FR3066514B1 - 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 primarily to the field of buildings and 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 filling may be a concrete, consisting of a mixture of aggregates of different sizes, cement and water. The invention particularly relates to the production of prefabricated assemblies for the production of structural webs to include an insulation on one side.

To achieve external thermal insulation that meets the latest standards, including the French standard RT 2020 (thermal regulation 2020), it is necessary to proceed to the laying on the structure of a thermal insulation of 20 to 30 cm minimum . This insulating complex must generally be covered by a finishing and protection siding. The weight of this facing (between 100 and 200 kg / m2) 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 is, and more this connection is difficult to achieve. For insulations smaller than 10 cm it is traditionally possible to directly fix the insulation on the structure by means of nails of 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 to be resumed, is high, which leads to expensive and unsustainable implementations because of the increased risks of creep of the fasteners under high forces. .

To meet the above requirements, the insulation is installed after the construction of the outer sails. According to this method, pegs are placed on the outer sails. Five brackets are usually used per square meter and four pegs per square. The wings dimension of these brackets is much greater than the thickness of the insulation; They perforate the insulation which is itself locked by a device, wooden or metal, itself fixed on the brackets. The siding (cladding, plaster or stone) is then attached to these locks.

These processes are implemented at height on construction sites, which introduces risks with regard to the safety of the workers; they are also long and expensive. Furthermore, the reported fasteners are not durable because subject to the creep phenomenon that leads in time to disorders, including the fall of siding.

According to another method, two thin reinforced concrete slabs connected by steel connectors are used. One of these slabs is provided in its inner part with an insulating complex. The free distance between the slabs is filled on the concrete site. Prefabricated elements and cast-in-place concrete all have a structural role, that is to say they participate together in descent of loads. This method nevertheless has the following drawbacks: the free distance to be filled on the construction site is low and poses filling problems despite the use of micro-concrete; the connectors constitute a mesh of thermal bridges which is detrimental to the insulation function; - The adhesion between prefabricated elements and cast concrete, which are of different age in nature, is not perfect, so that prefabricated elements and cast-in-place concrete form a "laminated" not allowing a transmission optimal efforts between them, by effect of connecting rods. - The filling must be done with a fluid concrete with very fluid. This requirement has the consequence of subjecting the formwork faces and particularly the internal insulator to a high hydrostatic pressure. To avoid the risk of slab failure and a weakening of the insulation characteristics, it is required 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 case 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 notably to propose an insulation method and an associated formwork device that makes it possible to meet the new thermal insulation standards, while providing a solution to all or some of the problems inherent in the processes of the prior art. .

According to the invention, such a formwork device lost to construct 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 a filtering and formwork inner wall fixed to said cage.

Such a device advantageously comprises, between the filtering wall and the insulating panel, a volume adapted to set up on site, all at once, a structural material in which the cage is intended to be substantially completely embedded.

Preferably, such a device comprises connectors for fixing the facing to the cage. Each connector may include a stem having a proximal member extending through the insulating panel and a caudal member, preferably forming a bend with the proximal member. In addition, each connector may comprise, at a free end of the proximal element, means for attaching, preferably by screwing, a hand, this hand being provided with means for pressing the insulating panel against the cage. Also, each connector may comprise, at a free end of the proximal element, means for attaching, preferably by screwing, a hand, the hand comprising means for attaching a reinforcement 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 non-limiting examples, with reference to the accompanying drawings in which: - Figure 1 is a perspective view, from its inner side, that is that is to say, its side intended to be directed towards the interior of the building to be constructed, of a formwork device according to the invention; - Figure 2 is an elevational view and profile of the form of the device of Figure 1; - Figure 3 is a sectional elevation and profile of the formwork 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 view, in perspective, of an inner wall and a main frame for the formwork device of Figure 1, as seen from the outside inside the building to be built; - Figure 6 is a detail view of the main frame of Figure 5; FIG. 7 is a perspective view of an insulating panel for the device of FIG. 1; - Figure 8 is a perspective view of a connector according to the invention for assembling the insulating panel and an outer facing with the main frame; FIG. 9 is an enlarged view of one end of the connector of FIG. 8; - Figure 10 is a detailed view of the assembly of the insulating panel and the outer facing with the main frame with connectors such as that shown in Figure 8; FIG. 11 is a detailed view of FIG. 10, in the vicinity of an end such as that illustrated in FIG. 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; FIG. 14 is a view from above of the upper edge, illustrating a method of horizontal relative positioning of two superposed facings; FIG. 15 illustrates an adjustment device for the method illustrated in FIG. 14; FIG. 16 illustrates a method of vertical relative adjustment of two superposed facings; and, FIG. 17 illustrates adjustment means for the method illustrated in FIG. 16.

Figures 1 to 3 illustrate a forming device 1 according to the invention. This device comprises, from the inside N to the outside E: - a facing 2; an insulating panel 3; a reinforcement cage 4; and, a formwork inner wall 5.

In the example shown: - the facing 2 is a finished facing, that is to say, it is intended to form the outer wall of a building constructed using the device 1, visible from the outside the building when finished; - The formwork inner wall 5 is a filter wall, intended to be dressed by an interior finishing trim, not shown in the figures. This facing may comprise plasterboard, or be a plaster, for example plaster or mortar, projected on the wall. Such a filtering wall is in particular known from document FR 3 015 995.

The device 1 is intended to be prefabricated in the factory and then delivered on site as illustrated in Figures 1 to 3. As shown in Figures 3 and 4, the device being positioned in the building structure of the building, a structural material 6 is cast 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 makes it possible to evacuate the excess water, thus reducing the hydrostatic pressure. The reduction of this pressure makes it possible in particular to protect the insulating panel from crushing, even partially, and thus, to preserve its structural and insulating qualities. The insulation 3 and the filtering wall 5 together form a formwork for the structural material. The distance between the insulator 3 and the filtering wall 5 defines the thickness E6 of the structural material thus encased. Preferably, the structural material is substantially homogeneous and cast at one time.

As particularly illustrated in Figures 5 and 6, the cage 4 comprises: - vertical scales 11, zigzag-shaped; a bed of anterior vertical ropes 12; a bed of horizontal horizontal ropes 13; a bed of posterior vertical threads 14; and, a bed of horizontal horizontal ropes 15;

In the illustrated example, the cages are made with reinforcing bars.

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 FIGS. 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 E6 thickness of the structural filling 6. In the illustrated example, the pitch is constant.

The anterior vertical threads 12 are fixed to the ladders, by welding or ligatures, at a distance D12 from the previous tops 17 of the ladders corresponding to a sufficient coating of these threads. The rear vertical threads 14 are fixed, by welding or ligatures, at a distance D14 from the posterior tops 18 of the scales corresponding to a sufficient coating of these threads. The anterior horizontal ropes 13 are attached to the vertical anterior ropes 12, by welding or ligatures, on the opposite side to the anterior vertices 17. The posterior horizontal ropes 15 are attached to the vertical uprights 12, by welding or ligatures, on the opposite side to the posterior apices 18.

The wall 5 is designed to be traversed from front to back by the posterior tops 18. A bed of horizontal threads 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 attached to at least one ladder 11, by welding or ligatures, in order to make a positive assembly inside the loop formed by an apex 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 at the rear of the wall 5, that is to say the inner side N of the device. The locks are made of a resistant material, for example made of composite material or of a steel which has received 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 to 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 are taken. This arrangement is intended to pass the structural material from the fluid phase, during its implementation, to the solid phase, by solid contact of the solid elements together after total percolation. The dimensions of these orifices and wires are calculated to meet the laws relating to "solid-atmosphere-liquid" equilibria.

The insulation board has a density adapted to the type of insulation, sought, whether thermal and / or acoustic. The material is preferentially water-repellent; its composition is generally chosen in a closed cell. Its thickness depends on the targeted performances. Preferably produced in a single panel whose width and height are chosen so that when laying the device according to the invention, it can be placed substantially joined with the neighboring device panels by interlocking the respective rabbets between them, so that the insulation is continuous on all the wall thus manufactured.

As particularly illustrated in Figure 7, the slices of the insulating panel 3 are in the form of rabbets 21 for reciprocal engagement of the panel with a neighboring panel, to achieve a better continuity of insulation between two adjacent devices. In the example illustrated, each portion of the insulating panel 3 further forms a channel 22, set back from the rest of the wafer; this gutter has the role of evacuating 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 Figures 10 and 11, the facing 2 is connected to the cage 4 by connectors 24 passing through the insulating panel 3. As shown in Figure 8, each connector 24 comprises a bent rod 25 and a hand 26. The bent rod comprises a right caudal element 27 and a proximal right element 28, interconnected by a bend 29 so that the straight elements 27,29 form between them an angle substantially equal to 90 degrees. In the illustrated example, the three elements are formed of a piece in the same concrete iron. One end 31 of the proximal member 28, opposite the elbow 29, is threaded; the hand 26 is attached by screwing on this threaded end 31.

As illustrated in Figure 7, the insulating panel 3 comprises a set of cylindrical passages, passing through its thickness. Each passage is disposed 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 with a horizontal plane a non-zero angle. In the illustrated example, the passages are arranged in staggered rows and alternately form an angle A3 2 positive or negative with said horizontal plane. The passages 32 have a chosen diameter 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 outside E, so that the hand can be screwed there; on the other side of the insulating panel, this proximal element is fixed to a scale 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 D11 between two adjacent ladders, 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 outside E and the structural part 6; the hand thus guarantees a continuity of insulation provided by the insulating panel 3.

The hand can be made in one or more pieces. In the illustrated example, the hand comprises, from the front to the back, that is to say, then the outside E inward N: - a base 41; a cylindrical body 42; a flange 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 tapping, so that it is intended to be screwed onto the threaded end 31. The cylindrical boss comprises on its rear face a notched chamfer (46) for boring the insulating panel, during installation by screwing of the hand 26.

The flange 43 is fixed relative to the body 42. It has a shape going flaring back and forth. In the example shown, the cap has a truncated sphere shape. That truncated sphere shape ensures a tightness of the insulating panel 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 the collar. It comprises a ribbed rear end which makes it possible to machine a counter-free countersink 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 forwardly from the base 41, that is to say in a direction opposite to that of the proximal element of the bent rod. In the illustrated example, the fingers are mounted and fixed by a harpoon effect in orifices 51 provided for this purpose in the base. These orifices are here twelve in number, distributed in a circle on the base, so that the position of the fingers can be selected from several available.

The fingers comprise notches 52, arranged so that a finger has a notch facing the notch of a neighboring finger, so that an iron 35 of the reinforcement of the facing 2 can be snap-fastened. 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 lattice, 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 reference for the realization of a visible face 55 of the facing 2, thus determining, at the less locally, a thickness L2 of this facing. The free end 53 of the finger can be screwed or unscrewed into the rest of the finger 49; which allows to adjust the length. The notched boss 44 creates a countersink in the insulating panel, until the spherical flange 43 abuts on the face 45 of the insulating panel 3 and the latter is in abutment against the anterior peaks 17 of the cage 4. The boss 44 being encased in the insulating panel 3, calories (or frigories) can not circulate between the facing bent rod connectors 24, usually steel, which will themselves be embedded in the structural concrete 6 cast on site. In a device 1 according to the invention, not all hands necessarily include a long finger 49; indeed, when the visible face of the facing is flat, three long fingers are sufficient to define the plane. When a hand does not include a long finger, it then includes four short fingers.

Thus, the hand 26 according to the invention has among its many functions: - a thermal break; the positioning of the armature 35 of the facing 2; - Fixing this frame 35; - a mark for the thickness of the facing. - the resumption of the weight of the facing and its transmission to the structural part 6; and, - the resumption of efforts on the facing and their transmission to the structural part 6.

Cladding 2 has a function of protecting the insulation and aesthetic covering. In the example illustrated in Figures 10 and 11, the facing 2 has a thickness of between four and eight centimeters; it is made of reinforced microbeton.

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

Thus, to produce a device according to the invention, one can use the following method: - the reinforcement cage 4 is disposed, preferably horizontally on the insulating panel 3; - Just smaller diameter passages 32 than the connectors 24 are drilled in the thickness of the insulating panel, preferably with an alternately positive or negative angle, preferably close to 45 0; the bent rods of the connectors 24 are introduced into the passages and are fixed on the ladders 11; - The hands 26 are fixed on the end 31 of the bent rods so that the insulating panel 3 bears on the ladders 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 cast respecting the external level indicated by the long fingers 49.

Reservations and lifting sleeves are advantageously introduced into the facing during its casting, according to techniques known to those skilled in the art.

Methods of adjustment of the device will now be described, when it is laid 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 susceptible to dimensional variations. The face 55 may also have facade patterns that should be aligned with those located on neighboring panels already in place.

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

As illustrated in FIGS. 12 to 14, which schematize the principle of the adjustment in horizontal coordinates, the top edge 60 of a facing 2 comprises two first oblong holes 61, extending parallel to the visible face 55, each formed close to a respective vertical trance 64, and a third oblong hole 62 disposed between the two perpendicularly to the visible face 55.

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

In the example shown, the upper edge comprises two spherical supports 74, each in the vicinity of a respective vertical slice 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 laying. 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 to the bottom, so that no load is transmitted by a facing facing it is inferior.

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

The top edge 60 of the facing comprises at least one sleeve 76 sealed in the facing 2. This sleeve is provided for screwing a ball bearing slidingly mounted on a shaft. Spreading means, fixed to the ball joint, make it possible to adjust the verticality of the visible face 55.

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 flat but, for example, cylindrical.

The insulation board and the hands frequently have a low melting point, for example 160 ° C. Thanks to the provisions of the invention, including the alternating inclination of connectors, in case of fire, the disappearance of the insulating wall has no consequences affecting the safety of personnel in charge of the management of this disaster. Unlike the methods traditionally used, the facing is not fixed by elements reported on the structure, for example by dowels; on the contrary, it is sealed in the structural filling by metal elements which guarantee a durable attachment or which, at least, significantly delays the risk of ruin of a wall built with a device according to the invention. This positive fixation is achieved by the recovery of 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 siding also makes it possible to separate this facing from those immediately below. This arrangement also has the advantage of expanding the range of choices for the insulating material since the mechanical strength of the latter does not affect 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 during the filling of 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 meet in particular the disadvantages of the methods of the prior art; it allows in particular: - a strong reduction of the hydrostatic pressure resulting from the filling, - a perfect transmission of the charges in the structural part of the wall, cast at one time with a substantially homogeneous material; a clipping of the outer facing by connectors positively connected to the structure, elimination of the thermal bridges due to the connectors, reduction of the weight of the prefabricated elements, an incorporated adjustment of the prefabricated faces which allows greater manufacturing tolerances, - an increase in safety in case of fire

Claims (8)

claims 1. Device (1) of formwork lost to construct a wall of a building, characterized in that it comprises, from the outside (E) inward (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). 2. Device (1) according to claim 1, characterized in that it comprises between the filtering wall (5) and the insulating panel (3) a volume adapted to set up on site, at once, a structural material wherein the cage (4) is provided to be substantially completely embedded. 3. Device (1) according to 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, a proximal element (28) through the insulating panel and a caudal element (27), preferably forming a bend with the proximal element. 5. Device (1) according to claim 4, characterized in that each connector (24) comprises, at a free end (31) of the proximal element (28), means for fixing, preferably by screwing, a hand (26), said hand comprising means (43) for pressing the insulating panel against the cage (4). 6. Device (1) according to claim 4, characterized in that each connector (24) comprises, at a free end (31) of the proximal element (28), means for fixing, preferably by screwing, a hand (26), said hand comprising means (48,49) for attaching an armature (35) for the facing (2). 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.