Insulating wall arrangement

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

[0001] The present invention relates to the field of construction. More specifically, it relates to an insulating wall and its method of production.

[0002] It is known to fill cavities in building elements, such as walls or parts of walls, with insulating materials, such as mineral wool or foams, whether inorganic (e.g. cement foams) or organic (e.g. polyurethane foams).

[0003] These different solutions are not without drawbacks, however. The filling of cavities with the insulating material is not always uniform, leading to the creation of thermal bridges and therefore to a deterioration in thermal insulation performance. These inconsistencies can occur over time or during the transport of construction elements to the construction site, in the case of prefabricated elements. For example, mineral wool-based materials can tend to settle, and inorganic foams sometimes shrink. Organic foams sometimes exhibit poorly controlled expansion during installation. Some known solutions are also not suitable for automation.

[0004] The invention aims to overcome these drawbacks by proposing a wall which has a lower overall thermal conductivity, thanks to better homogeneity of the filling of the cavity.

[0005] 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 vertical coordinate 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 lower 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 high location in the cavity having a vertical coordinate between 2H / 3 and H.,

[0006] 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.

[0007] The method 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.

[0008] The various preferred features presented in the present description are applicable to both the method and the construction element.

[0009] The wall may be a load-bearing wall or a partition wall. The wall is preferably a wall erected directly on the construction site of the building for which the wall is intended. The method then includes a preliminary step of erecting said wall on the construction site.

[0010] The walls are made of concrete blocks, concrete, or mortar. Concrete blocks are made of 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 different materials. The walls are therefore not made of a breathable material.

[0011] The walls are generally flat and parallel to each other, but other geometries are of course possible, particularly when obtained by additive manufacturing, as described in more detail later in the text.

[0012] The walls may contain one or more cavities. In the latter case, it is best to fill all the cavities.

[0013] 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. For example, the wall may 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 – excluding the thickness of the walls) is preferably between 5 and 50 cm, in particular between 10 and 40 cm, or even between 15 and 30 cm.

[0014] 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 may consist of mineral or vegetable wool flakes.

[0015] The mineral wool is preferably selected from glass wools, slag wools, rock wools 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 SiO2, 5 to 40% by weight of CaO+MgO, 0-20% by weight of Na2O+K2O, 0-30% by weight of Al2O3 and 0-15% by weight of Fe2O3.

[0016] The use of glass wool generally allows better thermal insulation performance to be achieved, in particular thanks to a lower density.

[0017] Glass wool is generally formed by electrical or flame fusion of a mixture of powdered raw materials and cullet (recycled glass), followed by fiberization, particularly by internal centrifugation using a fiberizing plate. The fibers of the glass wool preferably have a chemical composition comprising 50-75% SiO2, 10 to 25% Na2O+K2O, 5 to 20% CaO+MgO, 0-8%, especially 0-3% Al2O3 and 0 to 10%, especially 2 to 8% B2O3 (the percentages being by weight).

[0018] Rock and slag wools are generally formed by cupola melting of raw materials in the form of blocks and / or briquettes, or by electric melting or submerged burners of powdered materials, followed by fiberization by external centrifugation using a plurality of rotors. Rock wool fibers preferably have a chemical composition comprising 30-50% SiO2, 10-26% Al2O3, 15-40% CaO+MgO, 0-5% Na2O+K2O and 3-15% Fe2O3. Slag wool fibers preferably have a chemical composition comprising 30-45% SiO2, 5-18% Al2O3, 30-60% CaO+MgO and 0-3% Na2O+K2O. The percentages are by weight.

[0019] Mineral wool is generally made up of interwoven vitreous fibers. Generally, the mineral wool used does not contain an organic binder. However, it may contain organic binders when the flakes are recycled from construction or factory waste, for example, obtained by crushing mineral wool panels. The flakes may be blown wool flakes, which do not normally contain an organic binder, but may nevertheless contain organic additives, such as silicone or antistatic agents. These additives are sprayed onto the mineral wool during fiberization.

[0020] Vegetable wool comprises vegetable fibers preferably selected from the group consisting of lignocellulosic fibers and cellulosic fibers. The lignocellulosic fibers are preferably selected from wood fibers, hemp fibers, flax fibers, sisal fibers, cotton fibers, jute fibers, coconut fibers, raffia fibers, abaca fibers, cereal straw, rice straw and mixtures thereof.

[0021] Flakes are pieces formed from agglomerates (or clusters) of tangled fibers having a certain size or dimension.

[0022] Mineral or vegetable wool flakes preferably have a size between 0.1 and 10 cm, particularly between 0.2 and 5 cm. The size of the flakes can be determined by sieving. The size of the flakes is determined before blowing.

[0023] 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, conventionally taken as 0). The cavity then opens out at the upper end of the walls. Since the cavity is thus 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 lower location to the upper location.In other words, the nozzle or nozzles are 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.

[0024] The vertical coordinate of the low 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.

[0025] 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 low 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 of the cavity having a higher vertical coordinate than during the previous intermediate step.

[0026] The number of intermediate stages is preferably between 1 and 10, particularly 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 stages. The number of intermediate stages can alternatively be very high, or even infinite, the nozzle then being moved continuously or almost continuously during blowing.

[0027] 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 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 locations are preferably distributed along the length. In such an embodiment, 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.

[0028] 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.

[0029] 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.

[0030] The flakes are blown downwards. The nozzle or nozzles 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 in the 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 infinite number of values ​​when the angle is varied continuously (in particular 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.

[0031] Preferably, an air-permeable sealing means is arranged at the upper end of the walls at least during the last blowing step, so as to seal the cavity, said sealing means comprising at least one orifice for the passage of the or each blowing nozzle. By "sealing", it is meant that the sealing means cannot be crossed by flakes. By "arranged at the upper end of the walls so as to seal the cavity", it is meant that the sealing means extends between the two walls so as to fill the space which separates them at their upper end. The sealing means will therefore generally be arranged in a horizontal plane.

[0032] This arrangement makes it possible on the one hand to prevent flakes from flying out of 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 consequently better thermal insulation properties. This mode does not exclude the possibility that the sealing means is also arranged previously, during an intermediate blowing step, and in this case it remains in place during the last blowing step.

[0033] 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 can be, in particular, a glass or polymer fiber veil. In particular, membranes used in systems called "BIBS" (for Blow-in Blanket® Systems) can be used.

[0034] The nozzle diameter 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, in particular between 150 and 250 mbar. The flake flow rate is preferably between 100 and 200 kg / h.

[0035] 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.

[0036] Preferably, the method may 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 successively depositing, by moving said print head, superimposed layers of mortar so as to form the walls. The wet mortar has a pasty consistency and can be pumped and transported to the print head. The pumping is for example carried out by means of a screw pump. The transport is typically carried out in a pipe. The print head notably comprises 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 mortar layers 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.

[0037] Preferably, the density of the insulating material is between 20 and 70 kg / m 3, especially between 25 and 40 kg / m 3 , or even between 30 and 35 kg / m 3 .

[0038] The following examples, as well as the Figures, illustrate the invention in a non-limiting manner.

[0039] is a perspective view of a wall according to the invention.

[0040] is a sectional view schematically illustrating an example of a method according to the invention.

[0041] are sectional views diagrammatically showing steps of a method according to the invention.

[0042] La represents a wall in accordance with 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 (X, Z) reference frame, the upper end of the walls has the coordinate H.

[0043] The same elements are found in, which is a sectional view of the wall 1 along the YZ plane, during the first blowing step. 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 low and high positions of the different figures are here purely illustrative and may 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 shown diagrammatically by dotted horizontal lines, corresponding to the vertical coordinates of the end of the nozzle 8 from which the flakes are blown.

[0044] Figures 3 to 8 are sectional views of wall 1, but along the XZ plane (so that walls 3 and 5 are not visible), and represent different stages of embodiments of a method according to the invention.

[0045] The first blowing step is shown, in which the blowing nozzle 8 is positioned at a low location in the cavity 7. The illustrates an embodiment in which the blowing nozzle is then positioned at an intermediate location in the cavity 7, during an intermediate blowing step. The illustrates the last blowing step, in which the blowing nozzle 8 is positioned at a high location in the cavity 7. In the embodiment shown, an air-permeable sealing means 11 is arranged at the upper end of the walls 3 and 5, so as to seal the cavity 7. The sealing means 11 comprises an orifice for the passage of the blowing nozzle 8.

[0046] Illustrates an embodiment, in which each blowing step is performed 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.

[0047] 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.

[0048] Schematically illustrates an embodiment in which the angle, noted α in the figure, between the blowing nozzle 8 and the vertical axis Z takes several values, typically between 0 and 45°.

[0049] Examples

[0050] 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 the insulating material being 35 kg / m 3 The nozzle diameter was 76 mm and the flow rate of insulating material was 550 kg / h.

[0051] 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, and finally at approximately 3 / 4 of the height H. In the last step, a perforated cover was arranged 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°.

[0052] In comparative example B, the nozzle was positioned fixedly at a high level of the cavity throughout the filling, with a zero angle to the vertical axis. In comparative example C, this fixed angle was 45°.

[0053] The overall thermal conductivity of the walls was measured. The homogeneity of the insulating material was qualitatively assessed using a radar measuring system that analyzed the time interval between an electromagnetic wave signal (1.6 GHz) emitted by an antenna and the one received after reflection by the insulating material, as well as its amplitude. A score ranging from 0 to 10 was assigned, with 10 corresponding to perfect homogeneity.

[0054] Table 1 below summarizes the tests, giving the measured thermal conductivity value λ (in mW / mK) and the homogeneity score N (out of 10).

[0055] ABCλ414645N844

[0056] The method according to the invention therefore makes it possible, thanks to a 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 lower location of the cavity having a vertical coordinate between 0 and H / 2,then a final 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 low location and the vertical coordinate of the high 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 step. 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) at 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 sealing means (11) is arranged at the upper end of the walls at least during the last blowing step, so as to seal the cavity (7), said sealing 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 sealing means (11) is an air-permeable membrane, in particular a veil of glass or polymer fibers. Method according to one of the preceding claims, in which the mineral or vegetable wool flakes 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) have been obtained by additive manufacturing. Method according to the preceding claim, further comprising a prior 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 method 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 , especially between 25 and 40 kg / m 3 .

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