Shuttering element and method for constructing a concrete structure in a cavity

Abstract

The invention relates to a shuttering element and a method for constructing a concrete structure in a cavity. The shuttering element according to the invention is provided for constructing a vertical wall of a concrete structure intended to contain a liquid. The shuttering element (100) comprises a first shuttering panel (110) made from openwork sheet metal, a second shuttering panel (120) made from fibre-cement and a plurality of spacers (130). It is possible to use the shuttering element (100) reversibly in the construction method. The construction method allows the production of a shuttered structure from reinforced concrete, which structure is monobloc, non-deformable and not likely to crack. Furthermore, it is readily possible to widen the upper levelling of the walls in order to support the kerbstones without any risk of cracks and / or breakages. Furthermore, the structure is variable while being compatible with any finishing coating.

Description

Technical field

[0001] The invention relates to a formwork element and a method for constructing a concrete structure in a cavity. Prior art

[0002] A classic poured concrete structure intended to contain a liquid, and in particular a swimming pool, comprises a base (which forms the bottom of the structure) and generally vertical walls. Given its intended purpose, such a structure must be perfectly watertight.

[0003] Conventionally, such a structure can be waterproofed by applying a Polyvinyl Chloride (PVC) tarpaulin, known as a "liner." A liner completely covers the interior faces of the structure, which are oriented towards the inside of the structure, and is intended to be in contact with the liquid.

[0004] However, liners are known to have very low tear resistance, requiring complete replacement if damaged.

[0005] In view of this state of the art, the inventor determined that it could be advantageous to have a method of constructing a concrete structure which is waterproof ab initio and does not require the use of a liner to be waterproof. FR 2 897 378 A1 shows a formwork element according to the preamble of claim 1. Summary of the invention

[0006] The invention aims to overcome this drawback.

[0007] Thus, the invention relates to a formwork element according to claim 1.

[0008] The invention also relates to a method of constructing according to claim 8 a concrete structure in a cavity.

[0009] For this purpose, the invention provides a formwork element for the construction of a vertical wall of a concrete structure intended to contain a liquid.

[0010] The formwork element has internal faces and external faces which are respectively oriented towards the inside and the outside of the formwork element.

[0011] The formwork element includes: a first formwork panel made of perforated metal sheet, a second formwork panel made of fiber cement, and spacers fixed to the internal faces to keep the formwork panels parallel to each other and at a distance from each other.

[0012] Furthermore, the formwork element has at its lower end a lower opening made in one of the external faces, called the first external face, and through which the concrete can flow when the formwork element is installed in a vertical position.

[0013] In addition to the characteristics mentioned in the preceding paragraphs, the formwork element may have one or more additional characteristics among the following, considered individually or according to the possible technical combinations.

[0014] In a particular implementation, the lower opening extends across the entire width of the first outer face.

[0015] In another particular implementation, the spacers are articulated between a folded transport position in which the internal faces are pressed against each other and a deployed use position in which the internal faces are parallel to each other and at a distance from each other.

[0016] According to a particular embodiment, the internal faces each comprise a plurality of stiffeners, into which the plurality of spacers fit.

[0017] According to another particular embodiment, the formwork element further comprises a third panel made of openwork metal sheet, which is folded into at least two parts, called the first part and the second part, the first part and the second part each comprising an internal face and an external face.

[0018] Furthermore, the third panel is fixed on the second external face so that the external faces of the first part and the second part are oriented towards the outside of the formwork element and so as to: pressing the inner face of the first part, substantially below the upper opening, and arranging the second part, substantially at the level of the upper opening to form a predetermined acute angle between the inner face of the second part and a plane containing the upper opening.

[0019] Preferably, the upper opening extends over all or part of the width of the second external face.

[0020] According to one implementation, the formwork element further comprises a plurality of horizontal stiffeners fixed to the upper level of the second external face and to at least one side of the second part.

[0021] The invention also provides a method of constructing a concrete structure in a cavity, the structure being intended to contain a liquid.

[0022] The method according to the invention comprises the following steps: providing a plurality of formwork elements according to the above embodiments, vertically juxtaposing the plurality of formwork elements on a seating surface of the cavity, so as to orient the first openings towards the interior of the cavity, arranging first reinforcements inside the plurality of formwork elements, arranging second reinforcements on the seating surface of the cavity, so as to insert all or part of the ends of the second reinforcements into the lower openings, pouring fresh concrete, first, inside the plurality of formwork elements, in order to produce walls of the structure, and pouring fresh concrete, then, on the seating surface of the cavity, in order to produce the raft, while the concrete inside the plurality of formwork elements is still fresh.

[0023] In a particular implementation, the method further comprises the following step, when the first external faces of the plurality of formwork elements are made of fiber cement: applying a first layer of a first liquid waterproofing membrane to the outer faces of each of the plurality of formwork panels, such that the first liquid membrane forms a first waterproof shell upon drying.

[0024] In another particular implementation, the method further comprises the following step: applying a second layer of a second liquid waterproofing membrane to the first waterproof shell, so that the second liquid membrane forms a second waterproof shell upon drying.

[0025] According to a particular embodiment, the first liquid membrane and the second liquid membrane are applied in crossed layers.

[0026] According to another particular embodiment, the first liquid sealing membrane is different from the second liquid sealing membrane.

[0027] According to yet another particular embodiment, a finishing coating is applied to the first waterproof hull or to the second waterproof hull.

[0028] Other aims, characteristics and advantages of the invention will appear on reading the following description, which refers to the appended figures which represent preferred embodiments of the invention, which are given solely as non-limiting examples. Brief description of the drawings

[0029] [ Fig. 1 ] There figure 1 represents a formwork element according to the invention, in the installation position on a seating surface of a cavity. Fig. 2 ] There figure 2 represents the third formwork panel of the formwork element of the figure 1 . [ Fig. 3 ] There figure 3represents a profile view of the third formwork panel of the figure 2 . [ Fig. 4 ] There figure 4 represents the formwork panel of the figure 2 when installed on the formwork element of the figure 1 . [ Fig. 5 ] There Figure 5 represents the arrangement of the figure 4 with the fixing of stiffeners on the upper course of the formwork element. Fig. 6 ] There figure 6 represents the arrangement of the figure 4 with the fixing of stiffeners on the third formwork panel of the figure 2 . [ Fig. 7 ] There figure 7 represents a method of constructing a concrete structure in a cavity. Fig. 8 ] There figure 8 represents a classic arrangement of a coping stone on a wall of a liquid retention basin. Fig. 9 ] There figure 9 represents a conventional arrangement of a coping stone on a wall of a liquid retention basin obtained according to an implementation of the invention.

[0030] The figures do not necessarily respect the scales, particularly in thickness, and this is for illustration purposes. Description of the embodiments

[0031] The formwork element according to the invention is intended for the construction of a vertical wall of a concrete structure intended to contain a liquid.

[0032] In one example, the structure is a swimming pool and the liquid is water. However, the invention also covers any liquid retention basin and any liquid adapted to be contained in the liquid retention basin.

[0033] In the remainder of the description, the terms "upper", "lower", "top" and "bottom" refer to the arrangement of the formwork element in the figures, which generally corresponds to its installation arrangement on a seating surface of a cavity. The seating surface is understood to mean the bottom of the cavity, which is generally flat and horizontal.

[0034] Generally, the formwork element is intended to be installed in a vertical position. In addition, it has internal and external faces that are oriented towards the inside and outside of the formwork element, respectively. Furthermore, the formwork element is configured to allow concrete to be poured into its interior from its upper part.

[0035] In the figure 1 , the formwork element 100 comprises a first formwork panel 110, a second formwork panel 120 and a plurality of spacers 130.

[0036] In the example of the figure 1 , the first formwork panel 110 is made of openwork metal sheet.

[0037] In another example, the first formwork panel 110 is of the same type as those marketed under the brand name Métalévolué, namely, a sheet metal perforated by multiple incisions, in staggered rows, of a sheet of metal, then by extension in order to open these incisions.

[0038] In this example, the formwork panel 110 may have openings less than or equal to 16 mm by 7 mm for a thickness greater than or equal to 1 mm, or have openings less than or equal to 28 mm by 9 mm for a thickness greater than or equal to 1.5 mm. However, the invention also covers other dimensions without requiring modifications to the principles of the invention.

[0039] In a particular implementation, the first formwork panel 110 has an internal face and an external face which are respectively oriented towards the inside and the outside of the formwork element 100. Thus, the internal face and the external face of the first formwork panel 110 correspond respectively to one of the internal and external faces of the formwork element 100.

[0040] In another particular implementation, the first formwork panel 110 is made of galvanized steel to protect the steel against oxidation.

[0041] The first formwork panel 110 thus configured allows the concrete to spread and transpire slightly through the openings so as to limit the thrust forces experienced by the second formwork panel 120.

[0042] In the example of the figure 1 , the second formwork panel 120 is made of fiber cement, namely, a prefabricated material consisting of very fine fibers agglomerated by a cement binder.

[0043] This material is advantageous because it is water-resistant and unalterable by the humidity and laitance brought by the concrete poured during the construction of the structure, nor subsequently by the liquid contained in the structure. Furthermore, with the construction process that will be described below, it will be shown that this material does not need to be covered with a finishing coating, such as Polyvinyl Chloride (PVC) tarpaulins called "liners" in English, to make the structure waterproof.

[0044] In one example, the second formwork panel 120 is of the same type as those marketed under the Fibrociment brand and has a thickness of approximately 1 cm. However, the invention also covers other types of products and other dimensions without requiring modifications to the principles of the invention.

[0045] In a particular implementation, the second formwork panel 120 has an internal face and an external face which are respectively oriented towards the inside and the outside of the formwork element 100. Thus, the internal face and the external face of the second formwork panel 120 correspond respectively to one of the internal and external faces of the formwork element 100.

[0046] In practice, the external face of the second formwork panel 120 is solid, flat and smooth, which is not necessarily the case for the internal face of the second formwork panel 120.

[0047] In the example of the figure 1, spacers 130 are fixed to the internal faces of the formwork element 100 to keep the first formwork panel 110 and the second formwork panel 120 parallel to each other and at a distance from each other.

[0048] In one example, the spacers 130 have a thickness of at least 15 cm to ensure the structure is watertight. However, the invention also covers other dimensions without requiring modifications to the principles of the invention.

[0049] In a particular implementation, the spacers 130 are articulated between a folded transport position in which the internal faces of the formwork element 100 are pressed against each other and a deployed use position in which the internal faces of the formwork element 100 are parallel to each other and at a distance from each other.

[0050] In this implementation, a known type of articulation mechanism can be used.

[0051] In another particular implementation, the spacers 130 comprise anchor heads for fitting into stiffeners 103.

[0052] In this particular implementation, the internal faces of the formwork element 100 each comprise a plurality of stiffeners 103 into which the anchor heads of the plurality of spacers 130 fit.

[0053] In one example, the stiffeners 103 are formed from galvanized steel rails to have a U-shaped cross-section. The stiffeners 103 include a web, two flanges that extend along the side edges of the web, and two flange returns that extend the flanges such that the flange returns extend in a plane parallel to the plane of the web.

[0054] In this example, the stiffeners 103 are fixed to the internal faces of the formwork element 100 by screws and are arranged so as to extend vertically when the formwork element 100 is in the installation position.

[0055] The stiffeners 103 have a predetermined length such that they extend projecting from the bottom of the first formwork panel 110 or the second formwork panel 120 and delimit a lower opening 101 which allows the passage of concrete.

[0056] In other words, the formwork element 100 comprises at its lower end, the lower opening 101 which is made in one of its external faces, called the first external face, and through which the concrete can flow.

[0057] In one example, the lower opening 101 extends across the entire width of the first outer face.

[0058] This arrangement has the effect of making the formwork element 110 reversible, particularly in its use in the construction method described below. Thus, the formwork element can be oriented in any direction desired, as long as the lower opening 101 is left at the bottom of the formwork element 100.

[0059] Indeed, in a first example, the first external face corresponds to the external face of the first formwork panel 110. This configuration makes it possible to obtain a wall with good metallic adhesion which is suitable for certain types of coatings. These are, for example, coatings of the undercoat type (conventional mortar) or finishing coatings applied in thickness (for example, approximately 2.5 cm).

[0060] On the other hand, in a second example, the first external face corresponds to the external face of the second formwork panel 120. This configuration makes it possible to obtain a wall suitable for all types of finishing covering such as “liners”, tiles or paint.

[0061] In an optional implementation, given the example of the figure 1 , the formwork element 100 also comprises at its upper end, an upper opening 102 made in the other of the external faces of the formwork element 100, called the second external face.

[0062] Thus, due to the reversibility of the formwork element 100, if the lower opening 101 is made in the first formwork panel 110 then the upper opening 102 will be made in the second formwork panel 120. On the contrary, if the lower opening 101 is made in the second formwork panel 120 then the upper opening 102 will be made in the first formwork panel 110.

[0063] In one example, the upper opening 102 extends across all or part of the width of the second outer face. For example, in the figure 1 , the upper opening 102 corresponds to a cutout of the second formwork panel around the stiffeners 103.

[0064] In this optional implementation, the formwork element 100 also comprises a third formwork panel 140 made of perforated metal sheet of the same type as the first formwork panel 110. However, as illustrated in the figure 2, the third formwork panel 140 is significantly less wide than the first formwork panel 110.

[0065] In a particular implementation, the width of the third formwork panel 140 is less than about one-third of the width of the first formwork panel 110, preferably less than half the width of the first formwork panel 110.

[0066] Furthermore, as illustrated in the figure 3 , the third formwork panel 140 is folded into at least two parts, called first part 131 and second part 132. The first part 131 and the second part 132 each comprise an internal face and an external face.

[0067] In this optional implementation, as illustrated in the figure 4, the third panel 140 is fixed orthogonally on the second external face, so that the external faces of the first part 131 and of the second part 132 are oriented towards the outside of the formwork element 100, so as to press the internal face of the first part 131, substantially below the upper opening 102 and so as to arrange the second part 132, substantially at the level of the upper opening 102 to form a predetermined acute angle α between the internal face of the second part 132 and a plane which contains the upper opening 102.

[0068] In one example, the first part 131 is fixed to the second external face by screws on the stiffeners 103 mounted on the first formwork panel 110.

[0069] In another example, the acute angle α is between about 0° and about 90°, preferably between about 30° and about 50°.

[0070] This optional implementation has the effect of allowing the upper course of the concrete wall to be widened according to the desired dimension L so that it can support coping stones, often made of natural or reconstituted stone, without the risk of cracks and / or breakage. This wider upper course can be reinforced by arranging reinforcements in the space created.

[0071] Indeed, the perimeter of a liquid retention basin generally includes coping stones that separate the basin from a terrace formed around the pool. As illustrated in the figure 8, in the prior art, a coping stone 300 rests partly on the upper course of a wall 400 of the liquid retention basin and partly on the embankment 500 which is located on the side of the ground in place 600, because the width of the coping stone 300 is greater than that of the wall 400. Indeed, the width of a coping stone 300 is generally twenty-five to thirty-five centimeters, while the width of the wall 400 is of the order of 15 cm. However, over time, the embankment 500 sags and the coping stone 300 is then cantilevered with the risk of cracking and / or breaking. Thus, as illustrated in the figure 9 , the solution according to the invention makes it possible to better support the edges of the 300 edge type.

[0072] In an example of this optional implementation, as illustrated in the figures 5 And 6, the formwork element 100 further comprises a plurality of horizontal stiffeners 104 fixed to the upper level of the second external face and to at least one side of the second part 131.

[0073] In one example, the horizontal stiffeners 104 are fixed to the upper level of the second external face and to one of the sides of the second part 131 by screws. For example, one of the sides of the second part 131 may be the upper side and / or a lateral side.

[0074] The invention also covers a method of constructing 200 a concrete structure in a cavity.

[0075] In one example, the cavity is an excavation made in the ground.

[0076] In another example, the cavity is a reservoir of an existing retention basin. This arrangement has the effect of allowing the renovation of the damaged existing retention basin without requiring excavation or the removal or dismantling of the existing retention basin.

[0077] In step 210, called supply, a plurality of formwork elements 100 are supplied as described above.

[0078] In step 220, called juxtaposition, the plurality of formwork elements are juxtaposed vertically on a seating surface of the cavity, so as to orient the first openings 101 towards the interior of the cavity.

[0079] In step 230, called first arrangement, first reinforcements are arranged inside the plurality of formwork elements 100.

[0080] In step 240, called second arrangement, second reinforcements are arranged on the seating surface of the cavity, so as to insert all or part of the ends of the second reinforcements into the lower openings 101.

[0081] The arrangement of the first and second reinforcements is of the type known in the field of civil engineering. Moreover, both arrangements can be carried out at the same time.

[0082] In step 250, called first pouring, fresh concrete is poured, first, inside the plurality of formwork elements 100, in order to create walls of the structure.

[0083] Fresh concrete is the state of the concrete when it has not started its setting and hardening process.

[0084] The first pour causes the concrete to ooze out through the lower openings 101.

[0085] In step 260, called second pouring, fresh concrete is then poured onto the seating surface of the cavity, in order to create the foundation, while the concrete inside the plurality of formwork elements is still fresh.

[0086] The second pouring results in the concrete poured onto the seating surface mixing with the concrete which oozes from the openings 101, to form a single-piece, reinforced concrete structure which is non-deformable and does not risk cracking.

[0087] Traditionally, the concrete is pulled onto the upper face of the slab to obtain a flat, smooth surface.

[0088] In one example, the raft is made to have a thickness of at least 15 cm to ensure the structure is watertight. However, the invention also covers other dimensions without requiring modifications to the principles of the invention.

[0089] In a particular implementation, the method further comprises a step 270, called first application, in which, when the first external faces of the plurality of formwork elements 100 are made of fiber cement, a first layer of a first liquid waterproofing membrane is applied to the external faces of each of the plurality of formwork panels 100, so that the first liquid membrane forms a first waterproof shell when drying.

[0090] In this particular implementation, the method further comprises a step 280, called second application, in which a second layer of a second liquid sealing membrane is applied to the first waterproof shell, so that the second liquid membrane forms a second waterproof shell when drying.

[0091] In one example, the first liquid membrane and the second liquid membrane are applied in cross layers, namely, alternately in one direction, then in a perpendicular direction.

[0092] The application of a liquid membrane reinforces the waterproofing of the structure, because it adheres to the fiber-cement material by blocking all or part of the pores of the material.

[0093] The cross-layer application is suitable for allowing the longitudinal and transverse placement of the fibers of the second formwork panel 120.

[0094] In another example, the first liquid waterproofing membrane is different from the second liquid waterproofing membrane.

[0095] The structure thus obtained can be used as it is without the application of a liner, because it is waterproof. ab initio.

[0096] Indeed, the combination of a concrete shell, a fiber cement panel, and a liquid membrane prevents water migration from the exterior of the structure to its interior. This migration water is generally rainwater that migrates into the embankment surrounding the structure. This migration phenomenon accounts for more than 50% of water retention basin disasters. However, using a liner as a waterproofing system does not prevent this phenomenon. On the contrary, in this case, unsightly pockets of water tend to form.

[0097] Furthermore, with the structure according to the invention, the watering is immediate, unlike structures which require the use of a liner, for which the liner must first be manufactured in the factory according to the measurements of the structure.

[0098] In yet another example, a finishing coating is applied to the first waterproof shell or the second waterproof shell, such as liners, tiles, or paint. In this way, the structure according to the invention is scalable, as any finishing coating can be applied later. For example, years later after the application of the liquid membrane.

Claims

1. A shuttering element (100) for constructing a vertical wall of a concrete structure intended to contain a liquid, the shuttering element having inner faces and outer faces which are respectively oriented toward the interior and exterior of the shuttering element, the shuttering element comprising: - a first shuttering panel (110) made of perforated sheet metal, - a second shuttering panel (120) made of fiber cement, and - spacers (130) fixed to the inner faces to keep the shuttering panels parallel to each other and at a distance from each other, characterized in that the shuttering element comprises: - an opening, said lower opening (101), made in one of the outer faces, referred to as the first outer face, at a first end of the first outer face, - an opening, said upper opening (102), made in the other outer faces, said second outer face, at a second end opposed to the first end, in order to form a reversible shuttering element whose orientation depends on the finishing to be applied, and whose opening arranged at the lower end of the shuttering element, one the shuttering element arranged in the vertical position, allows the concrete to may flow.

2. The shuttering element according to claim 1, wherein the lower opening extends over the entire width of the first outer face.

3. The shuttering element according to any of claims 1 to 2, wherein the spacers are articulated between a folded transport position in which the inner faces are held against each other and a deployed position of use in which the inner faces are parallel to each other and at a distance from each other.

4. The shuttering element according to any of claims 1 to 3, wherein the inner faces each comprise a plurality of stiffeners (103) into which the plurality of spacers are fitted.

5. The shuttering element according to any of claims 1 to 4, further comprising: - a third panel (130) made of perforated sheet metal, which is folded at least in two parts, referred to as the first part and second part, the first part and the second part each comprising an inner face and an outer face, wherein the third panel is fixed on the second outer face so that the outer faces of the first part and of the second part are oriented toward the outside of the shuttering element and in such a way as to: - hold the inner face of the first part substantially below the upper opening, and - arrange the second part substantially at the level of the upper opening to form a predetermined acute angle between the inner face of the second part and a plane containing the upper opening.

6. The shuttering element according to claim 5, wherein the upper opening extends over all or part of the width of the second outer face.

7. The shuttering element according to any of claims 5 or 6, further comprising a plurality of horizontal stiffeners (104) fixed on the upper leveling of the second outer face and on at least one side of the second part.

8. A method (200) for constructing a concrete structure in a cavity, the structure being intended to contain a liquid, the method comprising the following steps: - providing (210) a plurality of shuttering elements according to any of claims 1 to 6, - vertically juxtaposing (220) the plurality of shuttering elements on a bottom surface of the cavity, so as to orient the first openings toward the interior of the cavity, - arranging (230) first reinforcements inside the plurality of shuttering elements, - arranging (240) second reinforcements on the bottom surface of the cavity, so as to insert all or part of the ends of the second reinforcements in the lower openings, - first pouring (250) fresh concrete inside the plurality of shuttering elements in order to form the walls of the structure, and - then pouring (260) fresh concrete on the bottom surface of the cavity in order to form the concrete slab while the concrete inside the plurality of shuttering elements is still fresh.

9. The method according to claim 8, further comprising the following step, when the first outer faces of the plurality of shuttering elements are made of fiber cement: - applying (270) a first layer of a first watertight liquid membrane on the outer faces of each of the plurality of shuttering panels, so that the first liquid membrane forms a first watertight shell upon drying.

10. The method according to claim 8 further comprising the following step: - applying (280) a second layer of a second watertight liquid membrane on the first watertight shell, so that the second liquid membrane forms a second watertight shell upon drying.

11. The method according to claim 10, wherein the first liquid membrane and the second liquid membrane are applied in crossed layers.

12. The method according to any of claims 10 or 11, wherein the first watertight liquid membrane is different from the second watertight liquid membrane.

13. The method according to any of claims 10 to 12, wherein a finishing covering is applied to the first watertight shell or to the second watertight shell.

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