mm for the length, 1000 to 1500 mm for the width, with a thickness of 20 to 80 mm.

[0040] In the illustrated embodiment, the molding plate 10a, which forms the mold block 10, is attached to a rigid support 20 consisting of two support plates 21 and 22. The outer support plate 22 (the plate furthest from the molding plate 10a) serves two purposes: firstly, to improve the rigidity of the mold block 10, and secondly, to allow the attachment of turning straps 3 to the support plate 21 for the safe turning of the mold block 10 for the purpose of demolding the concrete part. The support plates 21 and 22 may be made of plywood or of the same material as the mold block 10, namely polymer. In an advantageous embodiment, the inner plate 21 (the support plate in contact with the molding plate 10a) is made of plywood or polymer, while the outer plate 22 is made of plywood.Unlike a metal mold, this solution offers the advantage of being customizable to meet the end user's requirements, inexpensive, easily replaceable, and requiring minimal handling equipment. It is clear that the invention is not limited to this configuration, and that the support can be designed to consist of a single support plate or more than two. Similarly, the mold block 10 can be formed as a single unit with the support 20.

[0041] As previously stated, the mold block 10 is fixed to the support 20 by means of screws 2 whose screw heads 15a protrude from the upper surface of the recesses so as to create an extra thickness 15 of material relative to the upper surface of the recesses 12. The screws 2 are advantageously arranged around the periphery of the mold block 10 / support 20 assembly, other screws can also be provided on internal recesses 12.

[0042] To facilitate the filling of the mold plate 10a during concrete pouring and the demolding of the part once the concrete has hardened, as well as to improve the distribution of the concrete on the mold plate 10a, the device includes means for generating agitation within the mold block 10 (not shown). These means may generate vibrations, such as vibrators, impacts, such as hammers, or preferably horizontal agitation, such as rollers or balls. Mold making process

[0043] The mold block 10 is made from a drawing or model of the mesh to be made, specifying the maximum height of the stiffeners and the different thicknesses of the recesses, redrawn in 3D with the integration of all the technical specifications (fruits, fillets, etc.).

[0044] Preferably, the mold block 10 will be manufactured to produce structures with lengths between 2000 and 3000 mm, widths between 1000 and 1500 mm, and thicknesses between 20 and 80 mm. The mold block 10 is, of course, not limited to producing structures of these dimensions. It can also be used to create smaller structures, particularly those that are easy to handle, allowing for on-site assembly if necessary. This does not, of course, preclude the production of mold blocks 10 with dimensions larger than those mentioned above. Method for creating an openwork structure using the device described above

[0045] According to an unclaimed aspect, the openwork concrete structure 50 is made with the device just described as follows.

[0046] The mold plate 10a is filled as follows: fresh concrete is poured flat onto the horizontally positioned mold plate 10a, to a specific height within the recesses 12, according to the desired thickness of the structure to be obtained. The mold plate 10a is advantageously filled in at least two passes, potentially with the addition of energy to reduce the shear stress of the fresh material and facilitate its flow into the mold block 10. This energy can be applied using agitation methods as described previously.

[0047] After the concrete has hardened, the concrete structure is demolded (formwork removed). Demolding is done by inverting the mold (mold block 10 and support 20) onto a flat demolding support (preferably a plywood board).

[0048] Thanks to the clearance created between the mold block 10 and the demolding support by the screw heads 15a 2, as well as the draft angles and rigidity of the mold, the concrete part is demolded from the mold block 10 by sliding. To ensure the concrete structure slides smoothly and without damage, agitation can be applied to the outer surface of the mold support using the stirring means.

[0049] To facilitate the demolding of the concrete piece, it may also be planned to apply a demolding agent to the molding plate 10a prior to filling the latter.

[0050] In the described embodiment, the raised areas 15 on the upper surface of the molding plate 10a are formed by the screw heads. This is, of course, only one example of an embodiment; any other means or technique generating a raised area on the surface of the plate falls within the scope of the invention. For example, this could be a raised area of ​​material originating from the molding plate 10a.

[0051] In the embodiment just described, which is not part of the invention, the mold block 10 comprises a horizontal molding plate. The casting is carried out horizontally. According to the invention, the casting is carried out vertically. In this case, the mold block 10 comprises first and second molding plates arranged to define, when positioned in contact with each other along a vertical parting line, a closed lower end and an opening for pouring concrete between said molding plates. Preferably, the opening will be provided at the upper end when the two molding plates are positioned in contact with each other. It is understood that the opening can also be located at one of the lateral edges of the formed mold block 10.It may also be possible to design the mold block 10 to have several openings for pouring concrete in order to facilitate and optimize the pouring time between the two plates. It may also be possible to design the concrete pouring process to be carried out on an inclined plane, particularly during the pouring phase, in order to promote a preferential fiber orientation.

[0052] Advantageously, the two molding plates are equipped with pins or other fasteners that ensure perfect continuity of the faces at the junction of the two molds. The two molding plates are joined together by bolting, for example, using centering screws. This allows them to withstand the hydrostatic pressure applied to the walls of the molding plates during the concreting operation.

[0053] Once the concrete has hardened, the formwork is removed by laying the mold flat, preferably with the lower mold plate secured to a support. The bolts are then removed, and the upper mold plate is lifted out or extracted using screws. The piece (concrete + lower mold plate) is then rotated 180° and placed on a demolding support, following the same procedure as for flat casting.

[0054] It is also possible to remove the formwork from a vertical position. To do this, the mold must be turned over to position the structure so that it rests on a support, which is then secured, for example, with a pin. The bolts joining the two plates are then removed, and the two plates are then separated using extraction screws. Application of the resulting openwork structures

[0055] Among the applications envisaged, we can mention the use of the openwork structures obtained using the device described above in particular, but not exclusively, as facade cladding, wall cladding, railings, sunshades, pool surrounds, stairwells, sliding gates, fences, bus shelter surrounds, parking payment terminals, pool access stairs and indoor and outdoor furniture.

[0056] The structure's fastening system will potentially vary depending on its intended use and purpose. The fastening system is advantageously designed to withstand the environmental conditions of its surroundings and to contribute to the absorption and transmission of forces applied to the mesh. It may advantageously incorporate a viscoelastic material to absorb shocks perpendicular to the mesh. The fastening system may also be designed to be molded into the structure itself.

[0057] In the embodiments described above, the mold 1 is formed of separate elements: a molding plate and a support. According to one alternative embodiment, the mold may be a single-piece polyolefin mold. In this alternative embodiment, the fastening straps and stirring means would be directly integrated into the single-piece mold.

[0058] The invention is described above by way of example. It is understood that a person skilled in the art is able to carry out different embodiments of the invention without departing from the scope of the invention as defined by the claims.

Claims

1. Device for producing a perforated concrete structure having a multiple offset on the thickness (50), comprising a rigid mould block (10) which is made of machined polymer, comprising a first one-piece moulding plate (10a) and a second moulding plate, said first moulding plate (10a) comprising reservations (12) of multiple heights, having respectively a clearance of less than 10 degrees, and the first and second moulding plates being arranged to define, when they are positioned in contact with one another along a vertical joint line, a closed lower end and an opening for the pouring of concrete between said first and second moulding plates.

2. Device according to claim 1, characterised in that the clearances are lower than 5 degrees, and preferably are around 3 degrees.

3. Device according to claim 1 or claim 2, characterised in that the mould block comprises removable side-forms or formed of one single piece with the first moulding plate (10a).

4. Device according to any one of the preceding claims, characterised in that the first moulding plate (10a) is secured to a rigid support constituted of at least one veneered plate or of the same type as said moulding plate (10a).

5. Device according to claim 4, characterised in that it comprises means for returning the support.

6. Device according to any one of the preceding claims, characterised in that it comprises means for generating a stirring within the mould block (10).

7. Method for producing a perforated concrete structure (50) by means of a device according to any one of claims 1 to 6, comprising a vertical pouring operation, or operation in an inclined plane of a concrete in the fresh state into the mould block (10) formed of the first and second moulding plates, joined to one another through the opening provided at the moulding plates.

8. Method for producing a perforated concrete structure (50) according to claim 7, characterised in that the mould block (10) is subjected to actions generating a stirring within it, during the pouring operation and / or during the demoulding operation.

9. Method for producing a perforated concrete structure (50) according to claim 7 or claim 8, characterised in that the produced structure is a perforated structure with a multiple offset on the thickness.

10. Method for producing a perforated concrete structure (50) according to any one of claims 7 to 9, characterised in that the produced structure is a perforated concrete protection rail.

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