EP4247771A2

EP4247771A2 - Earth-based facing panel

Info

Publication number: EP4247771A2
Application number: EP21806763.5A
Authority: EP
Inventors: Hugo Perez; Louis Perez
Original assignee: Norper SAS
Current assignee: Norper SAS
Priority date: 2020-11-17
Filing date: 2021-11-17
Publication date: 2023-09-27
Also published as: FR3116287B1; FR3116287A1; WO2022106499A3; FR3116288B1; WO2022106499A2; FR3116288A1

Abstract

The present invention relates to an earth-based facing panel the core of which comprises, optionally, between 1 and 20% by weight of a material having a silica content greater than 50% (by weight), an open porosity greater than 45%, a particle size of less than or equal to 5 mm, between 0.5 and 15% by weight of crystalliser; between 15 and 60% by weight of binding agent selected from slag, metakaolin and plaster, and optionally lime; and between 20 and 80% by weight of earth having a particle size of less than or equal to 5 mm; the invention also relates to a method for producing such a facing panel and a use of at least one crystalliser to produce an earth-based facing panel.

Description

Earth-based facing brick

This international application claims the priority of French patent applications FR2011804 and FR2109761 filed on November 17, 2020 and September 16, 2021 respectively.

Field of invention

The present invention relates to an earth-based facing plate.

State of the art

[0002] It is common to use plaster-based facing panels to make vertical or horizontal partitions such as, for example, partition walls or ceilings. These plates are composite plates with two outer layers (typically cardboard) and a plaster core.

The plaster, of chemical formula CaSCL, ^V 2 ELO, results from the calcination of natural or synthetic gypsum. In the presence of water, the calcined gypsum undergoes a hydration reaction and is transformed again into calcium sulphate dihydrate (CaSÛ4.2 H2O: gypsum). The plaster manufacturing process is therefore a very energy-intensive process, which is a problem in connection with the new environmental regulations.

[0004] Indeed, a new environmental regulation for new buildings will see the light of day this year in France (RE 2020), which regulation will impose to further improve the environmental performance of a building by taking into account not only the insulation but also the overall environmental impacts associated with this construction and therefore the energy cost of all the materials used.

[0005] In this context, new facing plates should be considered, the energy cost of which would be reduced.

[0006] Now, the answer to this problem is not so simple insofar as it is not enough to reduce the rate of gypsum since the standards impose for these plates mechanical stresses of resistance and bending under load.

[0007] In addition, a solution could only be viable if the material replacing the plaster is not more expensive or not much more, which again constitutes a problem in itself. Faced with all of these problems, no alternative to the plaster facing panel having satisfactory characteristics has not been obtained so far.

Summary of the invention

[0009] The inventors have now developed a new earth-based mixture forming the core and which makes it possible to obtain a facing plate that meets the standards in terms of resistance to mechanical stress and bending under load.

[00010] In addition, the inventors have developed a new earth-based mortar whose performance is improved while it uses lower proportions of lime, but also of crystallizer. The addition of a porous silica-based material makes it possible to achieve the desired performance of the final product, even when the mortar does not include a crystallizer.

[00011] At the same time, the plate obtained has a much more favorable energy balance than conventional plaster-based facing plates, which makes it much more attractive than current facing plates in connection with the future RE 2020 standard. .

[00012] Consequently, a first object of the invention relates to an earth-based facing plate, characterized in that the core comprises:

[00013] a) optionally between 1 and 20% by weight (relative to the total weight of the core) of a material having a silica content greater than 50% (by weight), an open porosity greater than 45%, a particle size of less than or equal to 5 mm, preferably 2 mm, and preferably between 1 and 10% and, in a particularly preferred manner, between 2 and 10%, for example between 2 and 5%;

[00014] b) between 0.5 and 15% by weight (relative to the total weight of the core) of crystallizer; preferably between 2 and 10%, especially between 3 and 8% and, in a particularly preferred manner, between 4 and 6%;

c) between 15 and 60% by weight of binder selected from slag, metakaolin and plaster and, optionally lime; preferably between 20 and 60% and, in a particularly preferred way, between 25 and 55%; and

[00016] d) between 80 and 20% by weight of an earth having a particle size less than or equal to 5 mm, preferably between 70 and 30% and, in a particularly preferred manner between 60 and 30% by weight.

[00017] According to a preferred embodiment, the facing plate according to the invention comprises two sheets (e.g. paper, cardboard, etc.) between which the core is placed.

A second object of the invention relates to a method of manufacturing such a facing plate comprising a forming step comprising the pouring of a main batch and the forming of the facing plate, a setting step and a drying step; wherein the main batch comprises water and earth, characterized in that the main batch comprises:

[00019] a) between 40 and 150 parts of water (relative to the total weight of the main batch), preferably between 50 and 100 parts of water and, in a particularly preferred manner, between 60 and 80 parts of water,

[00020] b) 100 parts of a composition (relative to the total weight of the main batch) comprising:

[00021] - optionally between 1 and 20% by weight of a material having a silica content greater than 50% (by weight), an open porosity greater than 45%, a particle size less than or equal to 5 mm, preferably 2mm;

[00022] - between 0.5 and 15% by weight of crystallizer (relative to the total weight of the composition);

[00023] - between 15 and 60% by weight of binder, preferably between 20 and 60% and, particularly preferably, between 25 and 55%; and

[00024] between 80 and 20% by weight of an earth having a particle size less than or equal to 5 mm, preferably between 70 and 30% and, in a particularly preferred manner between 60 and 30% by weight.

According to a preferred embodiment, the facing plate comprises two sheets between which the core is placed and the forming step then comprises: [00026] - the supply of a first sheet;

[00027] - spillage of a main batch;

[00028] - the supply of a second sheet; and

[00029] - the forming of the facing plate, in particular using an extruder or a press.

A third object of the invention relates to a use of at least one crystallizer for the manufacture of an earth-based facing plate.

Advantageously, the core of said facing plate comprises between 20 and 60% by weight of binder; and between 80 and 20% by weight of soil with a grain size less than or equal to 5 mm.

[00032] Also advantageously, the core of said facing plate comprises between 0.5 and 15% by weight (relative to the total weight of the core) of crystallizer.

Detailed description of the invention

The first object of the invention therefore relates to a facing plate whose core comprises:

[00034] a) optionally between 1 and 20% by weight of a material having a silica content greater than 50% (by weight), an open porosity greater than 45%, a particle size less than or equal to 5 mm, preferably at 2mm;

[00035] b) between 0.5 and 15% by weight (relative to the total weight of the core) of crystallizer; especially between 2 and 10% and preferably between 3 and 8% and, particularly preferably between 4 and 6%;

c) - between 15 and 60% by weight of binder, preferably between 20 and 60% and, particularly preferably, between 25 and 55%;

[00037] d) between 80 and 20% by weight of a soil having a particle size less than or equal to 5 mm, preferably between 70 and 30% and, in a particularly preferred manner between 60 and 30% by weight.

[00038] Advantageously, the porous and silica-rich material is chosen from the group comprising diatomaceous earth, waste glass wool or rock (eg cullet and fibres), refractory brick waste (e.g. dust and residues).

Preferably, the porous silica-rich material is diatomaceous earth, also known as kieselguhr. It is a siliceous sediment with very high porosity giving it significant liquid absorption properties. The presence of such a porous material in the mortar advantageously makes it possible to adjust the proportion of water and makes it possible to improve the performance of the material obtained.

[00040] Waste glass wool or refractory bricks, when they are ground, are also porous materials rich in silica which in particular make it possible to reinforce the binder function of the mortar.

[00041] Advantageously, the particle size of this material is less than 1 mm. Typically, this particle size is between 1 and 500 μm.

[00042] Preferably, the porous and silica-rich material has a silica content greater than 80% (by weight) and, in a particularly preferred manner, greater than 90%.

[00043] A porous material is a material containing pores or cavities of small size and which can contain one or more fluids (liquid or gas). A structure is said to have open porosity when the pores are interconnected, thus forming very fine channels. Such an open porosity structure makes water absorption possible.

The silica-rich material is a material whose so-called “open” porosity is greater than 45%. Porosity is a physical quantity between 0 and 100% (or between 0 and 1), which conditions the flow and retention capacities of a substrate. This open porosity is measured in a conventional way by mercury intrusion porosimetry, i.e. by a method consisting in penetrating mercury into the pores of a sample under increasing pressure.

[00045] Preferably again, the porous material rich in silica has an open porosity greater than 60% and, in a particularly preferred manner, greater than 80%, or even greater than 90%.

[00046] By "crystallizer", sometimes also called mineralizer, is meant compounds capable of forming, by a qualified reaction of mineralization, crystalline and insoluble complexes with the soluble compounds of the mortar (free lime). [00047] By way of example of such compounds, mention may be made, for example, of silicate salts, carbonate salts (eg sodium carbonate such as natron), alginate salts.

[00048] Such crystallizers are known for use in the waterproofing of concrete, in particular under the names PENETRON, XYPEX, VANDEX, mineralizer B HYDRO-MINERAL, etc.

Preferably, the term “crystallizer” is understood to mean a silicate salt.

[00050] The inventors have in fact demonstrated that this crystallizer makes it possible to obtain both good grip of the core of the plate and, simultaneously, good mechanical behavior, which is by no means obvious.

[00051] Consequently, the crystallizer is chosen from the group comprising sodium silicate, potassium silicate, calcium silicate, magnesium silicate, and mixtures thereof.

[00052] Preferably, the crystallizer comprises potassium silicate.

[00053] In connection with the binder, one will be chosen having a particle size less than or equal to 200 μm, preferably less than or equal to 100 μm.

[00054] The term "slag" means the slag formed during the melting or elaboration of the metal by the liquid process. It is a mixture composed mainly of silicates, aluminates and lime with various metal oxides except iron oxides.

[00055] By "metakaolin" is meant the product of a calcination of kaolin and/or kaolin clay.

[00056] The term “plaster” generally means both set plaster, that is to say calcium sulphate dihydrate, and unset plaster, that is to say calcium sulphate hemihydrate. . We can just as well use classic plaster, machine plaster, pink plaster of Paris, etc...

[00057] By “lime” is meant artificial lime which essentially comprises calcium and magnesium oxide and/or calcium and magnesium hydroxide. Advantageously, lime is chosen from the group comprising hydraulic lime and aerial lime.

[00058] Now, when the binder comprises lime, the core comprises between 0 and 25% by weight (relative to the total weight of the core).

[00059] According to a preferred embodiment, the binder is plaster.

According to another preferred embodiment, the binder is slag with, optionally, lime.

[00061] “Soil” means soil from earthworks or excavation (quarry) operations, or even crushed deconstruction materials, excluding topsoil.

By deconstruction material is meant concrete, plaster, stone or even mortar.

[00063] Advantageously, the earth is chosen from the group comprising earth resulting from earthworks or excavation (quarry) operations.

[00064] This soil may therefore present a very great diversity of nature depending on the site from which it comes. Such soil may include gypsum, silt, limestone, silica, clay and mixtures thereof. Preferably, said earth is not gypsum.

Preferably, said earth will incorporate a clay content of less than or equal to 50% by weight, preferably less than or equal to 25% and, in a particularly preferred manner, less than or equal to 10%. Such a content can be determined by a particle size method such as that described in standard NF X31-107.

[00066] Now, the earth does not come from sand quarries or aggregate quarries (virgin aggregates).

[00067] In addition, earth that has undergone at most one pre-treatment by grinding, sorting (e.g. depending on the hue), sieving and/or drying before being mixed with the other components of the earth mortar is preferred. It should be noted that the earth used has therefore not undergone any chemical pre-treatment, such as a pre-treatment with a surfactant, so as to modify its structure and allow its liquefaction.

[00068] Advantageously, the soil used will have a smaller particle size or equal to 3 mm, for example less than or equal to 2 mm, and preferably less than or equal to 1 mmm.

[00069] According to a particular embodiment, the earth comprises clay.

[00070] Indeed and as described in patent FR 2916462 Bl, clay makes it possible to significantly improve the acoustic performance of the facing plate by increasing the capacity of the plate to limit the propagation of sound waves.

[00071] Advantageously, the core comprises, as earth, between 5 and 50% clay, preferably between 5 and 25% clay (relative to the total weight of the core).

As clay, mention may be made of phyllosilicates comprising in particular as clays, antigorite, chlorite, dickite, greenalite, hallosysite, illite, kaolinite, montmorillonite, nacrite, sepiolite, smectite and vermiculite.

[00073] According to a preferred embodiment, the core of the facing panel further comprises fibers.

[00074] The term "fibers" means both synthetic fibers (eg polypropylene or polyethylene fibers, glass fibers, carbon fibers, etc.) and natural fibers (eg cellulose fibers).

The fibers in question can be short (3 to 6 mm on average) or long (10 to 24 mm on average) or of intermediate dimensions.

Advantageously, the core comprises between 0.1 and 20% by weight (relative to its total weight), preferably between 0.5 and 10% by weight and, in a particularly preferred manner, between 0.5 and 5% by weight.

[00077] Preferably, the fibers are cellulose fibers (eg paper or cardboard pulp).

The facing plate according to the invention has a thickness adapted to the intended use.

[00079] Generally, the facing plate has a thickness of between 6 and 25 mm, preferably between 10 and 20 mm.

[00080] The most common thickness on the market is 12.5 mm with plates marketed under the name “BAI 3”. [00081] Now, and preferably, the facing plate according to the invention comprises two sheets between which the core is placed. Such a plate is then suitable for making partitions, linings and/or ceilings.

[00082] The sheets conventionally used are typically made of cellulose (paper, recycled paper or cardboard) or inorganic fiber (for example fiberglass).

[00083] Preferably, the sheets are made of cellulose.

[00084] In the case of “BA 13” plates, they typically have a thickness of paper on each side of 0.3 mm and therefore a thickness of the core of 11.9 mm. The paper is for example a paper with a weight of 180 g/m ² .

[00085] Finally, the core can incorporate other additives to either improve some of its properties (e.g. water repellents, flame retardants, biocides and reinforcing agents), or to facilitate its production (processability additives)

[00086] A second object of the invention relates this time to a method of manufacturing such a facing plate.

[00087] Such a method comprises a forming step (discharge of a main batch and forming of the facing plate), a setting step and a drying step; in which the main batch comprises:

[00088] a) between 40 and 150 parts of water (relative to the total weight), and

[00089] b) 100 parts of a composition comprising:

[00090] - between 1 and 20% by weight of a material having a silica content greater than 50% (by weight), an open porosity greater than 45%, a particle size less than or equal to 5 mm, preferably 2 mm;

- between 0.5 and 15% by weight of crystallizer (relative to the total weight of the composition);

- between 15 and 60% by weight of binder, preferably between 20 and 60% and, particularly preferably, between 25 and 55%; [00093] and

[00094] - between 80 and 20% by weight of an earth having a particle size less than or equal to 5 mm, preferably between 70 and 30% and, particularly preferably between 60 and 30% by weight.

[00095] The composition is equivalent to that of the core of the facing panel described above.

[00096] The main mix may include other additives, such as those likely to improve the characteristics of the core and described above, but also processability additives allowing the properties of the mix to be improved depending on the manufacturing conditions. .

[00097] Processability additives well known to those skilled in the art may in particular be adhesion agents, foaming agents, fluidifying agents, thickening agents, wetting agents, dispersing agents, setting-regulating agents ( accelerators or retarders).

As adhesion agents, mention may be made of poly(vinyl acetate), a poly(vinyl alcohol), a starch, in particular previously treated with an acid or pre-gelatinized, a dextrin or a flour vegetable, in particular wheat or corn.

As foaming agents, mention may be made of surfactants such as those described in international applications WO 2002/024595A1 and WO 2009/085635 or, in patent application FR 3059662.

[000100] By way of example of thinning agents, mention may be made of Poly Melamine Sulfonates (PMS), Poly Naphthalene Sulfonates (PNS) and Poly Carboxylate Poly oxy ethylene (PCP).

[000101] By way of example of thickening agents, mention may be made of cellulose derivatives such as for example carboxymethylcellulose, methylhydroxypropylcellulose or methylhydroxyethylcellulose, vegetable gums such as for example acacia, tragacanth, carob, dextran, diutane, gellan , guar, scleroglucan, xanthan, welan, polyethylene oxides, starch or its derivatives, gelatin, polysaccharides, hydrocolloids, agar and carrageenans. [000102] Mention may be made, as examples of wetting agents, of alcohols, polyols and in particular diols.

[000103] By way of examples of dispersing agents, mention may be made of carboxylic polymers or their salts;

[000104] As setting regulating agents of the accelerator type, mention may be made of gypsum germ, K2SO4, sulphate salt, Bali Milled Accelerator (mixture of 50% gypsum, 40% starch and 10% of calcium lignosulphate For set regulators of the retarding type, mention may be made of degraded or non-degraded proteins, sugars or polyacrylates.

[000105] A third object of the invention relates to a use of at least one material having a silica content greater than 50% (by weight), an open porosity greater than 45% for the manufacture of a facing plate soil-based as previously described.

[000106] A fourth object of the invention relates to a use of at least one crystallizer for the manufacture of an earth-based facing plate as described above.

[000107] Advantageously, the core of said facing plate comprises between 20 and 60% by weight of binder and between 80 and 20% by weight of earth having a particle size less than or equal to 5 mm.

[000108] Also advantageously, the core of said facing plate comprises between 2 and 10% by weight (relative to the total weight of the core) of crystallizer.

[000109] Preferably, the crystallizer is a silicate salt which can be chosen from the group comprising sodium silicate, potassium silicate, calcium silicate, magnesium silicate, and mixtures thereof and, in a particularly preferred manner , the crystallizer comprises potassium silicate.

[000110] Other characteristics, details and advantages of the invention will emerge more clearly from the detailed description given below by way of indication.

[000111] Examples

[000112] Batches comprising 100 parts by weight of the compositions described in Table I and 75 parts of water were prepared to produce facing boards with ground base.

[000113] [Table 1]

[000114] Each mix is then cast on a first sheet of paper (180 g/m ² ) so as to form a core of 12 mm, then a second sheet, identical to the first, is positioned above the main mix.

[000115] The forming step is then carried out using a press applied to the assembly.

[000116] Once the plates have been obtained, tests of resistance to bending, thermal resistance, impact resistance and resistance to compression are carried out on the various plates.

[000117] Although earth-based, the facing plates according to the invention have entirely satisfactory properties for use in construction. It should be noted that the use of a silica-based material (diatomaceous earth) considerably improves the properties of earth-based facing plates.

Claims

CLAIM

1. An earth-based facing plate, characterized in that the core comprises: a) optionally between 1 and 20% by weight (relative to the total weight of the core) of a material having a silica content greater than 50% (by weight), an open porosity greater than 45%, a particle size less than or equal to 5 mm, b) between 0.5 and 15% by weight (relative to the total weight of the core) of crystallizer , preferably between 2 and 10%; c) between 15 and 60% by weight of binder selected from slag, metakaolin and plaster and, optionally lime; preferably between 20 and 60%; and d) between 80 and 20% by weight of earth having a particle size less than or equal to 5 mm, preferably between 70 and 30% by weight.

2. The facing plate according to claim 1, characterized in that the binder is plaster.

3. The facing plate according to claim 1, characterized in that the binder is slag and optionally lime.

4. The facing plate according to claim 1, characterized in that the material having a silica content greater than 50% (by weight), an open porosity greater than 45%, a particle size less than or equal to 5 mm is diatomaceous earth.

5. The facing plate according to any one of the preceding claims, characterized in that said earth comes from earthworks or excavation (quarry) operations, or even crushed deconstruction materials, excluding earth vegetable, and in that it comprises gypsum, silt, limestone, silica, clay or mixtures thereof.

6. The facing plate according to any one of the preceding claims, characterized in that said earth will incorporate a clay content of less than or equal to 50% by weight, preferably less than or equal to 25% and, particularly preferably, less or equal to 10%.

7. The facing plate according to any one of the preceding claims, characterized in that it comprises two sheets between which the core is arranged.

8. The facing plate according to any one of the preceding claims, characterized in that the crystallizer is chosen from the group comprising silicate salts, carbonate salts and alginate salts.

9. A method of manufacturing an earth-based facing board comprising a forming step, comprising pouring a main batch and forming the facing board, a setting step and a drying step; wherein the main batch comprises water and earth, characterized in that it comprises: a) between 40 and 150 parts of water (by total weight), and b) 100 parts of a composition including:

- optionally, between 1 and 20% by weight of a material having a silica content greater than 50% (by weight), an open porosity greater than 45%, a particle size less than or equal to 5 mm;

- between 15 and 60% by weight of binder selected from slag, metakaolin and plaster and, optionally lime; and

- between 80 and 20% by weight of soil with a grain size less than or equal to 3 mm.

10. The method according to the preceding claim characterized in that it is aimed at the manufacture of a facing plate comprises two sheets between which the core is arranged and the forming step then comprises:

- supply of a first sheet;

- spillage of a main batch;

- the supply of a second sheet; and

- the forming of the facing plate, in particular using an extruder or a hurry.

11. A use of at least one crystallizer, preferably a silicate salt, for the manufacture of an earth-based facing plate as defined in any one of claims 1 to 8.