WO2018115766A1

WO2018115766A1 - System for thermal insulation from the outside, made up of a highly insulating pneumatic mortar, and method for manufacturing the system

Info

Publication number: WO2018115766A1
Application number: PCT/FR2017/053771
Authority: WO
Inventors: Michaël PERRAT-DIT-GENTON; Daniel Comoy; Antoine GIRET; Xavier AUFFRET
Original assignee: Saint-Gobain Weber
Priority date: 2016-12-22
Filing date: 2017-12-21
Publication date: 2018-06-28
Also published as: FR3061221A1; FR3061221B1; EP3559367A1

Abstract

The present invention relates to a system for thermal insulation from the outside of a wall, which comprises: at least one non-metal three-dimensional structural reinforcement element made up of empty spaces or cavities and a portion attached to the wall to be insulated; at least one layer of thermally insulating mortar filling all the empty spaces or cavities of the reinforcement element; and at least finishing elements.

Description

OUTDOOR THERMAL INSULATION SYSTEM CONSISTING OF HIGHLY INSULATING PROJECTED MORTAR AND METHOD OF MANUFACTURING THE SYSTEM

The present invention relates to an external thermal insulation system (ITE) implementing a highly insulating mortar filling a mechanical reinforcement grid.

External thermal insulation is a solution currently widely used in the field of construction both in renovation and new construction. There are several types of thermal insulation from the outside. The most widespread systems on the market today use rigid insulating panels bonded to the substrate in accordance with a regulated layout plan. These panels are based on expanded polystyrene, optionally with added graphite, based on phenolic foam or polyurethane, based on mineral wool such as glass wool or rock wool, or based on cork or any other known material for its insulation properties. On these insulating panels, it is necessary to apply a base coating (or reinforcing plaster) reinforced with a grid or lattice on which a finishing plaster is then applied to provide the necessary protection and aesthetic appearance. These systems are complex and are known as the 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 spread out at 12 mW / m. K for vacuum insulation panels at 130 mW / m. K. for some OSB (Oriented Strand Board) chipboard. 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 on the support have the advantage of being mechanically strong enough to support the weight of undercoated as well as finishing coatings or paint. However, the addition of heavy facings such as ceramic tiles, carved stones or glass panels is strictly regulated in terms of the limit weight per square meter and in terms of height of building structures.

More recently, other types of external insulation systems based on projected mortars have developed. These mortars are based on lightening loads such as expanded polystyrene beads, pearlite beads, expanded glass beads or aerogels. They are projected on 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 phase of rectification of the flatness of the support, especially the old supports in case of renovation, and also the bonding phase of the insulating panel. However, the thermal performance of the projected mortars severely depends on their density. In order to lower the value of the thermal conductivity of a sprayed mortar, it is necessary to lower its density and consequently to use large amounts of lightening fillers, and also foaming agents and / or air entraining agents. The drop in density results in a drastic reduction in the mechanical performance of these products, and therefore a lower bearing capacity vis-à-vis the finishing facings.

We therefore seek a solution that combines both the performance in terms of thermal insulation and mechanical strength. It is in this context that the present invention provides a thermal insulation system 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 of a wall which comprises:

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

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

- at least finishing elements. Thus, the reinforcing element makes it possible to obtain the mechanical strength and the mortar layer makes it possible to obtain the expected thermal insulation performance. It thus becomes possible, thanks to the structural reinforcement element, to use mortars, in particular inorganic mortars, 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, extracted from natural materials, silico-limestone fillers and inert pigments, additives and additives. 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 in particular described in standard NF EN 998-1. In particular, they have the advantage of having a very good fire resistance.

The thermal insulation system according to the present invention is fixed directly on the wall or the support to be insulated. The part of the structural element fixed on the wall is positioned either by being pressed against the wall or positioned a few centimeters (between 1 and 5 cm) thereof. The wall may be vertical, interior or exterior wall type, or a horizontal wall type ceiling or floor. The wall to be coated can be of any type: concrete, bricks, wood, etc. The support on which the insulating system is fixed may be a new support or a support to be renovated. The addition of any other insulation such as insulating panels commonly used in ETICS systems such as EPS-based panels or mineral wool for example, is required 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 reinforcing element, the insulating mortar layer and the finishing elements.

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

The finishing elements are, for example, an undercoat layer and a topcoat layer, to ensure the impermeability and aesthetics of the coated wall. The thicknesses of the different layers of the elements of finishes are identical to those existing in conventional ITE systems currently used. The undercoat layer has for example a thickness of 3 to 12 mm and the topcoat layer has a lower thickness, for example of the order of 1 to 6 mm). The finishing elements may also include facing plates, attached directly to the three-dimensional structural reinforcing element filled with the mortar layer. In this case, these facing plates replace the layers of under-coating and finishing plaster. The facing plates are fixed to the reinforcing element by bonding with a suitable adhesive mortar and also with the aid of a mechanical fastening 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 on the wall to be isolated compared to conventional ITE systems existing on the market. It is no longer necessary to plan layouts and stick or fix on the wall insulating plates. It is also no longer necessary to rectify the flatness of the surface of the wall, especially in the case of the substrates to be renovated as it is often necessary to do when it is desired to glue or fix the insulating panel. It also limits the amount of material to be brought to the site itself. The insulation boards used in conventional ITE systems represent a significant amount of space, the means of transport required to transport them to the site are a source of significant 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 thermally insulating mortar layer are related. In order to obtain a system having the desired mechanical strength, the reinforcing element has a depth minimum corresponding to the thickness of the mortar layer. All of the voids of the reinforcing element are filled by the mortar layer. The choice of the reinforcing element and in particular its depth is adapted according to the thermally insulating mortar. If the insulating performance of the mortar is very good, the depth of the reinforcing element can be relatively low. On the other hand, if the insulating performance of the insulating mortar is lower, it may be necessary for the thickness of the insulating mortar layer 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 the insulating mortar and the better the thermal insulation performance of the system according to the present invention, the maximum depth being 300 mm. and advantageously 250 mm.

The reinforcing member may be in a variety of forms from the moment it includes cavities or voids that can be filled by the thermally insulating mortar. The structural reinforcement element has a honeycomb structure, a pleated two-dimensional structure or an 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 portion fixed on the wall to be insulated. It may also comprise additional reinforcing means such as peaks perpendicular to the plane formed by the part fixed on the wall to be insulated, and / or one or more two-dimensional meshes.

The cells or voids in the reinforcing element can thus have different shapes: square, rectangular, triangular, round, conical, hexagonal, etc. The reinforcing member may be an association of different shapes with each other. Preferably, the reinforcing element comprises a folded two-dimensional structure, possibly positioned between two two-dimensional meshes, the assembly being secured to placed peaks. perpendicular to the part fixed on the wall to be insulated. Such a three-dimensional structure has in particular a very good rigidity.

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

The system according to the present invention may comprise a reinforcement weft, also called a sail. This frame is of the same type as that used in conventional ITE systems. This is a two-dimensional fiber grid such as, for example, that described in patent application US2010 / 0000665. The weft may be integral with the structural reinforcement element and may be considered as part of this element. It can also be added later and fixed on the reinforcing element once the mortar layer has been applied, then 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 lightened 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 hardening it. mixed. Several types of compositions are usable 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 of less than 35 mW / m. K and even more preferably less than 30 mW / mK. In terms of density, these thermal conductivity values 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 how the air is confined in the material. Indeed, at the same density, for charges 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 EN998-1 is not a limiting criterion in the choice of the 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 leaching fillers, optionally aggregates, fillers and / or other additives, then by hardening said mixture.

If the mortar layer is a mineral mortar layer, it has the advantage of not using toxic organic substances and having, in addition to these thermal insulation performance, 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 aerogels.

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

The mortar layer used in the insulating system according to the present invention may also comprise a mixture of different mineral-type lightening fillers associated with various organic-type lightening fillers. For example, there may be mentioned mortar formulations comprising both perlite and aerogels. The patent application EP 2597072 A2 describes in particular insulating mortar formulations comprising mixtures of aerogels of silica and expanded polystyrene or extruded polystyrene. The patent application WO 2014/090790 describes blends of leaching charges silica airgel type with pumice stone.

The binder, which ensures cohesion between the various constituents of the mortar may be a hydraulic binder selected from Portland cements, mixing cements comprising fly ash, slags, natural or calcined pozzolans, aluminous cements, sulfoaluminous cements, belitic cements and / or hydraulic lime. The binder may also comprise, in addition to the hydraulic binder, other mineral binders based on plaster or on the basis of silicates, aerial 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 a salt of phosphoric acid.

The mortar layer is obtained by curing a mixture in the form of 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 in the composition foaming agents and / or air entraining agents which make it possible to form the foam in situ during preparation of the mortar. A layer of mortar in the form of a foam has the advantage of providing additional relief. An example of a preformed aqueous foam added to the various constituents of the mortar is described in the patent application WO 201 1/095718. A In-situ foaming process is described for example in the application WO 2013/121 143. It is advantageous to use a mortar composition in the form of foam and comprising mineral and / or organic lightening fillers. Mention may be made, for example, 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, varying in the rheology, thickness, hardness, final appearance and permeability of the mortar layer. They are generally formed of siliceous, calcareous and / or silico-calcareous sands and have a particle size of between 100 μητι and 5 mm.

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

Another example of a lightened insulating mortar composition may comprise up to 40% by weight of lightening mineral filler, a mineral binder, an air entraining agent and a viscosing agent, while being free of aggregates having a particle size greater than 100 m. .

The set of mortar compositions that can be used in the system according to the invention has the characteristic of being projectable by a projection machine usually used in the field of facade cladding. They can also be applied by machine casting or by manual application. The present invention also relates to a method of manufacturing a thermal insulation system of a wall or support which comprises the steps of: attaching to said wall, or at a distance of 1 to 5 cm from it, a three-dimensional non-metallic structural reinforcement element formed of cavities or voids,

-projection or casting of a thermally insulating mortar layer in said structural reinforcing element so as to fill all the empty spaces or cavities,

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

drying and hardening of the mortar layer, then

- setting up finishing elements.

The reinforcing element is fixed against the wall to be insulated, either by being directly plated on the wall, or by being held at a distance. Fixing is carried out by fixing means whose dimensions are such that they do not exceed the reinforcing element. The reinforcing element can be fixed on the wall by means of fixing rails placed at different heights. These rails can be equipped with hooks for fixing the reinforcing element. Fastening means such as screws, for example with a circular head, inserted in pins placed in the wall to be insulated or staples can also be envisaged.

Advantageously, the reinforcing element is fixed on the wall to be insulated with pins consisting of at least two different parts: a first threaded portion and provided with a fixing head, for fixing the part of the element reinforcement which is positioned directly against the wall to be insulated and a second portion constituting the body of the dowel whose length 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 peg, that is to say the "free" end that does not penetrate into the first part may be provided with a hole, possibly tapped, for receiving a closure means. During the step of spraying or pouring the insulating mortar layer, the orifice located at the end opposite to that of the wall to be insulated is concealed by a closure means so as to prevent the orifice from becoming blocked. fill with mortar. The closure means may advantageously be equipped with a flexible part which can be easily identified, even after the mortar layer has been sprayed or poured, and it is possible to add a possible fastening means for a reinforcement frame, for example. This additional fixing means can be fixed by clipping in the orifice of the second part of the dowel or by screwing in the case of a tapped hole. Advantageously, the weft attachment means may be equipped with a spacer means allowing a gap between the weft and the peg to be left, in particular allowing the undercoat layer to cover the entire reinforcing weft. before laying the finishing plaster. This type of peg whose length can be variable is particularly advantageously for fixing the system according to the present invention.

The fastening means used to fasten the reinforcing 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 fastening means used to fasten the system is adapted according to the type of structural element implemented.

Other fastening means, such as staples may also allow to directly attach the portion 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 a combination 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. Areas of overlap between two successive reinforcing elements are conceivable.

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

The step of drying and hardening of the mortar layer cast or cast in 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 curing step may vary depending on the projected mortar composition and the depth of the structural reinforcement element. Classically, the recommended duration is one day per centimeter of thickness. This duration may be reduced or lengthened depending on the climatic conditions.

The implementation of the step of placing the finishing elements depends on the type of finishing systems chosen and the type of structural reinforcement element used. This last step may comprise a step of applying a layer of under-coating and a finishing coating. The sub-coating makes it possible in particular to increase the surface hardness and to ensure the protection, especially the waterproofing, of the facade. The finishing coating provides the decoration function (colors, texture ...). It may be advantageous to fix a reinforcement weft before or during the step of applying a sub-plaster layer, especially if the structural reinforcement element does not have an already integrated reinforcing ply. The finishing system chosen may consist of positioning other elements decorative 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 sub-plaster layer previously applied to said element, possibly comprising a reinforcement weft. The step of placing the fastening elements may also consist of 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 portion of the element attached to the wall to be isolated,

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 portion fixed on the wall to be isolated,

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 perpendicularly to the part fixed on the wall to be insulated,

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

FIGS. 6a to 6d are diagrammatic representations of a fastening means used in the context of the present invention, FIG. 7a is a schematic representation of the profile of the grid represented 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. ).

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

FIG. 1 is a schematic representation of a structural reinforcing element (E) comprising a structure (1) on which are positioned additional reinforcing means such as equally 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 hooking points (3) in which fastening means such as screws can be easily inserted. The structure and the peaks are for example plastic, which gives a good rigidity to the reinforcing element. The spaces between the peaks form empty spaces which are then filled by 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 desired insulating mortar layer. The insulating mortar layer is thus easily sprayable into the structural reinforcement element, the rigid peaks making it possible to provide the necessary mechanical strength.

FIG. 2 is a schematic representation on a vertical plane of a structural reinforcing element (E) consisting of a network of glass fiber strands having an accordion shape (4). This structural reinforcing element is obtained in particular by weaving, that is to say by crossing in the same plane of threads arranged in a direction in the direction of the warp (warp threads) and son arranged in another direction in the direction of the weft (weft threads), especially 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 form of an accordion. For example, the resolution of the mesh is 25 mm. The structural reinforcement element is fixed on the wall to be insulated by hooked points (3) at its ends. Holding elements (5) of the structure in accordion form are arranged over the entire height of the structural reinforcement element (E). This type of structural element has the advantage of being foldable and therefore compactable and easily transportable to the site. Once on the site, the operator unfolds the reinforcing element and fixed on the wall to be insulated, for example by placing screws to the hook points (3) and also at the level of the holding elements (5). The mortar layer can then be projected or cast in the voids or cavities of the reinforcing element to a thickness defined by the depth of the reinforcing element.

FIG. 3 is a diagrammatic representation on a vertical plane of a structural reinforcing element (E) associating a structure consisting of a network of glass fiber strands having an accordion shape (4), reinforced by means of additional reinforcement such as rigid peaks (2) perpendicular to the portion positioned against the wall to be insulated and also with two-dimensional meshes (6a, 6b) placed in two parallel planes and for reinforcing the accordion-shaped structure. Thus, one of the two-dimensional meshes (6a) is placed directly against the wall to be insulated and keeps the lower parts of the accordion structure (which are also the parts of the concertina structure placed against the wall) integral with one another. The other mesh (6b) makes it possible to keep the upper parts of the accordion structure (that is to say the parts that are farthest from the wall to be insulated) integral. The meshes 6a and 6b may be of different size. The yarns used to make the two-dimensional meshes may be identical or different from those used to make the accordion structure. The fastening means, not shown in the figure, may be screw / dowel systems or staples placed at the two-dimensional mesh positioned against the wall to be insulated. The rigid peaks (2), distinct from the fastening means of the reinforcing element, make it possible to maintain the entire accordion structure and the two-dimensional meshes together and also to provide additional rigidity to the element of the reinforcement element. structural reinforcement. Peaks can be of varying size and shape. The entire structure therefore reveals cavities or voids which will be filled by 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 element allows in particular to project thick mortar layers.

FIG. 4 is a diagrammatic representation on a horizontal plane of a structural reinforcement element (E) consisting of a grid of honeycomb-shaped three-dimensional glass fiber strands, reinforced by rigid perpendicular peaks (2). at the part positioned against the wall to be insulated. The cells are, in this figure, of hexagonal shape, but they can be of different shape, for example square. The depth of the cells corresponds to the thickness of the mortar layer that is projected.

Figure 5 is a schematic representation of a structural reinforcement element placed on a vertical wall to be insulated. The structural reinforcement element shown consists of two grids or two-dimensional meshes (6a, 6b) of the same dimension secured to each other 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 fastening system of the structural anchoring element of the plug / screw type with circular head (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 ensured by the rigid peaks (2).

FIGS. 6a to 6d are a diagrammatic representation, in profile view, of a fixing means of the structural reinforcement element making it possible to fix both said element and also a reinforcement weft 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. An ankle (9), comprising two distinct parts (9a) and (9b), is placed in the wall (8) at isolate. The first part (9a) of the ankle is that which allows the fixation of the structural reinforcement element on the wall to be isolated, via a flat and circular dowel head (10). This part of the ankle may be placed at a defined distance from the support to be insulated, which allows in particular to leave a space between the part of the structural element fixed against the wall and the wall itself. This embodiment advantageously makes it possible to correct any lack of flatness that may exist on the wall to be insulated (renovation project). The alignment of all the pins placed at a distance can for example be achieved by a laser system. A second portion (9b) of the dowel whose length corresponds to the depth of the structural reinforcement element is inserted by depression or screwing into the first portion (9a) as shown in Figure 6b. The opposite end of the second portion (9b) of the ankle is provided with an orifice (1 1). A closure means (12) equipped with a flexible and flexible portion (13) is placed in the orifice (1 1) during the step of projecting the mortar layer into the cells or voids of the element of structural reinforcement. The flexible part advantageously makes it possible to locate the location of the ankle, after projection of the mortar layer, and in particular during the smoothing step. Figure 6d gives a schematic representation of the attachment of a reinforcing frame (14) directly in the body of the pin (9b), in the orifice (1 1) provided for this purpose. A spacing means (15) is also shown in this figure: it allows a sufficient space, for example a few millimeters, between the mortar layer (or the structural reinforcement element) and the reinforcement weft (1). ) to apply a layer of undercoat. The fastening means of the reinforcing frame (14) is here a screw (16).

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

The set of 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 clean 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 have been carried out.

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

- 70% of perlite of Silcel type 42/18,

- 23.7% of sulphoaluminous cement,

5% of redispersible polymer powder,

0.6% cellulose ether,

0.6% of air entraining agent, and

- 0, 1% of setting accelerator agent.

The apparent density of the pulp in the mixing tank is about 340 kg / m ³ . The wet mortar composition thus formed is projected by a discontinuous machine of Putzmeister SP1 type 1, through reinforcement element in one pass. Training with the ruler was then performed immediately after the wet mortar was sprayed. After drying (28 days), the apparent density of the insulating mortar is about 180 kg / m ³ . The thermal conductivity is about 49 mW / m. K. The mortar layer 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 that is an underlay mineral aerial lime, conventionally used in the current systems of thermal insulation from the outside (Weber.therm XM): two 3 mm passes of this sub-plaster were made successively to the notched trowel, a finishing frame having shifted during the first pass. The total thickness of the applied sub-plaster is between 5 and 6 mm. A silicate-based facing plaster (Weber maxilin sil T) was then applied to the trowel over the undercoat layer. After drying the assembly, a hard body impact test was carried out by a pendulum drop system, using a steel ball with a diameter of 50 mm and a mass of 500 gr for the test releasing an energy of 3 Joules. The steel ball is attached to the end of a rope 2 m long and is dropped against the wall from a drop height of 0.61 m (angle between the rope and the vertical plane of 46 °). The impact resistance tests are described in particular in document ETAG004, 2013 according to the ISO 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 reflects a good mechanical strength of the system.

Example 2: Mechanical Tests in Simple Compression and Comparison with Rockwool

Mechanical compression tests were performed with a traction / compression machine. A test piece corresponding to a system according to the present invention was prepared using a reinforcement system such as that described in FIG. 3 (accordion-shaped structure, peaks 14 cm long rigid and a two-dimensional mesh) in which a mix identical to that described in Example 1 was projected.

The tests consist in applying a displacement on a specimen in the form of a rectangular prism, placed between two horizontal plates indeformable, and thus to cause crushing thereof. The displacement and the force applied during the test are simultaneously measured. A constant compression rate of 8 mm / min is applied. Thus the stress is expressed in kPa (calculated from the applied force measured in Newtons and divided by the area on which the force is applied) as a function of the strain corresponding to the variation of length ΔΙ_ = Ι_-Ι_0 compared to the initial length of the test piece (AL / LO). 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 were carried out by replacing the system according to the present invention with rock wool with a thickness of 80 mm, usually used in insulation systems from the outside. Two tests were carried out, the first using a rock wool of density 1 30 kg / m ³ (sample 1) and the second a rock wool with a density of 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

1. Thermal insulation system from the outside of a wall which comprises - at least one non-metallic three-dimensional structural reinforcement element (E) formed of cells or voids and a part fixed on the wall (8) to isolate,

- 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 structure pleated 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 portion fixed on 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 portion 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 folded two-dimensional structure, possibly positioned between two two-dimensional meshes (6a, 6b), the assembly being secured to rigid peaks (2) placed perpendicular to the part fixed on the wall (8) to be insulated.

6. System according to one of the preceding claims characterized in that the structural reinforcement element is made in one or more materials selected from fiberglass, polypropylene fiber, plastic fiber, nylon fiber, polyamide fiber, natural fiber such as flax or hemp.

7. System according to one of the preceding claims characterized in that the mortar layer is a lightened mortar layer whose thermal conductivity is between 25mW / m. K and 50 mW / m. K, preferably between 25 mW and 35 mW / m. K and even more preferably between 25 mW / m. K and 30 mW / m. K.

8. System according to one of the preceding claims characterized in that the mortar layer is obtained by mixing with water of a powder composition comprising at least one hydraulic binder with organic and / or mineral leaching loads, optionally in presence of aggregates, fillers and / or other additives and then hardening 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 selected from microspheres based on thermoplastic polymers or copolymers such as expanded or extruded polystyrene, polyethylene, polyethylene terephthalate, polyurethane.

1 1. System according to one of Claims 9 to 10, characterized in that the binder is chosen from hydraulic binders such as Portland cements, mix cements comprising fly ash, slags, natural or calcined pozzolans, aluminous cements, sulphoaluminous cements, belitic cements and / or hydraulic lime, or among organic binders, or among phosphate binders resulting from an acid-base reaction between a metal salt and a derivative or a salt of phosphoric acid and / or among the mineral binders to base of plaster or based on silicates, hydraulic or aerial lime.

2. System according to one of the preceding claims characterized in that the mortar layer is obtained after curing a mixture in the form of paste or foam.

3. 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 to the composition foaming agents and / or air entrainers which allow the foam to be formed in-situ during the preparation of the mortar.

14. A method of manufacturing a thermal insulation system from the outside of a support or wall characterized in that it comprises the steps of: -fixation against said wall (8) or at a distance of 1 to 5 cm of the latter of a three-dimensional non-metallic structural reinforcement element (E) formed of cavities or voids,

-projection or casting of a layer of thermally insulating mortar in said structural reinforcing element (E) so as to fill all the empty spaces or cavities,

smoothing the projected mortar layer once the entire depth of the reinforcing element (E) is filled,

drying and hardening of the mortar layer, then

- setting up finishing elements.

15. The method of claim 14 characterized in that the fixing is performed by fixing means (7) whose dimensions are such that they do not exceed the reinforcing element.

16. Method according to one of claims 14 or 15 characterized in that the fixing is performed 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 wall.

17. Method according to one of claims 14 to 16 characterized in that the projection of the mortar layer is performed by several successive passages so as to fill all the cells or voids 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 finishing coating.

19. The method of claim 18 characterized in that it further comprises a step of fixing a reinforcement weft before or during the application of the undercoat layer.

20. Method according to one of claims 14 to 19 characterized in that decorative elements are bonded or mechanically fixed on the hardened mortar layer, optionally coated with a sub-coating and a reinforcing frame.