FR3066514A1 - LOST INSULATED FORMWORK AND ASSOCIATED METHOD FOR MAKING A WALL. - Google Patents

Abstract

Apparatus (1) of formwork lost to construct a wall of a building, comprising, from the outside (E) towards the interior (N) of said building: - a facing (2); an insulating panel (3); - an armature cage (4); and, a filtering and formwork inner wall (5) fixed to said cage (4). Such a device is particularly suitable for implementing an insulating panel of great thickness.

Description

The present invention relates mainly to the field of buildings and engineering structures. It relates more particularly to the field of formwork, and more generally to any field for which an empty volume must be filled with a filling, this filling being a mixture of solid materials and a fluid. Such a filling can be a concrete, consisting of a mixture of aggregates of different dimensions, cement and water. The invention relates particularly to the production of prefabricated assemblies allowing the production of structural sails to have insulation on one side.

To achieve external thermal insulation that meets the most recent standards, in particular the French standard RT 2020 (thermal regulation 2020), it is necessary to install a thermal insulation of at least 20 to 30 cm on the structure . This insulating complex must generally be covered by a finishing and protective facing. The weight of this facing (between 100 and 200 kg / m ² ) must be transmitted to the supporting structure. It is very easily understood that the greater the thickness of the insulation, the greater the moment exerted by the facing on the structure, and the more difficult this connection is to achieve. For insulation smaller than 10cm, it is traditionally possible to fix the insulation directly on the structure by means of nails with a horizontal axis which are pegged to the structure and have a thermal break device. On the other hand, for insulations greater than 10 cm, the value of the moment, and therefore of the forces at

-2 to resume, is high which leads to expensive and unsustainable implementations due to the increased risks of creep of the fasteners under high forces.

To meet the above requirements, insulation is installed after the construction of the exterior sails. According to this process, anchor squares are placed on the outer sails. Generally five brackets are used per square meter and four dowels per square. The dimension of the wings of these brackets is much greater than the thickness of the insulation; They perforate the insulation which is itself locked by a device, in wood or metal, itself fixed on the brackets. The facing (cladding, plaster or stone) is then attached to these locks.

These processes are implemented at height on construction sites, which introduces risks to the safety of workers; they are also long and expensive. Furthermore, the attached fasteners are not durable because subject to the creep phenomenon which leads over time to disorders, in particular to the fall of facing.

According to another method, two thin reinforced concrete slabs are used connected by steel connectors. One of these tiles has an insulating complex in its interior. The free distance between the slabs is filled on the concrete site. The precast elements and the concrete poured in place all have a structural role, that is to say that they participate together in the descent of the loads. This process nevertheless has the following drawbacks:

- the free distance to be filled on the construction site is small and poses filling problems despite the use of micro-concrete;

- the connectors constitute a mesh of thermal bridges harmful to the insulation function;

- the adhesion between the prefabricated elements and the poured concrete, which are of different ages by nature, is not perfect, so that the prefabricated elements and the concrete poured in place form a "laminate" not allowing a transmission optimal efforts between them, by effect of connecting rods.

- filling must be carried out with a fluid to very fluid concrete. This requirement has the consequence of subjecting the formwork faces and particularly the internal insulation to a high hydrostatic pressure. To avoid the risks of rupture of the slabs and a weakening of the insulation characteristics, it is requested to limit the filling height; typically, the maximum height is seventy centimeters to one meter, which significantly slows the site;

- the weight of the sets is important;

- there are risks for the security services in the event of fire;

- the continuity of the steels in a horizontal plane can only be achieved in the free space very close to the neutral axis of the structural part;

- the prefabricated slabs have finished faces which do not allow any adjustment made necessary by the manufacturing and implementation tolerances.

The object of the invention is in particular to propose an insulation method and an associated formwork device making it possible to meet the new standards of thermal insulation, while providing a solution to all or part of the problems inherent in the methods of the prior art. .

According to the invention, such a lost formwork device for constructing a wall of a building, is characterized in that it comprises, from the outside to the inside of said building:

- a facing;

- an insulating panel;

- a reinforcement cage; and,

- an inner filtering and shuttering wall, fixed to said cage.

Such a device advantageously comprises, between the filtering wall and the insulating panel, a volume suitable for placing on site, at one time, a structural material in which the cage is intended to be substantially entirely embedded.

Preferably, such a device comprises connectors for fixing the facing to the cage. Each connector may comprise a rod, a proximal element of which passes through the insulating panel and a caudal element, preferably forming an elbow with the proximal element. In addition, each connector may comprise, at a free end of the proximal element, means for fixing therein, preferably by screwing, a hand, this hand being provided with means for pressing the insulating panel against the cage. Also, each connector can comprise, at a free end of the proximal element, means for fixing there, preferably by screwing, a hand, this hand comprising means for fixing there an armature for the facing.

The invention also relates to a formwork system comprising several devices according to the invention.

The invention also relates to a method of constructing an insulating wall, characterized in that it uses at least one device according to the invention.

Several embodiments of the invention will be described below, by way of nonlimiting examples, with reference to the accompanying drawings in which:

- Figure 1 is a perspective view, from its inner side, that is to say its side intended to be directed towards the interior of the building to be constructed, of a shuttering device according to the invention;

- Figure 2 is an elevational view in profile of the shuttering device of Figure 1;

- Figure 3 is a sectional elevation and profile of the shuttering device of Figure 1, before pouring a filling concrete;

- Figure 4 is a section similar to that of Figure 3, after pouring the filling concrete;

- Figure 5 is a partial perspective view of an inner wall and a main frame for the shuttering device of Figure 1, as seen from outside the interior of the building to be constructed;

- Figure 6 is a detail view of the main frame of Figure 5;

- Figure 7 is a perspective view of an insulating panel for the device of Figure 1;

- Figure 8 is a perspective view of a connector according to the invention, provided for assembling the insulating panel and an outer facing with the main frame;

- Figure 9 is an enlarged view of one end of the connector of Figure 8;

- Figure 10 is a detail view of the assembly of the insulating panel and the outer facing with the main frame using connectors such as that illustrated in Figure 8;

- Figure 11 is a detail view of Figure 10, in the vicinity of an end such as that illustrated in Figure 9;

- Figure 12 is a perspective view, from below, of a lower edge of the facing;

- Figure 13 is a perspective view, from above, of an upper edge of the facing;

- Figure 14 is a top view of the upper edge, illustrating a method of horizontal relative positioning of two superimposed facings;

- Figure 15 illustrates an adjustment device for the method illustrated in Figure 14;

- Figure 16 illustrates a method of vertical relative adjustment of two superimposed facings; and,

FIG. 17 illustrates adjustment means for the method illustrated in FIG. 16.

Figures 1 to 3 illustrate a shuttering device 1 according to the invention. This device comprises, from inside N to outside E:

- a facing 2;

- an insulating panel 3;

- a reinforcement cage 4; and,

- an inner formwork wall 5.

In the example shown:

- the facing 2 is a finished facing, that is to say that it is intended to form the outer wall of a building constructed using the device 1, visible from the outside of the building when it is finished ;

- The shuttering interior wall 5 is a filtering wall, intended to be covered by an interior finishing covering, not illustrated in the figures. This facing may include plasterboard, or be a coating, for example plaster or mortar, projected onto the wall. Such a filtering wall is known in particular from document FR 3 015 995.

The device 1 is intended to be prefabricated in the factory and then delivered to the site as illustrated in Figures 1 to 3. As illustrated in Figures 3 and 4, the device being positioned in the structure under construction of the building, a material

-7 structural 6 is poured between the insulating panel 3 and the inner wall 5, so that the cage 4 is substantially embedded in the structural material. This material 6 is preferably a hydraulic concrete; the filtering wall allows excess water to be evacuated, thereby reducing the hydrostatic pressure. The reduction in this pressure makes it possible in particular to protect the insulating panel from being crushed, even partially, and thus to preserve its structural and insulating qualities. The insulator 3 and the filter wall 5 together form a formwork for the structural material. The distance between the insulator 3 and the filter wall 5 defines the thickness E6 of the structural material thus enclosed. Preferably, the structural material is substantially homogeneous and poured in one go.

As particularly illustrated in FIGS. 5 and 6, the cage 4 comprises:

- vertical scales 11, in the form of a zigzag;

- A bed of anterior vertical streaks 12;

- A bed of anterior horizontal streaks 13;

- a bed of rear uprights 14; and,

- a bed of rear horizontal lines 15;

In the example illustrated, the cages are made with concrete irons.

The scales are arranged in vertical planes substantially perpendicular to a general plane of the wall under construction using the device 1, that is to say in a plane parallel to the plane of Figures 2 to 4 and 6. Each scale 11 consists of a single continuous wire, over the entire height of the cage 4, with a “Z” profile with constant or variable pitch, depending on the shape of the final veil to be obtained and whose height between the vertices 17, 18 determines the thickness E6 of the structural filling 6. In the example illustrated, the pitch is constant.

The front vertical strings 12 are fixed to the ladders, by welding or tying, at a distance D12 from the front vertices 17 of the ladders

-8 corresponding to a sufficient coating of these streaks. The rear vertical lines 14 are fixed, by welding or tying, at a distance D14 from the rear vertices 18 of the scales corresponding to a sufficient coating of these lines. The front horizontal lines 13 are fixed to the front vertical lines 12, by welding or ligatures, on the side opposite to the front vertices 17. The rear horizontal lines 15 are fixed to the vertical rear lines 12, by welding or ligatures, on the side opposite to the rear vertices 18.

The wall 5 is designed to be crossed from front to rear by the rear vertices 18. A bed of horizontal struts forming locks 16 for the filtering wall 5 is used to fix the wall to the cage 4. The locks 16 are arranged between the posterior tops 18 and the wall; they are fixed to at least one ladder 11, by welding or ligatures, in order to produce a positive assembly inside the loop formed by a vertex 18. Thus, the wall 5 is kept locked on the cage 4, in particular under the effect of the pressure of the structural material during filling. The posterior tops 18 and the latches are visible behind the wall 5, that is to say on the interior side N of the device. The locks are made of a resistant material, for example a composite material or a steel having received a durable surface protection, insensitive to corrosion phenomena

In the example illustrated, the filtering wall 5 forms a matrix of orifices. This wall is designed to resist without excessive deformation the filling of the device 1 with the structural material 6. The size of the orifices is defined to contain the solid elements of the structural material. These solid elements constituting a percolating vault for the fluid elements of the structural material, before they set. The purpose of this arrangement is to pass the structural material from the fluid phase, during its implementation, to the solid phase, by solid contact of the solid elements with each other after total

-9percolation. The dimensions of these orifices and of the wires are calculated to meet the laws relating to “solid-atmosphere-liquid” balances.

The insulating panel has a density adapted to the type of insulation sought, whether thermal and / or acoustic. The material is preferably water repellent; its composition is generally chosen in a closed cell. Its thickness depends on the targeted performance. Preferably produced in a single panel whose width and height are chosen so that during the installation of the device according to the invention, it can be placed substantially contiguous with the neighboring device panels by interlocking the respective rebates together, so that the insulation is continuous over the entire wall thus produced.

As particularly illustrated in FIG. Ί, the edges of the insulating panel 3 are in the form of rebates 21 allowing a reciprocal interlocking of the panel with an adjacent panel, in order to achieve better continuity of the insulation between two neighboring devices. In the example illustrated, each edge of the insulating panel 3 further forms a gutter 22, set back from the rest of the edge; the purpose of this gutter is to evacuate any rainwater and / or condensate. Preferably, an outlet is formed between the gutter of the lower edge and a front face of the insulating panel.

As illustrated in FIGS. 10 and 11, the facing 2 is connected to the cage 4 by connectors 24 passing through the insulating panel 3. As illustrated in FIG. 8, each connector 24 comprises a bent rod 25 and a hand 26. The bent rod comprises a right caudal element 27 and a right proximal element 28, connected together by an elbow 29 so that the straight elements 27, 29 form an angle between them substantially equal to 90 degrees. In the example illustrated, the three elements are formed in one piece in the same concrete reinforcement. A

-10 end 31 of the proximal element 28, opposite the elbow 29, is threaded; the hand 26 is added by screwing onto this threaded end 31.

As illustrated in FIG. 7, the insulating panel 3 comprises a set of cylindrical passages, passing through it according to its thickness. Each passage is arranged in a vertical plane P32 perpendicular to the general plane of the device, that is to say parallel to the plane of Figures 2 to 4. Each passage forms a non-zero angle with a horizontal plane. In the example illustrated, the passages are arranged in staggered rows and alternately form a positive or negative angle A3 2 with said horizontal plane. The passages 32 have a diameter chosen smaller than the diameter of the proximal element 28 of the connector 24.

As illustrated in FIG. 10, the proximal element 28 of each connector is introduced into a respective passage 32, so that its threaded end 31 is accessible at the front of the insulating panel 3, that is to say on the side outside E, so that the hand can be screwed into it; on the other side of the insulating panel, this proximal element is fixed to a ladder 11 of the cage 4. Furthermore, the caudal element 27 is disposed substantially horizontally in the cage 4; the length L27 of this caudal element is preferably greater than the horizontal pitch Dll between two neighboring scales, for a better grip of the connector in the structural part of the wall under construction.

The hand 26 is made of a weakly conductive material, in order to ensure a thermal break between the exterior E and the structural part 6; the hand thus guarantees continuity of the insulation provided by the insulating panel 3.

The hand can be made in one or more pieces. In the example illustrated, the hand includes, from front to back, that is to say, then outside E towards inside N:

- a base 41;

- a cylindrical body 42;

- a collar 43; and,

- a cylindrical boss 44, in the extension of the body 42.

The base 41 is blind, so as to close the cylindrical body and thus provide insulation. The body comprises a thread, so that it is designed to be screwed onto the threaded end 31. The cylindrical boss comprises on its rear face a notched chamfer (46) making it possible to bore the insulating panel, during installation by hand screwing 26.

The collar 43 is fixed relative to the body 42. It has a shape which widens from back to front. In the example illustrated, the cap has the shape of a truncated sphere. This shape of a truncated sphere ensures that the insulating panel is clamped against the cage 4, despite the inclination of the proximal element 28, relative to the vertical outer surface 45 of the insulating panel.

The boss 44 is fixed relative to the body and to the collar. It includes a ribbed rear end which allows a backlash to be machined without play in the insulating panel during the screwing of the hand on the end 31 of the bent rod.

The hand further includes fingers 48,49. These fingers extend forward from the base 41, that is to say in a direction opposite to that of the proximal element of the bent rod. In the example illustrated, the fingers are mounted and fixed by a harpoon effect in holes 51 provided for this purpose in the base. These holes are twelve in number here, distributed in a circle on the base, so that the position of the fingers can be chosen from several available.

-12The fingers have notches 52, arranged so that a finger has a notch facing the notch of a neighboring finger, so that an iron 35 of the armature of the facing 2 can be fixed there by snap-fastening. The fingers are arranged so that two irons perpendicular to each other can be fixed between the four fingers, each snapped between two pairs of fingers. Thus, held by the hands, the frames 35 form a trellis, positioned so that their coating is sufficient. This arrangement also prevents any rotation of the hand, blocked by the frames, making the assembly foolproof.

In the example illustrated, the hand comprises a finger 49 longer than the other fingers 48. The free end 53 of this long finger 49 forms a mark for the production of a visible face 55 of the facing 2, thus determining, at less locally, a thickness L2 of this facing. The free end 53 of the finger can be screwed or unscrewed in the rest of the finger 49; which allows you to adjust the length. The notched boss 44 creates a countersink in the insulating panel, until the spherical collar 43 is in abutment on the face 45 of the insulating panel 3 and the latter is in abutment against the anterior tops 17 of the cage 4. The boss 44 being embedded in the insulating panel 3, calories (or frigories) cannot circulate between the facing the bent rod of the connectors 24, generally made of steel, which will themselves be embedded in the structural concrete 6 poured on the site. In a device 1 according to the invention, all the hands do not necessarily have a long finger 49; indeed, when the visible face of the facing is flat, three long fingers are enough to define the plane. When a hand does not include a long finger, it then includes four short fingers 48.

Thus, the hand 26 according to the invention has in particular among its many functions:

- a thermal break;

- the positioning of the frame 35 of the facing 2;

- The fixing of this frame 35;

- a benchmark for the thickness of the facing.

- the resumption of the weight of the facing and its transmission to the structural part 6;

and,

- resumption of efforts on the facing and their transmission to the structural part 6.

The facing 2 has a function of insulation protection and aesthetic covering. In the example illustrated in FIGS. 10 and 11, the facing 2 has a thickness of between four and eight centimeters; it is made of reinforced concrete.

Preferably, the facing 2 is cast flat on a horizontal shuttering table, its visible face 55 being shuttered by the table. The concrete intended to form the facing is first poured on the table, then a set comprising the cage 4, the panel 3, the connectors 24 and the frames 35, is lowered towards the table, hands 26 down, until that the ends 53 of the long fingers 49 abut against the table.

Thus, to make a device according to the invention, the following method can be used:

- the reinforcement cage 4 is arranged, preferably horizontally on the insulating panel 3;

- Passages 32 of diameter just smaller than that of connectors 24 are drilled in the thickness of the insulating panel, preferably with an alternately positive or negative angle, preferably close to 45 ^° ;

- the angled rods of the connectors 24 are introduced into the passages and are fixed to the scales 11;

- The hands 26 are fixed on the end 31 of the bent rods so that the insulating panel 3 comes to bear on the scales by machining a substantially sealed bore in the insulating panel; then,

reinforcements 35 are fixed in substantially orthogonal directions between the fingers 48, 49,

the facing 2 is poured while respecting the external level identified by the long fingers 49.

Reservations and lifting sleeves are advantageously introduced into the facing when it is poured, according to techniques known to those skilled in the art.

We will now describe methods of adjusting the device, during its installation on site, before filling with the structural material, with reference to FIGS. 12 to 17.

Despite manufacturing precautions, the dimensions of the visible face 55 are liable to dimensional variations. The face 55 may also have facade patterns which should best be aligned with those located on the neighboring panels already in place.

In the example illustrated, each facing is designed so that it can withstand without significant deformation, within reasonable limits and during the laying time, the weight of a facing which is superimposed on it. Thus the adjustment of a facing 2 during installation can thus be carried out with reference to the visible face 55 of the facing which is immediately below it. This adjustment is first made in coordinates then in tilt.

As illustrated in FIGS. 12 to 14, which show schematically the principle of adjustment in horizontal coordinates, the upper edge 60 of a facing 2 comprises

- 15two first oblong holes 61, extending parallel to the visible face 55, each formed near a respective vertical trance 64, and a third oblong hole 62 disposed between the two perpendicular to the visible face 55.

The lower edge 66 of the facing further comprises three sockets 68 of seals in the facing. In each of the sockets, a pivot 71 is screwed with a respective eccentric 70. Each socket 68 is complementary to a respective oblong hole 61, 62 of the upper edge of a lower facing, so that a cam 72 of the respective eccentric 70 can be housed in the corresponding oblong hole 61.62. The displacement of the cams around their respective pivot allows the adjustment of the horizontal coordinates of the facing during installation.

In the example illustrated, the upper edge comprises two spherical supports 74, each in the vicinity of a respective vertical edge 65. Each spherical support 74 can be screwed along a vertical axis, so that it allows the height adjustment of the position of the upper facing during installation. This arrangement also makes it possible to adjust the parallelism and the height of the joint between the two superimposed facings. The spherical supports are provisional. Thus, when the structural concrete 6 has set, the supports 74 are screwed in fully, so that no load is transmitted by a facing to the facing which is lower there.

FIGS. 16 and 17 illustrate the adjustment of the verticality of the visible face 55.

The upper edge 60 of the facing includes at least one socket 76 sealed in the facing 2. This socket is provided for screwing a spherical bearing slidably mounted on a shaft. Spreading means, fixed to the ball joint, allow the verticality of the visible face 55 to be adjusted.

Of course, the invention is not limited to the examples which have just been described.

Thus, the facing of a device according to the invention may not be planar but, for example, cylindrical.

The insulating panel and the hands frequently have a low melting point, for example 160 ° C. Thanks to the provisions of the invention, in particular the alternating inclination of the connectors, in the event of a fire, the disappearance of the insulating wall has no consequences affecting the safety of the personnel in charge of managing this incident. Unlike the traditionally used methods, the facing is not fixed by elements added to the structure, for example by ankles; on the contrary, it is sealed in the structural filling by metallic elements which guarantee a lasting fixing or which, at least, significantly delays the risks of ruin of a wall constructed with a device according to the invention. This positive fixation is achieved by covering steels in a mineral matrix which greatly delays its ruin. In addition, the three-dimensional arrangement of the connectors that connect the structural concrete elements and the facing also makes it possible to separate this facing from those immediately below. This arrangement also has the advantage of widening the range of choice for the insulating material since the mechanical resistance of the latter has no effect on the mechanical behavior of the assembly. This aspect is reinforced by the filtering nature of the filtering wall which makes it possible to lower the value of the hydrostatic pressure when filling the structural volume and limits the risk of compromising, by compression, the insulation characteristics of the insulation.

The use of a device makes it possible to respond in particular to the drawbacks of the methods of the prior art; it allows in particular:

- a large reduction in hydrostatic pressure resulting from filling,

- perfect load transmission in the structural part of the wall, poured in one go with a substantially homogeneous material;

- an attachment of the external facing by connectors positively linked to the structure,

- elimination of thermal bridges due to connectors,

- reduction of the weight of the prefabricated elements,

- an incorporated adjustment of the prefabricated faces which allows larger manufacturing tolerances,

- increased safety in the event of fire

Claims (8)

claims 1. Lost formwork device (1) for constructing a wall of a building, characterized in that it comprises, from outside (E) to inside (N) of said building: - a facing (2); - an insulating panel (3); - a reinforcement cage (4); and, - an inner filtering and shuttering wall (5), fixed to said cage (4). 2. Device (1) according to claim 1, characterized in that it comprises, between the filtering wall (5) and the insulating panel (3), a volume suitable for placing on site, in one go, a structural material wherein the cage (4) is intended to be substantially entirely embedded. 3. Device (1) one of claims 1 or 2, characterized in that it comprises connectors (24) for fixing the facing (2) to the cage (4). 4. Device (1) according to claim 3, characterized in that each connector (24) comprises a rod of which a proximal element (28) passes through the insulating panel and a caudal element (27), preferably forming an elbow with the proximal element. 5. Device (1) claim 4, characterized in that each connector (24) comprises, at a free end (31) of the proximal element (28), means for fixing there, preferably by screwing, a hand (26), said hand comprising means (43) for pressing the insulating panel against the cage (4). 6. Device (1) claim 4, characterized in that each connector (24) comprises, at a free end (31) of the proximal element (28), means for fixing there, preferably by screwing, a hand (26), said hand comprising means (48,49) for fixing an armature (35) to the facing (2). 5 7. Formwork system, characterized in that it comprises several devices (1) according to one of claims 1 to 6. 8. A method of constructing an insulating wall, characterized in that it uses at least one device according to one of claims 1 to 6.