A prefabricated reinforced concrete wall for use in formwork for the construction of a concrete wall

Abstract

A prefabricated reinforced concrete wall, called a "uniwall," configured for use in formwork to construct a concrete wall against an existing wall, where the existing wall forms part of the formwork and the prefabricated concrete wall forms part of the concrete wall, and the uniwall comprises a single concrete slab. Figure to be published for the abstract: Fig. 5

Description

Title of the invention: A PREFABRICATED REINFORCED CONCRETE WALL FOR USE IN FORMWORK FOR THE CONSTRUCTION OF A CONCRETE WALL Technical field

[0001] The present invention relates to precast reinforced concrete elements configured for use in a formwork for constructing a concrete wall adjacent to an existing wall and wherein the precast reinforced concrete element forms part of the final concrete wall. The invention also relates to a formwork which comprises the precast reinforced concrete elements, as well as to a method of constructing said formwork and a method of constructing the concrete wall. State of the art

[0002] Prefabricated reinforced concrete elements as described above are known. The company Ploegsteert, for example, produces prefabricated "double walls" intended to be used in formwork for constructing a concrete wall adjacent to an existing wall and in which the prefabricated "double wall" is part of the concrete wall. Such a "double wall" is shown in [Fig. 1]. These "double walls" comprise two concrete slabs 1, 2 extending over a given "slab height" in a first direction indicated by the arrow "x", in use substantially parallel to the gravitational direction, from a lower portion 3 to an upper portion 4. The two concrete slabs of the "double wall" are parallel to each other and form an empty space 5 between them.The "double wall" further comprises one or more reinforcing members, wherein each reinforcing member comprises a lower elongated metal bar 6, an upper elongated metal bar 7 substantially parallel to the lower elongated metal bar and a metal mesh 8 connecting the lower elongated metal bar 6 to the upper elongated metal bar 7. The lower elongated metal bar 6 of the reinforcing member is located inside a first concrete slab 1 (of the two concrete slabs in the "double wall") while the upper elongated metal bar 7 is located inside the second concrete slab 2. In other words, the reinforcing member connects the first and second concrete slabs 1 and 2 of the "double wall" together. In use, the prefabricated "double wall" is transported from the production site, for example Ploegsteert, to the construction site.At the construction site, the prefabricated “double wall” is placed on a previously constructed concrete floor slab 9, parallel and adjacent to an existing wall 10 which constitutes the foundation or basement of the construction to be built. The existing wall 10 . is in particular an existing concrete-based wall formed as an earth retaining wall. Different methods are used to construct these earth retaining walls, such as cutter soil mix walls, "Berlin" type walls or "pile" type walls. The company "Franki Foundations" is renowned for the construction of these earth retaining walls. In order to form the concrete wall, the empty space 5 between the two concrete slabs 1, 2 is filled with concrete 11. The reinforcing members that connect the two concrete slabs 1, 2 ensure that the two concrete slabs do not separate from each other due to the horizontal concrete pressure applied by the liquid concrete on the concrete slabs. After the concrete 11 has hardened, the final concrete wall is obtained. The concrete slab 1 that is not facing the existing wall now serves as the interior wall of the building.

[0003] It is further known in the prior art to use reusable formwork elements to construct the final concrete wall. Such a reusable formwork element is for example known from the company "Doka", and is shown in [Fig. 2]. These reusable formwork elements are relatively light metal structures comprising a floor portion 13 and a wall portion 14 connected to the floor portion 13 by means of a stud 12, and in which the wall portion comprises a molding plate 15. The reusable formwork element is placed on the previously constructed concrete floor slab 9, so that the molding plate 15 faces the existing wall 10 and is parallel to it. These reusable formwork elements, however, have several disadvantages. The construction and deconstruction of such reusable formwork is very time-consuming.Furthermore, when using such lightweight reusable formwork elements, the lack of weight must be compensated for by providing a high-strength floor anchor 16 in the concrete floor slab 9. This high-strength floor anchor 16 requires the embedding of metal rods in the floor slab when pouring the concrete floor slab. Not only does this slow down the construction of the floor slab, but it also results in additional post-processing steps. Indeed, when deconstructing the reusable formwork elements, the high-strength floor anchor rods 16 must be partially removed, and the damage to the floor slab 9 after said removal must be repaired. Furthermore, due to the high manufacturing costs of such a reusable formwork element, a limited quantity of elements is purchased.Therefore, there are often not enough reusable formwork elements available on the construction site to create all the concrete walls at once, requiring the staged creation of concrete wall segments. Detailed description

[0004] The present inventors have discovered that "double walls" are complex to transport due to their high weight and bulky construction. There is therefore a need to provide precast reinforced concrete elements configured for use in formwork for constructing a concrete wall adjacent to an existing wall and in which the precast concrete element is part of the concrete wall, the problem of the prior art being solved.

[0005] To this end, the present invention provides a prefabricated reinforced concrete wall, called a "uniwall", configured to be used in a formwork for constructing a concrete wall against an existing wall, wherein the existing wall is part of the formwork and wherein the prefabricated concrete wall is part of the concrete wall, i.e., it is part of the final concrete wall, i.e., it is not removed after forming the concrete wall. The uniwall comprises a concrete slab extending over a given "slab height" in a first direction, in use substantially parallel to the gravitational direction, from a lower portion, in particular from a lower edge, to an upper portion, in particular to an upper edge. In particular, the uniwall comprises a single concrete slab as opposed to the two concrete slabs that are provided in the previously mentioned "double wall" of the prior art.The slabs are preferably flat slabs. The dimensions of the slab are, for example, between 3 and 5 meters in the first direction, and between 5 and 15 meters in a second direction perpendicular to the first. The uniwall further comprises at least one lattice beam. Preferably, the uniwall comprises more than one lattice beam, i.e., at least two lattice beams. The lattice beam comprises a lower elongated metal bar, an upper elongated metal bar substantially parallel to the lower elongated metal bar, and a metal lattice, for example, a continuous metal bar, connecting the lower elongated metal bar to the upper elongated metal bar. The lattice has, for example, a substantially sinusoidal shape in which the peaks are connected to the upper bar and in which the troughs are connected to the lower bar.Preferably, the lattice beam comprises a second additional lower bar substantially parallel to the first lower bar, wherein the additional lower bar is also connected to the upper bar by means of an additional lattice, or is connected to an additional upper bar by means of an additional lattice. Other types of reinforcing members may of course be used. Preferably, at least one lattice beam is a vertical lattice beam extending substantially in the first direction. Preferably, at least one lattice beam is a horizontal lattice beam extending in a second direction substantially perpendicular to the first direction. Preferably, the uniwall comprises one or more beams. vertical lattice beams and / or one or more horizontal lattice beams. The lower elongated metal bar (or bars, if any) is located inside the concrete slab while the upper elongated metal bar (or bars, if any) is located outside the concrete slab. This makes the upper elongated metal bar accessible by a user from a first side of the concrete slab, said side being called the inner side as opposed to the opposite side of the concrete slab which is called the outer side. Preferably, the concrete slab comprises two opposing major surfaces, the inner surface exposed to the inner side of the concrete slab, and the outer surface exposed to the outer side of the concrete slab.For clarity, the upper elongated metal bar is accessible by a user from the interior side of the concrete slab by allowing the mesh to penetrate the interior surface of the concrete slab. Further, the upper elongated metal bar is freely accessible by a user from the first side of the concrete slab. This upper bar is freely accessible because it is not embedded within a second concrete slab, as is the case in the prior art "double wall" mentioned previously.

[0006] The present inventors have discovered that by using the uniwall, a formwork can be created in which the existing wall is part of the formwork. This avoids the need to incorporate a second concrete slab into the precast element, as is the case in the previously mentioned prior art "double walls". The uniwall therefore has a lower weight and is less bulky than the prior art "double wall". It is therefore less complex to transport the uniwall than to transport the prior art "double wall". Furthermore, none of the disadvantages of the previously mentioned reusable formwork are present when using the uniwall.

[0007] According to one embodiment of the present invention, a first row of stud connectors is provided within the concrete slab. The first row of stud connectors is provided such that the stud connectors are accessible for removably connecting the studs to the concrete slab from the exterior side of the concrete slab. The stud connectors are accessible from the exterior side of the concrete slab because the stud connectors open into the exterior surface of the concrete slab. Preferably, the stud connectors do not open into the interior surface of the concrete slab. Preferably, the stud connectors are threaded sockets. The studs preferably include a threaded portion that can be removably screwed into the threaded socket.The studs, when connected to the stud connectors, connect the uniwall with the floor slab and support the uniwall while the formwork is filled with concrete. This is because the liquid concrete exerts pressure. on the uniwall. In the absence of the second concrete, as is the case in the “double walls” of the prior art, it is the dowels that counter the pressure of the liquid concrete. The dowels are preferably adjustable dowels that can be placed in compression or tension between the floor slab and the uniwall. Indeed, when the dowels are connected to dowel connectors in the lower portion of the concrete slab, the dowels are preferably placed in compression, whereas when the dowels are connected to dowel connectors in the upper portion of the concrete slab, the dowels are preferably placed in tension. According to one embodiment of the present invention, the first row of dowel connectors extends substantially in a second direction substantially perpendicular to the first direction, i.e. along the width of the concrete slab.The number of dowel connectors per meter is preferably between 0.5 and 3, preferably between 1 and 2. According to one embodiment of the present invention, the first row of dowel connectors is positioned in the lower portion of the concrete slab, preferably below 50% of the height of the concrete slab, preferably below 40% of the height of the concrete slab, and preferably above 10% of the height of the concrete slab, preferably above 20% of the height of the concrete slab, preferably approximately 30% of the height of the concrete slab. As previously indicated, the dowels connected to these dowel connectors are preferably placed in compression.According to an alternative embodiment of the present invention, the first row of dowel connectors is positioned in the upper portion of the concrete slab, preferably above 50% of the height of the concrete slab, preferably above 60% of the height of the concrete slab, and preferably below 90% of the height of the concrete slab, preferably below 80% of the height of the concrete slab, preferably approximately 70% of the height of the concrete slab. As previously indicated, the dowels connected to these dowel connectors are preferably placed under tension. According to an embodiment of the present invention, a second row of dowel connectors is provided within the concrete slab.Like the first row of stud connectors, the second row of stud connectors is provided such that the stud connectors are accessible for releasably connecting the studs to the concrete slab from the exterior side of the concrete slab. The stud connectors are accessible from the exterior side of the concrete slab because the stud connectors open into the exterior surface of the concrete slab. Preferably, the stud connectors do not open into the interior surface of the concrete slab. Preferably, the stud connectors are threaded sockets. According to one embodiment of the present invention, the second row of stud connectors . extends substantially in the second direction. The number of dowel connectors per meter is preferably between 0.5 and 3, preferably between 1 and 2. According to one embodiment of the present invention, the first row of dowel connectors is positioned in the lower portion of the concrete slab (preferably at the heights described above) and the second row of dowel connectors is positioned in the upper portion of the concrete slab, preferably above 50% of the height of the concrete slab, preferably above 60% of the height of the concrete slab, and preferably below 90% of the height of the concrete slab, preferably below 80% of the height of the concrete slab, preferably approximately at 70% of the height of the concrete slab.

[0008] According to an embodiment of the present invention, at least one, preferably at least two, for example two, L-shaped profile connectors, preferably implemented as threaded sockets, are provided in the lower portion of the concrete slab adjacent to a lower edge of the concrete slab. The L-shaped profile connectors are positioned closer to the lower edge of the concrete slab than the dowel connectors provided in the lower portion of the concrete slab. The L-shaped profile connectors are positioned so as to be accessible from the outer side of the concrete slab, i.e., they open at the outer surface of the concrete slab. The L-shaped profile connectors are configured to releasably connect to an L-shaped profile.The L-shaped profile is arranged to connect the concrete slab with the ground so as to prevent translation of the concrete slab during filling of the formwork with concrete. Multiple L-shaped profiles are preferably provided so that the L-shaped profiles can also exert a counter-moment along an axis perpendicular to the surface of the concrete slab. Such a counter-moment may be necessary to counter the moment applied to the concrete slab when the latter is provided with a concrete flow interruption device such as a "Stremaform ®" on one side (as will be described below).

[0009] According to one embodiment, at least two lifting anchors are provided within the upper portion of the concrete slab. The lifting anchors are provided so as to be accessible from the interior side of the concrete slab, i.e., the lifting anchors penetrate the interior surface of the concrete slab. The lifting anchor preferably comprises a loop, preferably a metal loop, which extends out of the interior surface of the concrete slab. The lifting anchors are configured to releasably connect to a crane hook so that the crane hook can lift the concrete slab. According to one embodiment of the present invention, a lifting anchor arm connector, preferably implemented as a threaded socket, is provided within the upper portion of the concrete slab and so as to be accessible from the exterior side of the concrete slab, i.e., the lifting anchor arm connector opens at the exterior surface of the concrete slab. The lifting anchor arm connector is configured to releasably connect to a lifting anchor arm comprising an additional lifting anchor. The provision of lifting anchors on both sides of the concrete slab allows the concrete slab to be supported in an upright position. The lifting anchor arm is not directly provided within the concrete slab, as are the lifting anchors previously described, because the exterior surface of the concrete slab is preferably minimally disturbed by permanent features, so as to improve the aesthetics of the exterior surface of the concrete slab.Preferably, one of the stud connectors, particularly one of the stud connectors provided in the upper portion of the concrete slab, is simultaneously the lifting anchor arm connector. After lifting the concrete slab into position adjacent to the existing wall, the lifting anchor arm can be disengaged from the lifting anchor arm connector, thereby releasing the lifting anchor arm connector for connection to a stud.

[0010] According to an embodiment of the present invention, the uniwall further comprises a concrete flow interruption grid such as a “Stremaform ®” type grid. The concrete flow interruption grid is connected to the concrete slab for example by means of connector arms embedded in the concrete slab. The grid is positioned on the inner side of the concrete slab. The connector arms penetrate for example the inner surface of the concrete slab. The grid allows the adjacent parts of the formwork to be filled in stages.

[0011] According to one embodiment of the present invention, a punching reinforcement is provided within the concrete slab at the positions of the dowel connectors. The punching reinforcement is preferably a set of metal rods preferably extending substantially in the second direction. The punching reinforcement is provided substantially only at the positions of the dowel connectors. For example, the set of metal rods extending substantially in the second direction is not provided with a continuous spacing in the first direction, rather the spacing is smaller around the position in the first direction where the dowel connectors are provided. Preferably, additional reinforcements are provided within the concrete slab, i.e., additional reinforcements other than the punching reinforcements.The additional reinforcements preferably comprise a first set of metal rods extending substantially in the first direction, a second set of metal rods extending substantially in the second direction, a third set of metal rods extending substantially in the first direction, wherein . the first, second and third sets are in different planes. These additional reinforcements are preferably provided along the entire first and second direction of the concrete slab, i.e., they are not concentrated around the dowel connectors. These additional reinforcements preferably have a substantially constant spacing between the metal rods of each set.

[0012] Another object of the present invention is to provide a formwork for constructing a concrete wall against an existing wall, the formwork comprising the uniwall as described above. The properties / embodiments described above relating to the uniwall apply mutatis mutandis to the uniwall incorporated in the formwork.

[0013] According to one embodiment of the present invention, the formwork further comprises the existing wall. At the construction site, the prefabricated uniwall is preferably placed on a previously constructed concrete floor slab parallel and adjacent to the existing wall. Preferably, the existing wall forms the foundation or basement of the construction to be constructed. Preferably, the existing wall is an existing concrete-based wall, for example formed as an earth retaining wall. Different methods can be employed to construct such earth retaining walls, such as cutter soil mix walls, "Berlin" type walls or "pile" type walls. The company "Franki Foundations" is renowned for the construction of such earth retaining walls. In use, after constructing the formwork, the space between the uniwall and the existing wall is filled with fresh liquid concrete and allowed to harden.This fresh liquid concrete coats the upper elongated metal bars of the lattice beam, so that these bars are no longer “freely accessible”.

[0014] According to one embodiment of the present invention, particularly when the existing wall is a "Berlin" type concrete retaining wall, a vibration damping layer is attached to the existing wall in the space between the uniwall and the existing wall. The vibration damping layer is preferably a double-walled sheet such as a "Biplex ®" sheet. The layer is preferably a plastic layer such as a polypropylene layer or a polycarbonate layer. This vibration damping layer makes it possible to destroy the existing wall after the construction of the final concrete wall, by vibrating the existing wall, without simultaneously destroying the uniwall and the concrete wall.

[0015] According to one embodiment of the present invention, the formwork further comprises a lifting anchor arm removably connected to the aforementioned lifting anchor arm connector. As previously described, in constructing the formwork, preferably the uniwall is positioned in place on the floor slab by providing the lifting anchor arm to the lifting anchor arm connector. After positioning the uniwall on the floor slab, the lifting anchor arm The lifting arm can be removed from the anchor arm connector and acts as a stud connector. This is because, after positioning the Uniwall on the floor slab, the studs are then connected to the stud connectors, which must therefore be freely accessible. This action is necessary when the lifting anchor arm connector is also accessible.

[0016] According to one embodiment of the present invention, the formwork further comprises dowels removably connected to the dowel connectors. The dowels connect the concrete slab to the floor slab.

[0017] According to one embodiment of the present invention, the formwork further comprises one or more L-shaped profiles, each being removably connected to one of the L-shaped profile connectors.

[0018] Another object of the present invention is to provide a method of constructing a formwork. The method comprises the steps of: • provide the uniwall as described above, and • create the formwork as described previously by placing the uniwall of adjacent to, and preferably substantially parallel to, an existing wall, such that the existing wall is on the interior side of the concrete slab. In this configuration, the truss, particularly its upper elongated metal bar, is placed in the space between the uniwall and the existing wall. Preferably, the truss bridges substantially the entire gap between the uniwall and the existing wall.

[0019] Another object of the present invention is to provide a method of constructing a concrete wall against an existing wall, the method comprising the steps of: • provide the formwork by carrying out the formwork construction process as described above, and • Fill the space between the uniwall and the existing wall with concrete. Concrete is a liquid concrete that will harden in the space between the uniwall and the existing wall.

[0020] According to one embodiment of the present invention, the step of filling the space between the uniwall and the existing wall with concrete comprises filling the space in stages. Preferably, each stage comprises filling the space to a predetermined height and waiting for a predetermined time to allow the concrete poured at said stage to harden. This preferred embodiment decreases the horizontal pressure exerted by the concrete on the uniwall. Preferably, the predetermined height and time are such that the maximum horizontal pressure exerted by the concrete on the uniwall during each stage is less than 50 kN / m2, preferably less than 30 kN / m2. Preferably, the predetermined height is less than 1.5 m, preferably less than 1 m, for example about 0.8 m for a predetermined duration of one hour.

[0021] According to one embodiment of the present invention, the concrete is a CEM I type concrete when the outside temperature at the installation site is below 15°C, while the concrete is a CEM III type concrete when the outside temperature at the installation site is above 15°C. Figures

[0022] [Fig.l] shows a sectional side view of a "double wall" known in the prior art.

[0023] [Fig.2] shows a sectional side view of a "reusable formwork element" known in the prior art.

[0024] [Fig.3a] shows a sectional side view of a uniwall-based formwork according to an embodiment of the present invention.

[0025] [Fig.3b] shows a lattice beam used in the uniwall of [Fig.3a].

[0026] [Fig.4a] shows a sectional side view of the uniwall of Figures 3 along a plane perpendicular to the second direction, in which additional elements were added to the uniwall.

[0027] [Fig.4b] shows four sectional views I, II, III and IV of the uniwall of [Fig.4a] along a plane including the first and second directions, in which views I, II, III, IV are sections along the arrows indicated in [Fig.4a].

[0028] [Fig.4c] shows a top view of the lattice girders and lifting anchors as shown in section V of the uniwall of [Fig.4a], in which the top view is taken in a plane including the first and second directions.

[0029] [Fig.5] shows a sectional side view of the uniwall-based formwork of Figures 3, in which additional elements have been added to the uniwall and in which the concrete pouring has been carried out in three phases.

[0030] [Fig.6], [Fig.7] and [Fig.8] show the steps of a process for creating the formwork of Figures 3 or 5.

[0031] [Fig.9] shows a perspective view of the uniwall of Figures 3 showing its interior surface, in which additional elements have been added to the uniwall.

[0032] [Fig. 10] shows a perspective view of the uniwall of Figures 3 showing its outer surface, in which additional elements have been added to the uniwall. Description of figures

[0033] The figures are described below. The same reference numbers designate the same technical features.

[0034] The present invention provides a prefabricated reinforced concrete wall, called a "uniwall", configured to be used in a formwork for constructing a concrete wall against an existing wall 10, in which the existing wall is part of the formwork and in which the prefabricated concrete wall is part of the concrete wall, i.e. it is part of the final concrete wall, i.e. it is not removed after forming the concrete wall.

[0035] As shown in [Fig.3a], the uniwall comprises a single flat concrete slab 18 extending over a given “slab height” in a first direction indicated by the arrow “x”, in use substantially parallel to the gravitational direction, from a lower portion 19, in particular from a lower edge 20, to an upper portion 21, in particular to an upper edge 22. The slab has a thickness extending between an inner main surface 43 and an outer main surface 44. The slab 18 is located adjacent and substantially parallel to the existing wall 10.The uniwall further comprises multiple lattice beams 23 comprising a lower elongated metal bar 24, an upper elongated metal bar 25 substantially parallel to the lower elongated metal bar and a metal lattice 26, formed as a continuous metal bar, connecting the lower elongated metal bar 24 to the upper elongated metal bar 25. The metal lattice 26 has a substantially sinusoidal shape in which the peaks are connected to the upper elongated metal bar 25 and in which the valleys are connected to the lower elongated metal bar 24. As shown in [Fig. 3b], the lattice beam 23 of [Fig. 3a] comprises an additional second lower bar 24 substantially parallel to the first lower bar 24, in which the additional lower bar is also connected to the upper bar 25 by means of an additional lattice 26.In Figures 3 as well as in the embodiment shown in [Fig. 5], only one vertical lattice beam 23, i.e., a lattice beam extending substantially in the first direction, is shown. However, the uniwall preferably comprises several vertical lattice beams, as shown for example in the other embodiments of the uniwall shown in Figures 4 and 9. In particular, in the embodiment of Figures 4, five vertical lattice beams 23 are shown. In Figures 3 as well as in the embodiment shown in [Fig. 5], no horizontal lattice beam 27, i.e., a lattice beam extending substantially in a second direction substantially perpendicular to the first direction, is shown.However, the uniwall preferably comprises one or more horizontal lattice beams 27, as shown for example in the other embodiments of the uniwall shown in Figures 4 and 9. In particular, in the embodiment of Figures 4 and 9, four horizontal lattice beams 27 are shown. In all cases, the metal bars . lower elongated bars 24 are located inside the concrete slab 18 while the upper elongated metal bar 25 is located outside the concrete slab 18. This makes the upper elongated metal bar 25 accessible by a user, before pouring the concrete 11 into the space 5 between the uniwall and the existing wall, from a first side of the concrete slab 18, said side being called the interior side as opposed to the opposite side of the concrete slab which is called the exterior side.

[0036] In order to form the concrete wall, the empty space 5 between the concrete slab 18 of the uniwall and the existing wall 10 is filled with concrete 11. After the concrete 11 has hardened, the final concrete wall is obtained. The outer surface 44 of the concrete slab 18 now acts as the interior wall of the building.

[0037] As clearly shown in Figures 4 and 6, a first row of stud connectors 31 and a second row of stud connectors 28, all implemented as threaded sockets, are provided inside the concrete slab 18. The first row of stud connectors 31 and the second row of stud connectors 28 are provided such that the stud connectors are accessible for releasably connecting studs 32 and studs 29 respectively to the concrete slab 18 from the outer side of the concrete slab 18. The studs comprise a threaded portion which can be releasably screwed into the threaded sockets of the stud connectors. The studs 29, 32, when connected to the stud connectors, connect the uniwall to the floor slab 9 and support the uniwall during filling of the formwork with concrete 11.The studs 29, 32 are adjustable studs which can be put more or less in tension between the floor slab 9 and the uniwall by means of a handle 30, 33. Indeed, since the studs 29 are connected to the stud connectors 28 in the upper portion 21 of the concrete slab 18, the studs 29 are preferably put in tension, while, since the studs 32 are connected to the stud connectors 31 in the lower portion 19 of the concrete slab 18, the studs 32 are preferably put in compression. The two rows of stud connectors 28, 31 extend substantially in a second direction substantially perpendicular to the first direction, that is to say along the width of the concrete slab. The second row of dowel connectors 28 is positioned in the upper portion 21 of the concrete slab at approximately 70% of the height H of the concrete slab 18.The height H is the distance between the lower edge 20 and the upper edge 22 of the concrete slab 18 along the first direction X. The first row of dowel connectors 31 is positioned in the lower portion 19 of the concrete slab approximately at 30% of the height H of the concrete slab 18. Figures 3, 5 and 8 show in detail the dowels connected to the dowel connectors.

[0038] As clearly shown in Figures 4 and 6, three L-shaped profile connectors 34, implemented in the form of threaded sockets, are provided in the lower portion 19 of the concrete slab 18, adjacent to a lower edge 20 of the concrete slab. The L-shaped channel connectors 34 are positioned closer to the lower edge 20 of the concrete slab 18 than the stud connectors 31 provided in the lower portion 19 of the concrete slab 18. The L-shaped channel connectors 34 are positioned so as to be accessible from the exterior side of the concrete slab 18. The L-shaped channel connectors 34 are configured to releasably connect to an L-shaped channel 35 by means of a bolt 38. This is clearly shown in Figures 7 and 8. The L-shaped channel 35 is arranged to connect the concrete slab 18 with the ground 9 so as to prevent translation of the concrete slab 18 when filling the formwork with concrete 11.When creating the formwork, the concrete slab 18 is positioned by means of a crane and lifting anchors connected to the concrete slab (as seen in [Fig. 6] and as will be described hereinafter), in close proximity to the floor slab 9 as shown in [Fig. 7]. A gap is typically left between the lower edge 20 of the concrete slab 18 and the floor slab 9 due to the unevenness of the floor slab 9. In order to prevent liquid concrete 11 from escaping from this gap, the gap is sealed by means of wooden barriers 36 and insulation foam 37. The wooden barriers 36 are bolted into the floor slab 9. After forming the final concrete wall, the L-profiles 35 can be removed from the L-profile connectors 24 so as to minimally disturb the aesthetics of the exterior surface of the uniwall.

[0039] As shown in Figures 4 and 9, lifting anchors 41 are provided within the upper portion 21 of the concrete slab 18. The lifting anchors 41 are provided so as to be accessible from the inner side of the concrete slab 18 when the space between the uniwall and the existing wall has not yet been filled with concrete 11. The lifting anchor comprises a metal loop, extending out of the inner surface of the concrete slab 18. The lifting anchors 41 are configured to releasably connect to a crane hook 40 so that the crane hook can lift the concrete slab and place it on the floor slab 9, as shown in [Fig. 6], where then, as shown in Figures 7 and 8, the concrete slab 18 is fixed to the floor slab 9 by means of the studs 29, 32 and the L-shaped profiles 35.Prior to the attachment of the studs 29, 32 to the stud connectors 28, 31, the stud connectors are therefore free to be used for other applications. One such application is the use of a stud connector 28 of the second row of stud connectors as a lifting anchor arm connector implemented as a threaded socket. The lifting anchor arm connector is configured to releasably connect to a lifting anchor arm 42. extending from a proximal side connected to the concrete slab 18 to a distal side further from the concrete slab 18. The distal side of the lifting anchor arm 42 includes an additional lifting anchor. The provision of lifting anchors on both sides of the concrete slab 18 allows the concrete slab to be supported in an upright position. The additional lifting anchor is spaced from the concrete slab 18 by a distance of at least 5 cm, so as to create a greater bending moment to maintain the concrete slab 18 in an upright position. The lifting anchor arm 42 is not directly, i.e., permanently, provided within the concrete slab, as are the lifting anchors 41 described above, because the outer surface of the concrete slab 18 is preferably minimally disturbed by permanent elements so as to improve the aesthetics of the outer surface of the concrete slab.

[0040] [Fig. 9] shows the uniwall of Figures 3 further comprising a concrete flow interruption grid 45 such as a “Stremaform ®” type grid. The concrete flow interruption grid 45 is connected to the concrete slab 18 for example by means of connector arms 46 embedded in the concrete slab 18. The grid 45 is positioned on the inner side of the concrete slab. The connector arms 46 penetrate in particular the inner surface of the concrete slab. The grid 45 allows the adjacent parts of the formwork to be filled in stages. Furthermore, a water stop 47 is connected to the flow interruption grid 45.

[0041] [Fig. 10] shows the uniwall of Figures 3 in which openings 48 are preformed, for example during the formation of the uniwall at the production site before transporting the uniwall to the construction site.

[0042] As clearly shown in Figures 4 and 5, a punching reinforcement 49 is provided inside the concrete slab 18 at the positions of the stud connectors 28, 31. The punching reinforcement 49 is a set of metal rods extending substantially in the second direction. The punching reinforcements 49 are provided substantially only at the positions of the stud connectors, i.e., they are concentrated around the stud connectors 28, 31.

[0043] As clearly shown in Figures 4, additional reinforcements are provided inside the concrete slab, i.e. additional reinforcements other than the punching reinforcements 49. The additional reinforcements comprise a first set of metal rods 50 extending substantially in the first direction, a second set of metal rods 51 extending substantially in the second direction, and a third set of metal rods 52 extending substantially in the first direction, the first, second and third sets being in different planes. These additional reinforcements are provided over the entire first and second direction of the concrete slab 18, i.e. that they are not concentrated around the stud connectors 28, 31. These additional reinforcements each have a substantially constant spacing between the metal rods of each set.

[0044] As clearly shown in Figures 3 and 5, the method of constructing a concrete wall against an existing wall comprises the steps of: • provide the formwork, in particular by lifting the uniwall using a crane 40 as shown in 6 and placing the crane against the existing wall 10, and then fixing the uniwall to the floor slab 9 by means of the L-shaped connectors 35 and the studs 29, 32 as shown in figures 7 and 8 respectively, • fill the space between the uniwall and the existing wall 10 with concrete 11. Concrete is a liquid concrete which will harden in the space between the uniwall and the existing wall 10.

[0045] As clearly shown in [Fig. 5], the step of filling the space between the uniwall and the existing wall 10 with concrete 11 comprises filling the space in stages. Each stage comprises filling the space to a predetermined height and waiting for a predetermined time to allow the concrete 11 poured at said stage to harden. This is shown in [Fig. 5] by means of the interfaces 53 which are formed between the concrete sections poured in different stages.

Claims

Claims

1. A precast reinforced concrete wall configured for use in a formwork for constructing a concrete wall against an existing wall (10), wherein the existing wall is part of the formwork and wherein the precast concrete wall is part of the concrete wall, wherein the precast concrete wall comprises a concrete slab (18) extending over a given "slab height" in a first direction (x), in use substantially parallel to the gravitational direction, from a lower portion (19) to an upper portion (21), and wherein the precast concrete wall further comprises at least one lattice beam (23), wherein the lattice beam comprises a lower elongated metal bar (24),an upper elongated metal bar (25) substantially parallel to the lower elongated metal bar and a wire mesh (26) connecting the lower elongated metal bar to the upper elongated metal bar, and wherein the lower elongated metal bar (24) is located inside the concrete slab while the upper elongated metal bar (25) is located outside the concrete slab such that the upper elongated metal bar is freely accessible by a user from a first side of the concrete slab, said side being called the inner side as opposed to the opposite side of the concrete slab which is called the outer side, and wherein a first row of stud connectors (31) is provided inside the concrete slab such that the stud connectors are accessible for releasably connecting the studs (32) to the concrete slab from the outer side of the concrete slab,characterized in that a punching reinforcement (49) is provided inside the concrete slab at the positions of the dowel connectors.,

2. A prefabricated wall according to claim 1, wherein the stud connectors are threaded sockets.

3. A prefabricated wall according to claim 1 or 2, wherein the first row of stud connectors extends substantially in a second direction substantially perpendicular to the first direction.

4. A precast wall according to claim 3, wherein the first row of stud connectors is positioned in the lower portion of the concrete slab, preferably below 50% of the height of the concrete slab, preferably below 40% of the height of the concrete slab, and preferably above 10% of the height of the concrete slab, preferably above 20% of the height of the concrete slab, preferably approximately 30% of the height of the concrete slab.

5. A precast wall according to any one of the preceding claims 1 to 3, wherein the first row of stud connectors is positioned in the upper portion of the concrete slab, preferably above 50% of the height of the concrete slab, preferably above 60% of the height of the concrete slab, and preferably below 90% of the height of the concrete slab, preferably below 80% of the height of the concrete slab, preferably approximately at 70% of the height of the concrete slab.

6. A precast wall according to claim 3, wherein a second row of stud connectors (28) is provided within the concrete slab such that the stud connectors are accessible for releasably connecting studs (29) to the concrete slab from the exterior side of the concrete slab, wherein the stud connectors are preferably threaded sockets, and wherein the second row of stud connectors preferably extends substantially in the second direction substantially perpendicular to the first direction.

7. A precast wall according to claim 6 in combination with claim 4, wherein the second row of stud connectors is positioned in the upper portion of the concrete slab, preferably above 50% of the height of the concrete slab, preferably above 60% of the height of the concrete slab, and preferably below 90% of the height of the concrete slab, preferably below 80% of the height of the concrete slab, preferably approximately at 70% of the height of the concrete slab.

8. Prefabricated wall according to any one of the preceding claims, wherein at least one L-profile connector (34), preferably implemented in the form of a socket threaded, is provided in the lower portion of the concrete slab adjacent a lower edge of the concrete slab and so as to be accessible from the exterior side of the concrete slab, wherein the L-shaped channel connectors are configured to releasably connect to an L-shaped channel (35).

9. A precast wall according to any preceding claim, wherein at least two lifting anchors (41) are provided within the upper portion of the concrete slab so as to be accessible from the inner side of the concrete slab, wherein the lifting anchors are configured to releasably connect to a crane hook so that the crane hook (40) can lift the concrete slab.

10. Prefabricated wall according to the preceding claim, wherein a lifting anchor arm connector, preferably implemented as a threaded sleeve, is provided inside the upper portion of the concrete slab and so as to be accessible from the outer side of the concrete slab, wherein the threaded sleeve is configured to removably connect to a lifting anchor arm (42) comprising an additional lifting anchor.

11. Prefabricated wall according to the preceding claim, wherein one of the stud connectors is simultaneously the lifting anchor arm connector.

12. A precast wall according to any preceding claim, wherein the precast concrete wall further comprises a concrete flow interruption grid (45) such as a "Stremaform ®" type grid connected to the concrete slab.

13. Prefabricated wall according to any one of the preceding claims in combination with claim 4, in which the punching reinforcement is a set of metal rods extending substantially in the second direction.

14. Prefabricated wall according to the preceding claim, wherein additional reinforcements are provided inside the concrete slab, wherein the additional reinforcements preferably comprise a first set of metal rods (50) extending substantially in the first direction, a second set of metal rods (51) extending substantially in the second direction, a third set of metal rods (52)

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23. extending substantially in the first direction, wherein the first, second and third sets are in different planes. Formwork for constructing a concrete wall against an existing wall (10), the formwork comprising the precast concrete wall according to any one of claims 1 to 14. Formwork according to the preceding claim, further comprising the existing wall (10). Formwork according to the preceding claim, in which the existing wall is an existing wall (10) made of concrete. Formwork according to any one of claims 16 and 17, wherein the existing wall (10) is an earth retaining wall, preferably forming a foundation or basement. Formwork according to the preceding claim, in which the earth retaining wall is a cutter soil mixing wall, a "Berlin" type wall, or a "pile" type wall. Formwork according to any one of claims 17 to 19, wherein the existing wall (10) is a Berlin-type earth retaining concrete wall, wherein a vibration damping layer is fixed to the existing wall in the space between the precast concrete wall and the existing wall (10), wherein the vibration damping layer is preferably a double-walled sheet such as a Biplex ® sheet. Formwork according to any one of claims 15 to 20, wherein the formwork further comprises studs removably connected to the stud connectors. Formwork according to any one of claims 15 to 21 in combination with claim 8, wherein the formwork further comprises one or more L-shaped sections, each being removably connected to one of the L-shaped section connectors. A method of constructing a formwork, the method comprising the steps of: providing a prefabricated wall according to any one of claims 1 to 14, creating the formwork according to any one of claims 15 to 22 by placing the prefabricated wall in such a way adjacent to an existing wall (10) so that the existing wall is on the inside of the concrete slab.

24. A method of constructing a concrete wall against an existing wall (10), the method comprising the steps of: • providing formwork by carrying out the method of claim 23, • filling the space between the precast wall and the existing wall (10) with concrete (11).

25. A method according to the preceding claim, wherein the step of filling the space between the precast wall and the existing wall (10) with concrete (11) comprises filling the space in stages, wherein each stage comprises filling the space to a predetermined height and waiting for a predetermined time to allow the concrete poured in said stage to harden.

26. A method according to claim 25, wherein the predetermined height and duration are such that the maximum horizontal pressure exerted by the concrete on the precast wall during each step is less than 50 kN / m2, preferably less than 30 kN / m2.

27. ​​A method according to any one of claims 25 and 26, wherein the predetermined height is less than 1.5 m, preferably less than 1 m, for example about 0.8 m for a predetermined duration of one hour.

28. A method according to any one of claims 25 to 27, wherein the concrete is a CEM I type concrete when the outside temperature at the installation site is below 15°C, and wherein the concrete is a CEM III type concrete when the outside temperature at the installation site is above 15°C.

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