WO2024146890A1

WO2024146890A1 - Insulating wall arrangement

Info

Publication number: WO2024146890A1
Application number: PCT/EP2024/050055
Authority: WO
Inventors: Julie GODEFROID; David LUIS
Original assignee: Saint-Gobain Isover
Priority date: 2023-01-04
Filing date: 2024-01-03
Publication date: 2024-07-11

Abstract

The invention relates to a method for obtaining a wall arrangement (1) comprising two walls (3, 5) consisting of blocks, concrete or mortar and facing each other so as to form at least one cavity (7) filled with an insulating material (9) comprising flakes of mineral or plant wool, said method comprising blowing said flakes into said cavity (7) by means of a blowing nozzle (8), said walls (3, 5) being arranged, during blowing, so as to extend along a vertical axis (Z) from their lower end, of vertical coordinate 0, up to their upper end, of vertical coordinate H, the cavity (7) opening out at said upper end and being accessible from the top, and said flakes being blown downwards, said method comprising a first blowing step in which the blowing nozzle (8) is positioned at a lower location of the cavity having a vertical coordinate of between 0 and H/2, then a final blowing step in which the blowing nozzle (8) is positioned at an upper location of the cavity having a vertical coordinate of between 2H/3 and H.

Description

Insulating wall

The present invention relates to the field of construction. It concerns more precisely an insulating wall as well as its production process.

It is known to fill cavities in construction elements, such as walls or parts of walls, using insulating materials, such as mineral wool or inorganic foams (for example cement foams). or organic (for example polyurethane foams).

These different solutions are, however, not without their drawbacks. The filling of the cavities with the insulating material is not always homogeneous, leading to the creation of thermal bridges and therefore to a degradation of thermal insulation performance. These defects in homogeneity can occur over time or during the transport of construction elements to the site, when they are prefabricated elements. For example, mineral wool-based materials can tend to settle, and we sometimes observe a shrinkage of inorganic foams. Organic foams sometimes exhibit poorly controlled expansion during installation. Some known solutions also do not lend themselves well to automation.

The invention aims to obviate these drawbacks by proposing a wall which has a lower overall thermal conductivity, thanks to better homogeneity of the filling of the cavity.

To this end, the subject of the invention is a method for obtaining a wall comprising two walls made of concrete blocks, concrete or mortar and facing each other so as to provide at least one cavity filled with an insulating material comprising flakes of mineral or vegetable wool, said method comprising blowing said flakes into said cavity by means of a blowing nozzle, said walls being arranged during blowing so as to extend along a vertical axis from their lower end, of coordinate vertical 0, to their upper end, of vertical coordinate H, the cavity opening out at said upper end and accessible from above, and said flakes being blown downwards, said method comprising a first blowing step in which the blowing nozzle is positioned at a bottom location of the cavity having a vertical coordinate between 0 and H/2, then a final blowing step in which the blowing nozzle is positioned at a top location of the cavity having a vertical coordinate between 2H/3 and H.

The invention also relates to a wall comprising two walls made of concrete blocks, concrete or mortar and facing each other so as to provide a cavity filled with an insulating material comprising flakes of mineral or vegetable wool capable of being obtained by this process.

The process according to the invention makes it possible, thanks to a particular filling method, to obtain excellent homogeneity of the insulating material and consequently a wall with low thermal conductivity.

The different preferred characteristics presented in the present description are applicable to both the process and the construction element.

The wall can be a load-bearing wall or a shear wall. The wall is preferably a wall erected directly on the construction site of the building for which the wall is intended. The process then includes a preliminary step of erecting said wall on the construction site.

The walls of the wall are made of concrete blocks, concrete or mortar. Concrete blocks include bricks, blocks, stones or rubble. The walls are then formed by assembling a plurality of concrete blocks, for example using masonry mortar. The two walls can be made of the same material, or even different materials. The walls are therefore not made of a breathable material.

The walls are generally flat and parallel to each other, but other geometries are of course possible, in particular when they are obtained by additive manufacturing, as described in more detail later in the text.

The walls can provide one or more cavities. In the latter case, it is preferable to fill all the cavities.

The lateral dimensions of the wall are preferably between 0.5 and 3 m, in particular between 0.75 and 2.5 m, or even between 1 and 2 m. As examples, the wall can have, along a horizontal axis a length L of 2 m and along a vertical axis a height H of 2.5 m. The thickness of the cavity (i.e. the distance separating the walls – wall thickness excluded) is preferably between 5 and 50 cm, in particular between 10 and 40 cm, or even between 15 and 30 cm.

The insulating material preferably comprises at least 90%, in particular at least 95%, or even at least 99% by weight, of mineral or vegetable wool flakes. The insulating material can consist of flakes of mineral or vegetable wool.

Mineral wool is preferably chosen from glass wool, slag wool, rock wool and mixtures of two or more of these wools. The mineral wool fibers preferably have a chemical composition comprising 30 to 75% by weight of SiO ₂ , 5 to 40% by weight of CaO+MgO, 0-20% by weight of Na ₂ O+K ₂ O, 0- 30% by weight of Al ₂ O ₃ and 0-15% by weight of Fe ₂ O ₃ .

The use of glass wool generally allows better thermal insulation performance to be achieved, in particular thanks to a lower density.

Glass wool is generally formed by electrical or flame fusion of a mixture of powdery raw materials and cullet (recycled glass), then fiberizing, in particular by internal centrifugation using a fiberizing plate. The glass wool fibers preferably have a chemical composition comprising 50-75% SiO ₂ , 10 to 25% Na ₂ O+K ₂ O, 5 to 20% CaO+MgO, 0-8%, notably 0-3 % Al ₂ O ₃ and 0 to 10%, in particular 2 to 8% B ₂ O ₃ (the percentages being by weight).

Rock and slag wool are generally formed by cupola furnace fusion of raw materials in the form of blocks and/or briquettes, or by electric fusion or by submerged burners of powdery materials, then fiberization by external centrifugation using of a plurality of rotors. Rock wool fibers preferably have a chemical composition comprising 30-50% SiO ₂ , 10-26% Al ₂ O ₃ , 15-40% CaO+MgO, 0-5% Na ₂ O+K ₂ O and 3 -15% Fe ₂ O ₃ . The slag wool fibers preferably have a chemical composition comprising 30-45% SiO ₂ , 5-18% Al ₂ O ₃ , 30-60% CaO+MgO and 0-3% Na ₂ O+K ₂ O. Percentages are by weight.

Mineral wool generally consists of intertwined vitreous fibers. As a general rule, the mineral wool used does not contain any organic binder. It may, however, contain some when the flakes come from the recycling of construction site or factory waste, for example obtained by grinding mineral wool panels. The flakes may be blowing wool flakes, which normally do not contain an organic binder, but which may nevertheless contain organic additives, for example of the silicone or antistatic agent type. These additives are notably sprayed on the mineral wool at the time of fiberizing.

The plant wool comprises plant fibers preferably chosen from the group consisting of lignocellulosic fibers and cellulose fibers. The lignocellulosic fibers are preferably chosen from wood fibers, hemp fibers, linen fibers, sisal fibers, cotton fibers, jute fibers, coconut fibers, raffia fibers, fibers abaca, cereal straw, rice straw and their mixtures.

By flakes we mean pieces formed from agglomerates (or clusters) of tangled fibers of a certain size or dimension.

The flakes of mineral or vegetable wool preferably have a size between 0.1 and 10 cm, especially between 0.2 and 5 cm. The size of the flakes can in particular be determined by sieving. The size of the flakes is determined before blowing.

During blowing, the walls are arranged so as to extend along a vertical axis, over a height H (corresponding to the difference between the vertical coordinate H of the upper end and the lower vertical coordinate, taken by convention to be 0) . The cavity then opens out at the upper end of the walls. The cavity thus being accessible from above, it is possible to position the or each blowing nozzle at different locations in the cavity, corresponding to different vertical and/or horizontal coordinates. Prior to blowing, the or each nozzle is introduced into the cavity from above, between the two walls. The nozzle is therefore not introduced into the cavity through an orifice drilled in one of the walls. The or each nozzle is then positioned successively at different locations, each corresponding to increasing vertical coordinates, from the low location to the high location. In other words, the or each nozzle is positioned successively at different increasing heights in the cavity. The location of the nozzle is understood as that of its end, from which the flakes are blown. The vertical coordinate therefore corresponds to that of the end of the nozzle.

The vertical coordinate of the bottom location is preferably between 0 and H/3, in particular 0 and H/4, or even between H/10 and H/5 or between H/8 and H/6. The vertical coordinate of the high location is preferably between 3H/4 and H, in particular between 4H/5 and 9H/10.

Preferably, the method further comprises at least one intermediate blowing step in which the blowing nozzle is positioned at an intermediate location of the cavity having a vertical coordinate between the vertical coordinate of the bottom location and the vertical coordinate of the high location. The method even advantageously comprises a plurality of intermediate blowing steps, the blowing nozzle being positioned during each intermediate blowing step at a location in the cavity having a higher vertical coordinate than during the previous intermediate step.

The number of intermediate steps is preferably between 1 and 10, in particular between 2 and 5. It is adjusted according to the height H of the walls. The higher the height H, the more it is advisable to increase the number of intermediate steps. The number of intermediate stages can alternatively be very high, or even infinite, the nozzle then being moved continuously or almost continuously during blowing.

According to one embodiment, the walls are arranged during blowing so as to extend along a horizontal axis over a length L, and each blowing step is carried out by a single blowing nozzle and comprises the successive positioning of said blowing nozzle. blowing at at least two locations having the same vertical coordinate (i.e. positions of the same height) but different horizontal coordinates. The number of locations is preferably between 2 and 5, to be adjusted according to the length of the walls. The pitches are preferably distributed along the length. In such a mode, each blowing step (first, last, optionally intermediate) then comprises several successive steps in which the nozzle is positioned at the same height, but at different points, preferably distributed along the length.

According to another embodiment, the walls are arranged during blowing so as to extend along a horizontal axis over a length L, and each blowing step is carried out simultaneously by a plurality of blowing nozzles positioned at locations having the same vertical coordinate but different horizontal coordinates. The number of blowing nozzles is preferably between 2 and 5, to be adjusted according to the length of the walls.

These two embodiments make it possible to achieve optimal homogeneity in the case of very long walls, in particular lengths L greater than 1 m.

The flakes are blown downwards. The or each nozzle will therefore generally be oriented in a vertical plane. The orientation of the nozzle relative to the vertical axis can be adapted during blowing in order to improve the homogeneity of the insulating material along its length. The angle between the nozzle and the vertical axis, in a plane parallel to the plane of the walls, is preferably between 0 and 60°, in particular between 0 and 45°, in absolute value. For the same location (in particular high, low and/or intermediate), this angle can successively take several values, in particular in the aforementioned range, or even an infinity of values when the angle is varied continuously (particularly in the case of an oscillation relative to the vertical axis). Thus, for the same location, the angle between the blowing nozzle and the vertical axis, in a plane parallel to the plane of the walls, can successively take several values, in particular between 0 and 60° in absolute value.

Preferably an air-permeable closing means is arranged at the level of the upper end of the walls at least during the last blowing step, so as to close the cavity, said closing means comprising at least one orifice for the passage of the or each blowing nozzle. By “blocking” we mean that the blocking means cannot be penetrated by flakes. By "arranged at the upper end of the walls so as to close the cavity", we mean that the closing means extends between the two walls so as to fill the space which separates them at their end. high. The shutter means will therefore generally be arranged in a horizontal plane.

This arrangement makes it possible on the one hand to avoid flakes flying outside the cavity during the last step, when the or each nozzle is in the high position, and on the other hand to achieve high densities for the insulating material. , and therefore better thermal insulation properties. This mode does not exclude the possibility that the sealing means is also placed previously, during an intermediate blowing step, and in this case it remains in place during the last blowing step.

The sealing means is preferably an air-permeable membrane. It can also be a rigid material, for example wood, metal or plastic comprising at least one orifice, for example small holes. The membrane may in particular be a veil of glass or polymeric fibers. In particular, the membranes used in systems called “BIBS” (for Blow-in Blanket® Systems) can be used.

The diameter of the nozzle is preferably between 10 and 120 mm, in particular between 50 and 100 mm, or even between 60 and 80 mm. The air pressure is preferably between 100 and 300 mbar, especially between 150 and 250 mbar. The flake flow rate is preferably between 100 and 200 kg/h.

According to a preferred embodiment, the walls were obtained by additive manufacturing. In this case, the walls are preferably made of mortar or concrete. Such walls, due to their irregular structure due to the fact that they are formed of superimposed layers, contribute to improving the homogeneity of the insulating material.

Preferably, the method can even further comprise a preliminary step of constructing the walls by additive manufacturing. In this case, the walls are preferably made of mortar or concrete. In such an embodiment, this preliminary step preferably comprises mixing a dry mortar with mixing water so as to form a wet mortar, transporting said wet mortar to a print head, and depositing successively, by moving said print head, layers of mortar superimposed so as to form the walls. The wet mortar has a paste consistency and can be pumped and transported to the print head. Pumping is for example carried out using a screw pump. Transport typically takes place in a pipe. The print head notably includes a nozzle through which the wet mortar is extruded. The extrusion nozzle is preferably located less than 100 mm from the underlying layer. The printer is, for example, an industrial robot or a gantry, carrying the print head, and whose movement is controlled by a computer. The computer includes in particular a recording medium in which a set of data or 3D model is stored as well as instructions, which when executed by the computer lead the latter to control the movement (trajectory, speed, etc.) of the print head. The printing speed is typically 30 to 1000 mm/s, in particular 50 to 300 mm/s. The thickness (or height, since this is the dimension in the vertical direction) of the layers of mortar is preferably between 5 and 40 mm, in particular between 10 and 20 mm. The width of the mortar layers (corresponding to the thickness of the walls) is preferably between 10 and 300 mm, in particular between 20 and 100 mm.

Preferably, the density of the insulating material is between 20 and 70 kg/m ³ , in particular between 25 and 40 kg/m ³ , or even between 30 and 35 kg/m ³ .

The examples which follow, as well as the Figures, illustrate the invention in a non-limiting manner.

is a perspective view of a wall according to the invention.

is a sectional view schematizing an example of a method according to the invention.

has are sectional views schematizing steps of a process according to the invention.

There represents a wall according to the invention. In this case it is a wall 1 comprising two walls 3 and 5 facing each other so as to provide a cavity 7 filled with an insulating material 9. The walls 3 and 5, which extend in the vertical plane XZ, have a height H and a length L. In the coordinate system (X, Z), the upper end of the walls has the coordinate H.

The same elements are found in , which is a sectional view of the wall 1 according to the plane YZ, during the first blowing stage. The blowing nozzle 8 shown in solid lines schematizes this first blowing step, during which the blowing nozzle 8 is positioned at a low location in the cavity 7. The other blowing nozzle 8, shown in dotted lines, schematizes the last blowing step, during which the blowing nozzle 8 is subsequently positioned at a high location. The bottom and top positions of the different figures are here purely illustrative and can obviously be different from those shown, as explained further in this description. In this figure, as well as in the other figures, the locations (top, bottom and possibly intermediate) are schematized by dotted horizontal lines, corresponding to the vertical coordinates of the end of the nozzle 8 from which the flakes are blown.

Figures 3 to 8 are sectional views of the wall 1, but along the plane XZ (so that the walls 3 and 5 are not visible), and represent different stages of embodiments of a method according to the 'invention.

In is shown the first blowing step, in which the blowing nozzle 8 is positioned at a low location of the cavity 7. The illustrates an embodiment in which the blowing nozzle is then positioned at an intermediate location of the cavity 7, during an intermediate blowing step. There illustrates the last blowing step, in which the blowing nozzle 8 is positioned at a high location of the cavity 7. In the embodiment shown, an air-permeable closing means 11 is arranged at the level of the upper end of the walls 3 and 5, so as to close the cavity 7. The closing means 11 comprises an orifice for the passage of the blowing nozzle 8.

There illustrates an embodiment, in which each blowing step is carried out by a single blowing nozzle 8 and comprises the successive positioning of the blowing nozzle 8 at two locations having the same vertical coordinate but different horizontal coordinates. The blowing nozzle 8 shown in dotted lines illustrates the future positioning of the nozzle.

There illustrates an alternative embodiment, in which each blowing step is carried out simultaneously by a plurality of blowing nozzles 8 (here two), positioned at two locations having the same vertical coordinate but different horizontal coordinates.

There schematically illustrates an embodiment in which the angle, denoted α in the figure, between the blowing nozzle 8 and the vertical axis Z takes several values, typically between 0 and 45°.

Examples

Cavities 1 meter high H, 1 meter long L and 20 cm thick formed by walls were filled by blowing glass wool flakes (InsulSafe Plus Wood marketed by the company Saint-Gobain Isover) , the average density of insulating material being 35kg/m ³ . The nozzle diameter was 76 mm and the insulating material flow rate was 550 kg/h.

In an example of a method according to the invention (A), the nozzle was first positioned at approximately 1/3 of the height H then at approximately half-height, then finally at approximately 3/4 of the height H. In the last step, a perforated cover was placed so as to close the cavity. During blowing, the angle between the blowing nozzle and the vertical axis was varied, typically between 0 and 45°.

In a comparative example B, the nozzle was positioned fixedly at a high level of the cavity throughout the filling, with a zero angle relative to the vertical axis. In a comparative example C, this fixed angle was 45°.

The overall thermal conductivity of the walls was measured. The homogeneity of the insulating material was qualitatively evaluated by a radar measurement system analyzing the time interval between an electromagnetic wave signal (1.6 GHz) emitted by an antenna and that received after reflection by the insulating material, as well than its amplitude. A score ranging from 0 to 10 was assigned, 10 corresponding to perfect homogeneity.

Table 1 below summarizes the tests, giving the measured thermal conductivity value λ (in mW/m.K) and the homogeneity score N (out of 10).

	AHAS	BB	CVS
λλ	4141	4646	4545
NNOT	88	44	44

The method according to the invention therefore makes it possible, thanks to better homogeneity of deposition of the flakes in the cavity, to achieve lower overall thermal conductivities for the wall element. In these experimental tests, the walls were made of plywood but the same advantages were observed for walls made of concrete blocks, concrete and mortar.

Claims

Method for obtaining a wall (1) comprising two walls (3, 5) made of concrete blocks, concrete or mortar and facing each other so as to provide at least one cavity (7) filled with an insulating material (9 ) comprising flakes of mineral or vegetable wool, said method comprising blowing said flakes into said cavity (7) by means of a blowing nozzle (8), said walls (3, 5) being arranged during blowing so as to extend along a vertical axis (Z) from their lower end, of vertical coordinate 0, to their upper end, of vertical coordinate H, the cavity (7) opening out at said upper end and accessible from above , and said flakes being blown downwards, said method comprising a first blowing step in which the blowing nozzle (8) is positioned at a low location in the cavity having a vertical coordinate between 0 and H/2, then a last blowing step in which the blowing nozzle (8) is positioned at a high location in the cavity having a vertical coordinate between 2H/3 and H.
Method according to claim 1, in which, prior to blowing, the or each blowing nozzle (8) is introduced into the cavity (7) from above, between the two walls (3, 5).
Method according to one of the preceding claims, further comprising at least one intermediate blowing step in which the blowing nozzle (8) is positioned at an intermediate location of the cavity (7) having a vertical coordinate between the vertical coordinate of the bottom location and the vertical coordinate of the top location.
Method according to the preceding claim, comprising a plurality of intermediate blowing steps, the blowing nozzle (8) being positioned during each intermediate blowing step at a location in the cavity (7) having a higher vertical coordinate than during the previous intermediate stage.
Method according to the preceding claim, in which the number of intermediate steps is between 1 and 10, in particular between 2 and 5.
Method according to one of the preceding claims, in which the walls (3, 5) are arranged during blowing so as to extend along a horizontal axis (X) over a length L, and:
- each blowing step is carried out by a single blowing nozzle (8) and comprises the successive positioning of said blowing nozzle (8) in at least two locations having the same vertical coordinate but different horizontal coordinates, or
- each blowing step is carried out simultaneously by a plurality of blowing nozzles (8) positioned at locations having the same vertical coordinate but different horizontal coordinates.
Method according to one of the preceding claims, in which, for the same location, the angle (α) between the blowing nozzle (8) and the vertical axis (Z), in a plane parallel to the plane of the walls (3 , 5) successively takes several values, in particular between 0 and 60° in absolute value.
Method according to one of the preceding claims, in which an air-permeable closing means (11) is arranged at the upper end of the walls at least during the last blowing step, so as to close the cavity (7), said closing means (11) comprising at least one orifice for the passage of the or each blowing nozzle (8).
Method according to the preceding claim, in which the closing means (11) is an air-permeable membrane, in particular a veil of glass or polymeric fibers.
Method according to one of the preceding claims, in which the flakes of mineral or vegetable wool have a size of between 0.1 and 10 cm, in particular between 0.2 and 5 cm.
Method according to one of the preceding claims, in which the walls (3, 5) were obtained by additive manufacturing.
Method according to the preceding claim, further comprising a preliminary step of constructing the walls (3, 5) by additive manufacturing.
Wall (1) comprising two walls (3, 5) made of concrete blocks, concrete or mortar and facing each other so as to provide a cavity (7) filled with an insulating material (9) comprising flakes of mineral or vegetable wool , capable of being obtained by the process according to one of the preceding claims.
Wall (1) according to the preceding claim, in which the density of the insulating material (9) is between 20 and 70 kg/m 3 , in particular between 25 and 40 kg/m 3 .