FR3061221A1 - OUTDOOR THERMAL INSULATION SYSTEM CONSISTING OF HIGHLY INSULATING PROJECTED MORTAR - Google Patents

Abstract

The present invention relates to a thermal insulation system from the outside of a wall which comprises: - at least one non-metallic three-dimensional structural reinforcement element (E) formed of cavities or voids and of a fixed part on the wall (8) to be insulated, - at least one layer of thermally insulating mortar filling all the cells or voids of the reinforcing element and - at least finishing elements.

Description

Holder (s):

SAINT-GOBAIN WEBER.

O Extension request (s):

® Agent (s): SAINT GOBAIN RECHERCHE Société anonyme.

® THERMAL INSULATION SYSTEM FROM THE OUTSIDE CONSISTING OF A HIGHLY INSULATING SPRAYED MORTAR.

FR 3,061,221 - A1 (57) The present invention relates to a system for thermal insulation from the outside of a wall which comprises:

- at least one non-metallic three-dimensional structural reinforcement element (E) formed of cells or empty spaces and of a part fixed to the wall (8) to be insulated,

at least one layer of thermally insulating mortar filling all of the cells or empty spaces of the reinforcing element, and

- at least finishing elements.

EXTERIOR THERMAL INSULATION SYSTEM CONSISTING OF HIGHLY INSULATING PROJECTED MORTAR.

The present invention relates to a thermal insulation system from outside (ITE) using a highly insulating mortar filling a mechanical reinforcement grid.

Exterior thermal insulation is a solution currently widely used in the construction sector, both in renovation and in new construction. There are several types of thermal insulation from the outside. The most common systems on the market today use rigid insulating panels glued to the support in accordance with a regulated layout plan. These panels are based on expanded polystyrene, possibly with the addition of graphite, based on phenolic or polyurethane foam, based on mineral wool such as glass wool or rock wool, or based on cork or any other known material. for its insulating properties. On these insulating panels, it is necessary to apply a base plaster (or reinforcing plaster) reinforced with a grid or lattice to which a finishing plaster is then applied to provide the necessary protection and the aesthetic appearance. These systems are complex and are known as ETICS (External Thermal Insulating Composite System). Their advantage is in particular to offer a wide range of accessible thermal performance since the thermal conductivities of the insulating panels range from 12 mW / m.K for the insulating panels under vacuum to 130 mW / m.K. for certain OSB (Oriented Strand Board) chipboards. The panels based on expanded polystyrene or based on mineral wool conventionally have a thermal conductivity of the order of 35 mW / m.K. On the other hand, these rigid panels, once glued to the support, have the advantage of being mechanically strong enough to support the weight of undercoats as well as topcoats or paints. However, the addition of heavy siding such as ceramic tiles, cut stones or glass panels is strictly regulated in terms of surface weight limit per square meter and in terms of the height of building structures.

More recently, other types of exterior insulation system based on sprayed mortars have been developed. These mortars are based on lightening charges such as, for example, expanded polystyrene beads, perlite beads, expanded glass beads or aerogels. They are projected onto the support to be coated, with specific projection machines. These types of systems make it possible to avoid the layout phase of the layout plan, the rectification phase of the flatness of the support, in particular of the old supports in the event of renovation, and also the bonding phase of the insulating panel. However, the thermal performance of projected mortars depends severely on their density. To lower the value of the thermal conductivity of a sprayed mortar, it is necessary to lower its density and therefore use large quantities of lightening charges, and also foaming agents and / or air entrainers. The drop in density leads to a drastic decrease in the mechanical performance of these products, and therefore a lower load-bearing capacity vis-à-vis the finishing facings.

We are therefore looking for a solution that combines both performance in terms of thermal insulation and mechanical resistance. This is the framework of the present invention, which provides a system for thermal insulation of a wall in which the mechanical reinforcement and the thermal properties are provided by two different elements associated with each other. The present invention also provides a method of manufacturing said insulating system.

An object of the invention relates to a thermal insulation system for a wall which comprises:

- at least one non-metallic three-dimensional structural reinforcement element formed of cells or empty spaces and of a part fixed to the wall to be insulated,

- at least one layer of thermally insulating mortar filling all of the cells or empty spaces of the reinforcing element and

- to me of finishing elements.

Thus, the reinforcing element makes it possible to obtain the mechanical strength and the layer of mortar makes it possible to obtain the expected thermal insulation performance. It therefore becomes possible, thanks to the structural reinforcement element, to use mortars, in particular mineral ones, having very low density, and consequently very low thermal conductivity. When we talk about mineral mortars, we understand mixtures of binders such as cements and lime, extracts of natural materials, silico-limestone fillers and inert pigments, additives and adjuvants. These mixtures are manufactured in the factory and are packaged in bags or silos, in the form of a homogeneous powder, ready for mixing on site with water (mixing). These mortars are described in particular in standard NF EN 998-1. In particular, they have the advantage of having very good fire resistance.

The thermal insulation system according to the present invention is fixed directly to the wall or the support to be insulated. The part of the structural element fixed to the wall is positioned either by being pressed against the wall, or positioned a few centimeters (between 1 and 5 cm) from the latter. The wall can be vertical, interior or exterior, wall type, or a horizontal wall, ceiling or floor type. The wall to be coated can be of any type: concrete, bricks, wood, etc. The support on which the insulating system is fixed can be a new support or a support to be renovated. The addition of any other insulator such as insulating panels usually used in ETICS systems such as panels based on EPS or mineral wool for example, is not necessary in the thermal insulation system according to the present invention. The system which is placed on the support to be insulated therefore consists of the mechanical reinforcement element, the insulating mortar layer and the finishing elements.

The three-dimensional structural reinforcement element is formed by cells or empty spaces are filled with a layer of thermally insulating mortar, and on which are placed finishing elements.

The finishing elements are for example a layer of undercoat and a layer of topcoat, to ensure the impermeability and the aesthetics of the coated wall. The thicknesses of the different layers of the finishing elements are identical to those existing in the conventional ITE systems currently used. The undercoat layer has for example a thickness of 3 to 12 mm and the finishing coat layer has a lower thickness, for example of the order of 1 to 6 mm). The finishing elements may also include facing plates, fixed directly to the three-dimensional structural reinforcement element filled with the layer of mortar. In this case, these facing plates replace the layers of undercoating and finishing plaster. The facing plates are fixed to the reinforcement element by gluing with a suitable adhesive mortar and also using a mechanical fixing for optimum reinforcement of the facing, in particular against the actions of the wind.

The insulation system according to the present invention allows in particular a gain in terms of speed of application to the wall to be insulated compared to conventional ITE systems existing on the market. It is no longer necessary to make layouts and to glue or fix insulating plates on the wall. It is also no longer necessary to rectify the flatness of the wall surface, in particular in the case of supports to be renovated, as it is often necessary to do when it is desired to glue or fix the insulating panel. It also makes it possible to limit the quantity of material to be brought to the site itself. Insulation sheets used in conventional ITE systems represent a large footprint, the means of transport necessary to transport them to the site are a significant source of cost.

The reinforcing element used in the insulating system of the present invention is three-dimensional and has a depth of several centimeters. Preferably, the depth of the reinforcing element is at least 40 mm and at most 300 mm. The three-dimensional structural element forms a three-dimensional network of cells or voids filled by the thermally insulating mortar. The depth of the three-dimensional structural element and the thickness of the layer of thermally insulating mortar are linked. In order to obtain a system having the desired mechanical strength, the reinforcing element has a minimum depth corresponding to the thickness of the layer of mortar. The entire voids of the reinforcement element are filled with the mortar layer. The choice of the reinforcing element and in particular its depth is adapted according to the thermally insulating mortar. If the insulation performance of the mortar is very good, the depth of the reinforcing element can be relatively small. On the other hand, if the insulating performance of the insulating mortar is lower, it may be necessary for the thickness of the layer of insulating mortar to be greater and in this case, the depth of the reinforcing element is also greater. In general, the greater the depth of the reinforcing element, the greater the thickness of insulating mortar and the better the performance in terms of thermal insulation of the system according to the present invention, the maximum depth being 300 mm. and advantageously 250 mm.

The reinforcing element can be in different forms, as long as it includes cells or empty spaces which can be filled with the thermally insulating mortar. The structural reinforcing element has a honeycomb structure, a two-dimensional pleated structure or accordion structure, an embossed structure, a structure corresponding to the superposition of at least two two-dimensional grids connected to each other, and / or a structure comprising rigid peaks placed perpendicular to the part fixed to the wall to be insulated. It can also include additional reinforcement means such as peaks perpendicular to the plane formed by the part fixed to the wall to be insulated, and / or one or more two-dimensional meshes.

The cells, or empty spaces located in the reinforcing element can thus have different shapes: square, rectangular, triangular, round, conical, hexagonal, etc. The reinforcing element can be a combination of different shapes between them. Preferably, the reinforcing element comprises a two-dimensional pleated structure, possibly positioned between two two-dimensional meshes, the assembly being secured with peaks placed perpendicular to the part fixed to the wall to be insulated. Such a three-dimensional structure has in particular very good rigidity.

The reinforcing element is made of a non-metallic material to limit thermal conduction through the layer of insulating mortar. The material used is preferably chosen from fiberglass, polypropylene fiber, plastic fiber, nylon fiber, polyamide fiber, natural fiber such as linen or hemp. The reinforcing element may include different types of non-metallic materials. For example, part of the reinforcing member may be made of glass fiber and part, such as stiffer spikes, may be made of plastic. These materials have sufficient rigidity to maintain the reinforcing member in the form of a three-dimensional structure. Advantageously, the reinforcing element is easily compactable, or even rollable, which makes it possible to store and transport it easily to the site of use.

The system according to the present invention can comprise a reinforcing weft, also called a veil. This frame is of the same type as that used in conventional ITE systems. It is a two-dimensional fiber grid such as, for example, that described in patent application US2010 / 0000665. The frame may be integral with the structural reinforcement element and may be considered to be part of this element. It can also be added later and fixed to the reinforcing element once the layer of mortar has been applied, being considered as part of the finishing elements.

The insulating system according to the present invention comprises at least one layer of thermally insulating mortar filling the empty spaces of the reinforcing element. The mortar layer is a light mortar layer, of low density and characterized by good properties in terms of thermal insulation, obtained by mixing different constituents or fillers with water (mixing water) and then by hardening of this. mixed. Several types of compositions can be used in the system according to the present invention.

The mortar layer used in the system according to the present invention is characterized, after drying, by a low thermal conductivity. Advantageously, the thermal conductivity of the mortar is between 25 mW / m. K and 50 mW / mK. Preferably, the insulating mortar has a thermal conductivity less than 35 mW / mK and even more preferably less than 30 mW / mK In terms of density, these values of thermal conductivities correspond to mortars whose apparent density is between 100 and 500 kg / m ³ . These thermal conductivity values also depend on the porosity of the different charges and on the way in which the air is confined in the material. Indeed, at the same density, for loads of different porosity, the thermal conductivity is likely to be different depending on the constituents of the mortar used. The compressive strength of the mortar layer as determined according to standard EN998-1 is not a limiting criterion in the choice of mortar composition since only the mechanical strength of the complete system (structural reinforcement element and thermal insulating mortar ) is to be considered.

The mortar layer is obtained by mixing with water a pulverulent composition comprising at least one hydraulic binder and organic and / or mineral lightening fillers, optionally aggregates, fillers and / or other additives, then by hardening of said mixture.

the mortar layer is a layer of mineral mortar, it has the advantage of not using toxic organic substances and of having, in addition to these thermal insulation performances, good fire resistance. Such a mortar is in particular based on mineral lightening fillers such as expanded perlite, expanded vermiculite, expanded glass beads, hollow glass microspheres, cenospheres, expanded clays, expanded shales, pumice stones, silicates expanded and / or airgel s.

The mortar layer can also comprise synthetic organic lightening fillers such as microspheres based on thermoplastic polymers or copolymers such as expanded or extruded polystyrene, polyethylene, polyethylene terephthalate, polyurethane.

The layer of mortar used in the insulating system according to the present invention can also comprise a mixture of different lightening fillers of mineral type, associated with different lightening fillers of organic type. Mention may, for example, be made of mortar formulations comprising both perlite and aerogels. Patent application EP 2597072 A2 describes in particular formulations of insulating mortars comprising mixtures of aerogels of silica and of expanded polystyrene or of extruded polystyrene. Patent application WO 2014/090790 describes mixtures of lightening charges of the silica aerogel type with pumice stone.

The binder, which ensures cohesion between the various constituents of the mortar, can be a hydraulic binder chosen from Portland cements, mixing cements comprising fly ash, slag, natural or calcined pozzolans, aluminous cements, sulfoaluminous cements, belitic cements and / or hydraulic lime. The binder can also comprise, in addition to the hydraulic binder, other mineral binders based on plaster or based on silicates, air lime, or organic binders, for example based on resins. The binder may also be a phosphate binder resulting from an acid-base reaction generally between a metal salt, such as for example a magnesium salt, a calcium salt, an aluminum salt, or a zinc salt and a derivative or salt of phosphoric acid.

The mortar layer is obtained by hardening a mixture in the form of a paste or foam. The foam can be obtained either by incorporating a pre-formed aqueous foam during the preparation of the mortar, or by adding foaming and / or air entraining agents to the composition which make it possible to form the foam in situ during the preparation of the mortar. A mortar layer in the form of a foam has the advantage of providing additional lightening. An example of a preformed aqueous foam added to the various constituents of the mortar is described in patent application WO 2011/095718. An in-situ foaming process is described for example in application WO 2013/121143. It is advantageous to use a mortar composition in the form of a foam and comprising lightening mineral and / or organic fillers. Mention may for example be made of mortars obtained by mixing silica foam with perlite, as described in patent application WO 2013/150148. These foams are known to be very stable and to have very low thermal conductivities.

The mortar compositions used to form the mortar layer may also include aggregates or sands, affecting the rheology, thickness, hardness, final appearance and permeability of the mortar layer. They are generally formed from silica, limestone and / or silico-limestone sands and have a particle size between 100 μm and 5 mm.

An example of a lightweight insulating mortar composition having good thermal insulation performance comprises a binder consisting of 20 and 60% cement, 20 and 40% lime and 5 to 25% pozzolanic agent, such as metakaolin. , blast furnace slag, sticky ash or silica fumes, mixed with a large quantity (at least 70% by volume) of expanded polystyrene beads.

Another example of a lightweight insulating mortar composition can comprise up to 40% by weight of lightening mineral fillers, a mineral binder, an air-entraining agent and a viscosifying agent, while being free of aggregates of particle size greater than 100 μm .

All the mortar compositions which can be used in the system according to the invention have the characteristic of being sprayable by a spraying machine usually used in the field of facade coating. Wheats can also be applied by machine pouring or by manual application.

The present invention also relates to a method for manufacturing a thermal insulation system for a wall or support which comprises the steps of:

-fixing against said wall, or at a distance of 1 to 5 cm from it, of a three-dimensional non-metallic structural reinforcement element formed of cells or empty spaces,

-projection or pouring of a layer of thermally insulating mortar in said structural reinforcement element so as to fill all of the empty spaces or cells,

-smoothing of the projected layer of mortar once the entire depth of the reinforcing element is filled,

-drying and hardening of the mortar layer, then

- installation of finishing elements.

The reinforcing element is fixed against the wall to be insulated, either by being directly pressed against the wall, or by being kept at a certain distance. The fixing is carried out by fixing means the dimensions of which are such that they do not protrude from the reinforcing element. The reinforcing element can be fixed to the wall by means of fixing rails placed at different heights. These rails can be fitted with hooks for fixing the reinforcing element. Fixing means such as screws, for example with circular head, inserted in dowels placed in the wall to be insulated or staples can also be envisaged.

Advantageously, the reinforcing element is fixed to the wall to be insulated with dowels made up of at least two different parts: a first threaded part and provided with a fixing head, making it possible to fix the part of the element reinforcement which is positioned directly against the wall to be insulated and a second part constituting the body of the dowel, the length of which corresponds to the depth of the structural reinforcement element, and intended to be inserted into the first part of the dowel. The opposite end of the body of the dowel, that is to say the "free" end which does not enter the first part, may be provided with an orifice, possibly tapped, intended to receive a plugging means. . During the projection or pouring step of the insulating mortar layer, the orifice located at the end opposite to that of the wall to be insulated is obscured by a plugging means so as to prevent the orifice from filling. mortar. The plugging means can advantageously be equipped with a flexible part which can be easily located, even after spraying or pouring the layer of mortar and making it possible to add any fixing means for a reinforcing frame, for example. This additional fixing means can be fixed by clipping into the orifice of the second part of the dowel or by screwing in the case of a tapped orifice. Advantageously, the means for fixing the weft can be equipped with spacing means making it possible to leave an empty space between the weft and the dowel allowing in particular that the layer of undercoat covers the entire reinforcement weft before applying the finishing plaster. This type of dowel, the length of which can be variable, is particularly advantageously for fixing the system according to the present invention.

The fixing means used to fix the reinforcement element and in particular an ankle type means such as that described above advantageously make it possible to provide additional reinforcement to the system. The number of fixing means used to fix the system is adapted according to the type of structural element used.

Other fixing means, such as staples, can also be used to directly fix the part of the reinforcing element which is directly in contact with the wall to be insulated. This type of fastening means is particularly suitable when the structural reinforcement element has sufficient rigidity and does not require additional reinforcement. This is particularly the case when the structural reinforcement element is composed of an association of different shapes together, such as accordion shapes coupled to peaks perpendicular to the support.

The reinforcing elements are positioned on the wall to be insulated next to each other. Cover zones between two successive reinforcing elements can be envisaged.

Thus, the insulating system is manufactured in situ directly on the wall to be insulated. The insulating mortar layer is preferably projected or poured into the voids of the reinforcing element, the mortar layer is projected using the mortar spraying machines conventionally used. Depending on the composition and properties of the mortar to be applied, these spraying machines can operate in a continuous or discontinuous mode. The mixing of the dry mortar composition is carried out in the spraying machine. The wet mortar composition at the outlet of the spray lance fills the cells or empty spaces of the structural reinforcement element. The projection can be carried out in several successive passages so as to fill all of the empty spaces of the structural reinforcement element. The various passages can be carried out directly one after the other, without waiting for the drying of the first sprayed layer. The projection techniques used are the usual techniques used by facade makers. The presence of the reinforcing element does not disturb the projection step of the mortar.

The step of drying and hardening the layer of mortar projected or poured into the structural reinforcement element is necessary in order to be able to carry out the step of placing the finishing elements. The duration of this drying and hardening step can vary depending on the projected mortar composition and on the depth of the structural reinforcement element. Conventionally, the recommended duration is one day per centimeter of thickness. This duration can be brought to decrease or to be lengthened according to the climatic conditions.

The implementation of the finishing element placement step depends on the type of finishing systems chosen and the type of structural reinforcement element used. This last step may include a step of applying a layer of undercoat and a topcoat. The undercoat makes it possible in particular to increase the surface hardness and to ensure the protection, in particular waterproofing, of the facade. The finishing coating performs the decoration function (colors, texture, etc.). It may be advantageous to fix a reinforcement frame before or during the application step of an undercoat layer, in particular if the structural reinforcement element does not have a reinforcement frame already integrated. The finishing system chosen may consist in positioning other decorative elements such as for example ceramic tiles, cut stones, natural or artificial, on the structural reinforcement element. These decorative elements can be glued and / or mechanically fixed, either directly on said element, or on a layer of undercoat applied beforehand on said element, possibly comprising a reinforcing weft. The step of fitting the fastening elements may also consist in fixing facing plates on the structural reinforcement element filled with the layer of insulating mortar.

The invention will be better understood in the light of the appended drawings in which:

FIG. 1 is a schematic representation of a first type of structural reinforcement element consisting of a multitude of rigid peaks positioned perpendicular to the part of the element fixed to the wall to be insulated,

FIG. 2 is a schematic representation of a second type of structural reinforcement element having a two-dimensional pleated structure or in the form of an accordion,

FIG. 3 is a schematic representation of a third type of structural reinforcement element consisting of an accordion structure reinforced by rigid peaks perpendicular to the part fixed to the wall to be insulated,

FIG. 4 is a schematic representation of a fourth type of structural reinforcement element consisting of a rigid honeycomb structure, reinforced by rigid peaks placed perpendicular to the part fixed to the wall to be insulated,

FIG. 5 is a schematic representation of a fifth type of structural reinforcement element consisting of two two-dimensional grids joined together by rigid peaks placed perpendicularly to the part fixed to the wall to be insulated, and fixed against the wall by a system of dowels and screws with circular head,

FIGS. 6a to 6d are schematic representations of a fixing means used in the context of the present invention,

FIG. 7a is a schematic representation of the profile of the grid shown in FIG. 3 and FIGS. 7b to 7d are schematic representations of the same grid during folding (FIGS. 7b and 7c) and once compacted (FIG. 7d ).

FIG. 8 gives the curve for variation of the stress as a function of the deformation during the mechanical resistance tests in compression carried out in Example 2 below.

Figure 1 is a schematic representation of a structural reinforcement element (E) comprising a structure (1) on which are positioned also rigid peaks (2) perpendicular to the rigid part (1) positioned against the wall to be insulated. The reinforcing element is fixed to the wall by attachment points (3) in which fixing means such as screws can be easily inserted. The structure and the spikes are for example made of plastic, which gives good rigidity to the reinforcing element. The spaces between the peaks form empty spaces which are then filled with the insulating mortar. The length of the peaks is variable and varies between 40 and 300 mm: it is determined according to the thickness of the layer of insulating mortar desired. The insulating mortar layer is thus easily sprayable into the structural reinforcement element, the rigid peaks making it possible to provide the necessary mechanical resistance.

Figure 2 is a schematic representation on a vertical plane of a structural reinforcement element (E) consisting of a network of son of glass fibers having an accordion shape (4). This structural reinforcement element is obtained in particular by weaving, that is to say by interlacing in the same plane of threads arranged in one direction in the warp direction (warp threads) and of threads arranged in another direction in the direction of the weft (weft threads), in particular perpendicular to the warp threads. These threads are rigid enough that once woven, it is possible to constrain them to obtain a structure in the shape of an accordion. As an example, the resolution of the mesh is 25 mm. The structural reinforcement element is fixed to the wall to be insulated by attachment points (3) located at its ends. Holding elements (5) of the structure in the form of an accordion are arranged over the entire height of the structural reinforcing element (E). This type of structural element has the advantage of being foldable and therefore compactable and easily transportable to the site. Once on site, the operator unfolds the reinforcing element and fixes it on the wall to be insulated, for example by placing screws at the attachment points (3) and also at the level of the retaining elements (5). The mortar layer can thus be projected or poured into the empty spaces or cells of the reinforcing element over a thickness defined by the depth of the reinforcing element.

Figure 3 is a schematic representation on a vertical plane of a structural reinforcement element (E) combining a structure consisting of a network of glass fiber wires having an accordion shape (4), reinforced by rigid peaks (2) perpendicular to the part positioned against the wall to be insulated and also with two-dimensional meshes (6a, 6b) placed in two parallel planes and making it possible to reinforce the structure in the form of an accordion. Thus, one of the two-dimensional meshes (6a) is placed directly against the wall to be insulated and makes it possible to hold the lower parts of the accordion structure together (which are also the parts of the accordion structure placed against the wall). The other mesh (6b) makes it possible to hold the upper parts of the accordion structure together (that is to say the parts which are furthest from the wall to be insulated). The meshes 6a and 6b can be of different dimensions. The wires used to make the two-dimensional meshes can be the same or different from those used to make the accordion structure. The fixing means, not shown in the figure, can be systems of screws / dowels or staples placed at the level of the two-dimensional mesh positioned against the wall to be insulated. The rigid peaks (2) make it possible to hold the entire accordion structure and the two-dimensional meshes together and also to provide additional rigidity to the structural reinforcement element. The peaks can be of variable size and shape. The entire structure therefore reveals cells or empty spaces which will be filled with the insulating mortar. The height of the accordion structure relative to the plane of the support, as well as the height of the rigid peaks (2) make it possible to determine the thickness of the layer of insulating mortar to be sprayed. This type of structural reinforcement allows in particular to project thick layers of mortar.

Figure 4 is a schematic representation on a horizontal plane of a structural reinforcing element (E) consisting of a mesh of three-dimensional glass fiber son in the form of honeycomb, reinforced by rigid peaks (2) perpendicular to the part positioned against the wall to be insulated. The cells are, in this figure, hexagonal in shape, but they can be of different shape, for example square. The depth of the cells corresponds to the thickness of the layer of mortar which is sprayed.

Figure 5 is a schematic representation of a structural reinforcement element placed on a vertical wall to be insulated. The structural reinforcement element shown is made up of two two-dimensional grids or meshes (6a, 6b) of the same dimension joined together by rigid peaks (2) placed perpendicular to the two-dimensional grids. The length of the rigid peaks (2) defines the depth of the sprayable mortar layer. A system for fixing the structural reinforcement element of the dowel / circular head screw type (7) is shown in this figure. This fixing system makes it possible to fix the element on the support and also contributes to its rigidity, since the dowels reinforce the maintenance of the structure provided by the rigid peaks (2).

FIGS. 6a to 6d are a schematic representation, in profile view, of a means for fixing the structural reinforcement element making it possible to fix both said element and also a reinforcement frame forming part of the finishing elements. The structural reinforcement element shown here comprises an accordion-type structure (4) associated with two two-dimensional meshes (6a) and (6b), the mesh (6a) being that positioned against the wall to be insulated. A plug (9), comprising two separate parts (9a) and (9b), is placed in the wall (8) to be insulated. The first part (9a) of the dowel is that which allows the fixing of the structural reinforcement element on the wall to be insulated, by means of a flat and circular dowel head (10). This part of the dowel can be placed at a defined distance from the support to be insulated, which in particular allows a space to be left between the part of the structural element fixed against the wall and the wall itself. This embodiment advantageously makes it possible to correct any flatness defect that may exist on the wall to be insulated (renovation site). The alignment of all the ankles placed at a distance can for example be achieved by a laser system. A second part (9b) of the anchor, the length of which corresponds to the depth of the structural reinforcement element, is inserted by pressing or screwing into the first part (9a) as shown in FIG. 6b. The opposite end of the second part (9b) of the plug is provided with an orifice (11). A plugging means (12) equipped with a flexible and flexible part (13) is placed in the orifice (11) during the step of projecting the layer of mortar into the cells or empty spaces of the reinforcing element. structural. The flexible part advantageously makes it possible to identify the location of the anchor, after projection of the layer of mortar, and in particular during the smoothing step. FIG. 6d gives a schematic representation of the fixing of a reinforcement frame (14) directly in the body of the dowel (9b), in the orifice (11) provided for this purpose. A spacing means (15) is also shown in this figure: it allows sufficient space to be left, for example a few millimeters, between the layer of mortar (or the structural reinforcement element) and the reinforcement frame (14 ) to apply a layer of undercoat. The means for fixing the reinforcement frame (14) is here a screw (16).

It is advantageous to use a structural reinforcement element which is foldable and compactable to facilitate its transport to the site area. Among the various elements described above, those in the form of an accordion present in particular this advantage. Figures 7a to 7d are schematic representations in profile of a structural reinforcement element such as that described in Figure 3 in its unfolded form (Figure 7a) and in its folded forms more or less compact (Figures 7b to 7d). The structural reinforcement element comprises two grids or two-dimensional meshes (6a, 6b), rigid peaks (2) perpendicular to the part positioned against the wall to be insulated and a network of wires forming an accordion structure (4). Such a reinforcing element can be folded back on itself so that the rigid peaks (2) are brought together. The two-dimensional meshes and the accordion structure also fold easily.

All of the structural reinforcement elements described above can be used in combination with an insulating mortar composition. The thickness of the mortar layer is adjusted according to the properties of the insulating mortar and the structure of the reinforcing element.

The examples below illustrate the invention without limiting its scope.

Example 1

Hard body impact tests on a wall coated with an insulating system according to the present invention were carried out.

A structural reinforcement element associating an accordion-shaped structure, rigid peaks with a length of 14 cm and a two-dimensional mesh, identical to that described in FIG. 3, is fixed by a system of screws and dowels at its lower and upper ends on the wall to be insulated A mix is prepared by mixing with water a composition of perlite-based dry mortar and sulfoaluminous cement comprising:

- 70% perlite type 3lcel 42/18,

- 23.7% of sulfoaluminous cement,

- 5% redispersible polymer powder,

- 0.6% cellulose ether,

- 0.6% of air entraining agent, and

- 0.1% setting accelerator.

The apparent density of the dough in the mixing tank is approximately 340 kg / m ³ . The wet mortar composition thus formed is sprayed by a batch machine of the Putzmeister SP11 type, through the reinforcing element, in a single pass. A notched rule dressing was then carried out immediately after spraying the wet mortar. After drying (28 days), the apparent density of the insulating mortar is approximately 180 kg / m ³ . The thermal conductivity is approximately 49 mW / mK The layer of mortar is applied in a single pass over a thickness of 140 mm so as to fill the entire structural reinforcement element.

Once the mortar layer is dry, apply a finishing element which is a mineral undercoat with air lime, conventionally used in current systems of thermal insulation from the outside (Weber, therm XM) : two 3 mm passes of this undercoating were carried out successively with a notched trowel, a finishing weft having strengthened during the first pass. The total thickness of the applied undercoat is between 5 and 6 mm. A silicate facing plaster (Weber.maxilin sil T) was then applied with a trowel on the undercoat layer. After drying of the assembly, a hard body impact test was carried out, by a pendulum drop system, using a steel ball of diameter 50 mm and mass of 500 gr for the test releasing an energy of 3 Joules. The steel ball is attached to the end of a 2 m long rope and is dropped against the wall from a fall height of 0.61 m (angle between the rope and the vertical plane of 46 °). The impact resistance tests are notably described in the document ETAG004, 2013 according to ISO standard 7892. The results obtained have shown that no imprint or crack is visible during the impact test on the wall comprising the insulating system. according to the present invention, which indicates good mechanical resistance of the system.

Example 2: Mechanical tests in simple compression and comparison with rock wool

Mechanical compression tests were carried out with a traction / compression machine. A test tube corresponding to a system according to the present invention was prepared using a reinforcement system such as that described in FIG. 3 (structure in the form of an accordion, rigid peaks with a length of 14 cm and a two-dimensional mesh) in which a waste identical to that described in Example 1 has been projected.

The tests carried out consist in applying a displacement on a test piece in the form of a rectangular prism, placed between two non-deformable horizontal plates, and thus in causing it to be crushed. The displacement and the force applied during the test are simultaneously measured. A constant compression speed of 8 mm / min is applied. One thus expresses the stress in kPa (calculated starting from the applied force measured in Newtons and divided by the surface on which the force is applied) according to the deformation which corresponds to the variation of length AL = L-L0 compared to the initial length of the test piece (AL·L0). The curve obtained is given in FIG. 7. The thickness of the test piece is 105 mm in the case of the system according to the present invention.

By way of comparison, similar tests have been carried out by replacing the system according to the present invention with rock wool of a thickness of 80 mm, usually used in exterior insulation systems. Two tests were carried out, the first using a rock wool of density 130 kg / m ³ (sample 1) and the second a rock wool of density 125 kg / m ³ (sample 2). The comparison between the different samples tested shows that the system according to the present invention has a mechanical behavior quite comparable to that obtained with rock wool.

Claims (20)

1. Thermal insulation system from the outside of a wall which includes - at least one non-metallic three-dimensional structural reinforcement element (E) formed of cells or empty spaces and of a part fixed to the wall (8) to be insulated, - at least one layer of thermally insulating mortar filling all of the cells or empty spaces of the reinforcing element and - at least finishing elements. 2. System according to claim 1 characterized in that the structural reinforcing element (E) has a depth of at least 40 mm and at most 300 mm. 3. System according to one of the preceding claims, characterized in that the structural reinforcing element (E) has a honeycomb structure, a two-dimensional pleated structure or accordion structure (4), an embossed structure, a structure corresponding to the superposition of at least two two-dimensional grids connected to each other, and / or a structure comprising rigid peaks (2) placed perpendicular to the part fixed to the wall to be insulated. 4. System according to the preceding claim characterized in that the structure of the reinforcing element (E) comprises additional reinforcing means such as peaks (2) perpendicular to the plane formed by the part fixed on the wall (8) to isolate, and / or one or more two-dimensional meshes (6a, 6b). 5. System according to the preceding claim characterized in that the reinforcing element (E) comprises a two-dimensional pleated structure, possibly positioned between two two-dimensional meshes (6a, 6b), the assembly being secured with rigid peaks (2) placed perpendicular to the part fixed to the wall (8) to be insulated. 6. System according to one of the preceding claims, characterized in that the structural reinforcement element is made of one or more materials chosen from glass fiber, polypropylene fiber, plastic fiber, nylon fiber, polyamide fiber, natural fiber such as linen or hemp. 7. System according to one of the preceding claims, characterized in that the layer of mortar is a layer of lightened mortar, the thermal conductivity of which is between 25 mW / mK and 50 mW / mK, preferably between 25 mW and 35 mW / mK and even more preferably between 25 mW / mK and 30 mW / mK 8. System according to one of the preceding claims, characterized in that the mortar layer is obtained by mixing with water a pulverulent composition comprising at least one hydraulic binder with organic and / or mineral lightening fillers, optionally in presence of aggregates, fillers and / or other additives and then by curing said mixture. 9. System according to claim 8 characterized in that the mineral lightening fillers are chosen from expanded perlite, expanded vermiculite, expanded glass beads, hollow glass microspheres, cenospheres, expanded clays, expanded shales, pumice stones, expanded silicates, and / or aerogels. 10. System according to claim 9 characterized in that the synthetic lightening fillers are chosen from microspheres based on thermoplastic polymers or copolymers such as expanded or extruded polystyrene, polyethylene, polyethylene terephthalate, polyurethane. 11. System according to one of claims 9 to 10 characterized in that the binder is chosen from hydraulic binders such as Portland cements, mixing cements comprising fly ash, slag, natural or calcined pozzolans, cements aluminous, sulfoaluminous cements, belitic cements and / or hydraulic lime, or among organic binders, or among phosphate type binders resulting from an acid-base reaction between a metal salt and a derivative or a salt of the phosphoric acid and / or among mineral binders based on plaster or based on silicates, hydraulic or aerial lime. 12. System according to one of the preceding claims, characterized in that the mortar layer is obtained after hardening of a mixture in the form of paste or foam. 13. System according to the preceding claim, characterized in that the foam is obtained by incorporating a pre-formed aqueous foam during the preparation of the mortar, or by adding foaming agents and / or air entrainers to the composition which allow to form the foam in situ during the preparation of the mortar. 14. Method for manufacturing a thermal insulating system from the outside of a support or wall, characterized in that it comprises the steps of: -fixing against said wall (8) or at a distance of 1 to 5 cm from the latter of a three-dimensional non-metallic structural reinforcement element (E) formed of cells or empty spaces, -projection or pouring of a layer of thermally insulating mortar in said structural reinforcement element (E) so as to fill all of the empty spaces or cells, -smoothing the projected layer of mortar once the entire depth of the reinforcing element (E) is filled, -drying and hardening of the mortar layer, then - installation of finishing elements. 15. Method according to claim 14 characterized in that the fixing is carried out by fixing means (7) whose dimensions are such that they do not protrude from the reinforcing element. 16. Method according to one of claims 14 or 15 characterized in that the fixing is carried out by fixing means (7) whose dimensions are such that they allow to maintain a distance of 1 to 5 cm between the element structural and the wall. 17. Method according to one of claims 14 to 16 characterized in that the projection of the mortar layer is carried out by several successive passages so as to fill all of the cells or empty spaces of the reinforcing element. 18. Method according to one of claims 14 to 17 characterized in that the step of placing the finishing elements comprises a step of applying a layer of undercoat and a topcoat. 19. The method of claim 18 characterized in that it further comprises a step of fixing a reinforcing frame before or during the application of the undercoat layer. 20. Method according to one of claims 14 to 19 characterized in that 5 decorative elements are glued or mechanically fixed on the hardened layer of mortar, optionally coated with an undercoat and a reinforcing weft.