Dry construction composition wet-sprayable by means of a screw pump and containing a binder and a biosourced filler, and preparation and uses of such a composition

Abstract

A dry construction composition is easily wet-sprayable by means of a screw pump, thus forming, after hardening, a durably mechanically resistant insulating material (λ<0.1 W.Math.m−1.Math.K−1). The composition contains: —A— at least one binder, itself including: —A1— at least one main binder containing lime and/or at least one alumina source and/or at least one calcium sulfate source, preferably at least one alumina source, —A2— at least one water-retaining agent, and —A3— preferably at least one surfactant; and —B— at least one biosourced filler, preferably of plant origin. The ratio B/A (liters/kg) is between 2 and 9. The composition is intended to be mixed with water in a water/binder ratio —A— of no lower than 0.8. Also disclosed is a wet composition, the preparation thereof, to the binder —A— taken in isolation, and to a method of spraying the composition onto a horizontal or vertical substrate or by molding.

Claims

1. A dry mortar composition, wet-sprayable by means of a screw pump, enabling the production of an insulating mortar, the dry mortar composition comprising: —A— at least one binder, itself comprising: —A1— at least one primary binder comprising lime and at least one alumina source, wherein a dry weight ratio of the alumina source to the lime is less than or equal to 1.5; —A2— at least one water-retaining agent; —B— at least one biosourced filler of plant origin; the B/A ratio—the volume of dry filler —B— in litres/mass of dry binder —A— in kg—being comprised between 4 and 7.9 L/kg; wherein the dry mortar composition is configured such that when it is mixed with water at a water/A weight ratio comprised between 0.8 and 5, it forms a wet-sprayable composition that is pumpable in a screw pump, the wet-sprayable composition having a setting time of between 1 and 24 hours that is effective to produce an insulating mortar that has a thermal conductivity λ of less than or equal to 0.1 W/m.Math.K; the biosourced filler —B— of plant origin, is essentially composed of cellulose, hemicellulose and/or lignin, said filler comprising at least one component, fibres, fibrils, dust, powder, chips said component originating from at least part of at least one plant raw material, in at least one particulate form, the at least one plant raw material is hemp; and the binder —A— comprises—in dry weight/weight %—: the at least one primary binder—A1—: 5-95; of which: the lime: 10-95; the at least one alumina source: 1-90; the at least one water-retaining agent—A2—: 0.1-5; —A3— surfactant: 0.01-1; —A4— secondary binder 0-85; —A5— lubricating mineral filler with a particle size d90 less than 100 μm: 0-40; —A6— mineral spacing filler with a particle size d90 greater than or equal to 100 μm: 0-40; —A7— water-repellent additive: 0-1.5; —A8— retarding additive: 0-3; —A9— accelerating additive: 0-3; and —A10— thickening additive: 0-2.

2. The composition according to claim 1, wherein the dry mortar composition further comprises water mixed therein at a water/A weight ratio comprised between 0.8 and 5.

3. The composition according to claim 1, wherein the at least one alumina source is selected from the following: geopolymer cements, slags, quick-setting cements, calcium aluminate cements (CAC), calcium sulphoaluminate (CSA) cements or mixtures of these species, used alone or in a mixture.

4. The composition according to claim 1, wherein the at least one water-retaining agent —A2— is selected from polysaccharides.

5. The composition according to claim 1, wherein the at least one secondary binder —A4— is different from the at least one binder —A1— and selected from Portland cements, quick-setting cements, slags, geopolymer cements, natural pozzolans, sodium silicates, potassium silicates, lithium silicates, organic binders or mixtures thereof.

6. Wet composition obtained from the composition according to claim 1, characterized in that it is pumpable in a machine fitted with a screw pump with an air gap (E) between the rotor (20) and the stator (18) of between 4 and 30 mm.

7. Hardened mortar obtained from the wet composition according to claim 6, characterized by a thermal conductivity λ less than or equal to 0.15 W/m.Math.K.

8. External Thermal Insulation (ETI) or Internal Thermal Insulation (ITI) system comprising hardened mortar according to claim 7 and applied in layer(s) over a total thickness comprised between 2 and 30 cm, and coated with a waterproof render of a minimum thickness of 10 mm, characterized in that the hardened mortar comprises lime and at least one alumina source and in that said system passes the test for ETI in accordance with EOTA standard ETAG 004.

9. Method for applying an insulating mortar comprising the following steps: 1. Preparing a mixture of water and the dry composition according to claim 1, that is, comprising the binder —A— and the filler of plant origin —B—, in the water/binder —A— weight ratio given below:
0.8≤[Water/A]≤5; 2. Pumping the mixture prepared in step 1 by means of a screw pump, 3.1 Spraying the mixture prepared in step 1 .fwdarw.onto a vertical or inclined substrate, .fwdarw.to fill a timber- or metal-framed structure on site, .fwdarw.for to produce prefabricated walls; or 3.2 Spraying and spreading the mixture on a horizontal surface to form a screed; or 3.3. Pouring the mixture prepared in step 1 into formwork to produce a wall, to fill between two partitions, or into a mould to produce a prefabricated element.

10. The composition according to claim 1, wherein the at least one water-retaining agent —A2— is selected from the group consisting of cellulose ethers; starch ethers; mixtures of cellulose ethers and starch ethers; methyl celluloses; hydroxypropyl celluloses; hydroxyethyl celluloses; methyl hydroxypropyl celluloses; methyl hydroxyethyl celluloses; mixtures of at least one of methyl celluloses, hydroxypropyl celluloses, hydroxyethyl celluloses, methyl hydroxypropyl celluloses, methyl hydroxyethyl celluloses; modified guar ethers; unmodified guar ethers; mixtures of modified guar ethers and unmodified guar ethers; and mixtures thereof.

11. The composition according to claim 2, wherein the thermal conductivity λ is in the range of from 0.074 W/m.Math.K to 0.08 W/m.Math.K.

12. The composition according to claim 2, wherein the B/A ratio is in the range of from 4.6 and 7.5 L/kg.

13. The composition according to claim 1, wherein the dry weight ratio of the alumina source to the lime is less than or equal to 1.3.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) Binder —A—

(2) The binder —A— according to the invention is generally mineral and comprises at least one primary binder A1 and optionally a secondary binder —A4— different from the binder —A1—

(3) —A1— Primary Binder

(4) The primary binder —A1— comprises lime and/or one alumina source and/or one calcium sulphate source.

(5) According to a preferred embodiment of the invention, the primary binder A1 comprises lime and at least one alumina source.

(6) In a remarkable variant of this preferred embodiment, the dry weight ratio [(alumina source)/(lime)] is less than or equal to—in increasing order of preference—2.3; 2.1; 1.9; 1.7; 1.5; 1.3; 1.1; 0.9.

(7) The lime is an air lime and/or hydraulic lime.

(8) The air lime in question is of the type that complies with NF EN 459-1, preferably selected from the group comprising—ideally constituted by—: a calcium air lime (CL) containing calcium oxide (CaO) and/or calcium hydroxide (Ca(OH).sub.2), the sum of CaO+MgO of which is at least 70% and the MgO content is <5%; dolomite lime (DL) containing magnesium calcium oxide (CaO MgO) and/or magnesium calcium hydroxide (Ca(OH).sub.2Mg(OH).sub.2), the sum of CaO+MgO of which is at least 80% and the MgO content of which varies from 5% to more than 30%; or mixtures thereof.

(9) The air lime can be in various forms such as a paste, a powder or, for quick lime, the rock itself.

(10) The hydraulic lime in question is of the type that complies with NF EN 459-1. Any mixture of lime of any type whatever, in any form whatever, can contain the composition according to the invention.

(11) The alumina source is preferably selected from the following species: calcium aluminate cements (CAC), calcium sulphoaluminate (CSA) cements, binders with high alumina-rich cementitious phase content or mixtures of these species used alone or in a mixture.

(12) According to a variant, the alumina source is selected from the following species: quick-setting cements (for example natural quick-setting cements), geopolymer cements, slag, calcium aluminate cements (CAC), calcium sulphoaluminate (CSA) cements or mixtures of these species used alone or in a mixture.

(13) According to another variant, the alumina source is selected from the hydraulic binders comprising: at least one phase selected from C.sub.3A, CA, C.sub.12A.sub.7, C.sub.11A.sub.7CaF.sub.2, C.sub.4A.sub.3$ (Ye'elimite), C.sub.2A.sub.(1-x)F.sub.x (where C.fwdarw.CaO; A.fwdarw.Al.sub.2O.sub.3; F.fwdarw.Fe.sub.2O.sub.3 and x belonging to]0, 1]), hydraulic amorphous phases having a molar ratio C/A comprised between 0.3 and 15, and such that the combined Al.sub.2O.sub.3 content of these phases is comprised between: 3 and 70% by weight of the total of the hydraulic binder, preferably between 7 and 50% by weight, even more preferably between 20 and 30% by weight.

(14) CACs are cements containing a C.sub.4A.sub.3$, CA, Cl.sub.2A.sub.7, C.sub.3A or C.sub.11A.sub.7CaF.sub.2 mineralogical phase or mixtures thereof, such as for example Ciments Fondu®, sulphoaluminate cements, calcium aluminate cements in accordance with European Standard EN 14647 of December 2006, the cement obtained from the clinker described in patent application WO2006/018569 or mixtures thereof.

(15) Sulphoaluminate clinkers are obtained from a mixture of calcium carbonate in calcareous form, bauxite or another alumina source (for example dross type by-product) and calcium sulphate, which is either gypsum, anhydrite or hemihydrate or mixtures thereof. The specific constituent at the end of the production process is Ye'elimite, C.sub.4A.sub.3$. In particular, quick-setting cements or sulphoaluminate cements with Ye'elimite contents comprised between 3% and 70% can be used, as may be sold by Vicat, Italcementi, Lafarge-Holcim, Polar Bear, Liu Jui, Readerfast.

(16) For example a quick-setting natural cement is constituted by a clinker containing: 0% to 35% C.sub.3S; 10% to 60% C.sub.2S; 1% to 12% C.sub.4AF; 1% to 10% C.sub.3A; 5% to 50% CaCO.sub.3 (calcite); 10% to 15% Ca.sub.5(SiO.sub.4).sub.2CO.sub.3 (spurrite); 3 to 10% sulphate phases: Ye'elimite (C.sub.4A.sub.3$), Langbeinite K.sub.2Mg.sub.2(SO.sub.4).sub.3, anhydrite (C$); and 10 to 20% lime, periclase, quartz and/or one or more amorphous phases.

(17) According to another variant, the alumina source is selected from hydraulic binders having an alumina content (expressed as Al.sub.2O.sub.3) comprised within the following ranges—in dry weight % and in increasing order of preference—[20; 70]; [25; 65]; [30; 72]; [35; 58].

(18) Advantageously, the calcium sulphate source is selected from the anhydrites, gypsums, calcium hemihydrates, supersulphated cements and mixtures thereof. The natural or synthetic calcium sulphate source is selected from the anhydrites, gypsums, calcium hemihydrates or mixtures thereof used alone or in a mixture.

(19) —A2— Water-Retaining Agent

(20) Preferably, the water-retaining agent —A2— has a water retention greater than or equal to—in increasing order of preference—50, 60, 70, 80, 90%, according to the retention measuring method M2, this water-retaining agent preferably being selected from the polysaccharides, and even more preferably from the group comprising, or even better constituted by, the cellulose or starch ethers and mixtures thereof; the -uloses, hydroxyethyl celluloses, hydroxypropyl celluloses, methyl hydroxypropyl celluloses, methyl hydroxyethyl celluloses and mixtures thereof; modified or unmodified guar ethers and mixtures thereof; or a mixture of these different species.

(21) The water-retaining agent A2 preferably has a 2% viscosity in water, measured using a Haake Rotovisco RV100 viscometer, shear rate of 2.55 s.sup.−1 at 20° C., comprised between 5,000 and 70,000 cP, preferably between 20,000 and 50,000.

(22) The water-retaining agent A2 has the property of retaining the mixing water before setting. The water is thus kept in the mortar or concrete mixture, which gives it a very good bond and good hydration. To a certain extent, it is absorbed less into the substrate, surface salting is limited and there is thus little evaporation.

(23) —A3— Surfactant

(24) The surfactants are preferably selected from: i. sources of anionic surfactants, such as for example, alkyl sulphates, alkyl ether sulphates, alkaryl sulphonates, alkyl succinates, alkyl sulpho-succinates, alkoyl sarcosinates, alkyl phosphates, alkyl ether phosphates, alkyl ether carboxylates, and alpha olefin sulphonates, preferably sodium lauryl sulphate, ii. non-ionic surfactants such as ethoxylated fatty alcohols, mono- or di-alkyl alkanolamides and alkyl polyglucosides, iii. amphoteric surfactants such as alkyl amine oxides, alkyl betaines, alkyl amidopropyl betaine, alkylsulphobetaines, alkyl glycinates, alkyl amphopropionates and alkyl amidopropylhydroxysultaines. iv. polyether polyols, hydrocarbon-containing molecules, silicone-containing molecules, hydrophobic esters, v. non-ionic surfactants, vi. polyoxiranes, vii. or mixtures thereof.

(25) By way of ionic surfactants, there may be mentioned non-limitatively alkyl ether sulphonates, hydroxyalkyl ether sulphonates, alpha olefin sulphonates, alkylbenzene sulphonates, alkyl ester sulphonates, alkyl ether sulphonates, hydroxyalkyl ether sulphates, alpha olefin sulphates, alkyl benzene sulphates, alkyl amide sulphates, as well as alkoxylated derivatives thereof (in particular ethoxylated (EO) and/or propoxylated (PO)), the corresponding salts or mixtures thereof. By way of ionic surfactants, there may also be mentioned non-limitatively saturated or unsaturated fatty acid salts and/or alkoxylated derivatives thereof, in particular (EO) and/or (PO) (such as for example sodium laurate, sodium palmitate or sodium stearate, sodium oleate), sulphonated methyl and/or sodium alpha laurates, alkyl glycerol sulphonates, sulphonated polycarboxylic acids, paraffin sulphonates, N-acyl-n-alkyltaurates, alkyl phosphates, alkyl succinamates, alkyl sulphosuccinates, sulphosuccinate monoesters or diesters, and alkyl glucoside sulphates. By way of ionic surfactants, there may be mentioned non-limitatively ethoxylated fatty alcohols, alkoxylated alkylphenols (particularly in particular (EO) and/or (PO)), aliphatic alcohols, more particularly, the products resulting from the condensation of ethylene oxide or propylene oxide with propylene glycol or ethylene glycol, the products resulting from the condensation of ethylene oxide or propylene oxide with ethylenediamine, alkoxylated fatty acid amides (in particular (EO) and/or (PO)), alkoxylated amines (in particular (OE) and/or (OP)), alkoxylated amidoamines (in particular (OE) and/or (OP)), amine oxides, alkoxylated terpene hydrocarbons (in particular (OE) and/or (OP)), alkyl polyglucosides, amphiphilic polymers or oligomers, ethoxylated alcohols, sorbitan esters or ethoxylated sorbitan esters. By way of amphoteric surfactants, there may be mentioned non-limitatively betaines, imidazoline derivatives, polypeptides or lipoamino acids. More particularly, the suitable betaines according to the invention can be selected from cocamido propyl betaine, dodecyl betaine, hexadecyl betaine, octadecyl betaine, phospholipids and derivatives thereof, amino acid esters, water-soluble proteins, esters of water-soluble proteins and mixtures thereof. By way of cationic surfactants, there may also be mentioned non-limitatively amino-laurate oxide, amino propyl cocoate oxide, caprylamphocarboxy glycinate, lauryl propionate, lauryl betaine, bis (2-hydroxyethyl) tallow betaine. According to a particular embodiment of the invention, the non-ionic foaming agent can be combined with at least one anionic or cationic or amphoteric foaming agent.

(26) By way of amphiphilic surfactants, there may be mentioned non-limitatively polymers, oligomers or copolymers that are at least miscible in aqueous phase. The amphiphilic polymers or oligomers can have a random distribution or a multiblock distribution. The amphiphilic polymers or oligomers used according to the invention are selected from block polymers containing at least one hydrophilic block and at least one hydrophobic block, the hydrophilic block being obtained from at least one non-ionic and/or anionic monomer. By way of example of such amphiphilic polymers or oligomers there may be mentioned in particular the polysaccharides having hydrophobic groups, in particular alkyl groups, polyethylene glycol and derivatives thereof. By way of amphiphilic polymers or oligomers, there may also be mentioned polyhydroxystearate—polyethylene glycol—polyhydroxystearate triblock polymers, acrylic polymers, branched or not, or the hydrophobic polyacrylamide polymers.

(27) With regard to non-ionic amphiphilic polymers, more particularly alkoxylated, (in particular (EO) and/or (PO)), the latter are more particularly selected from the polymers that are at least partially (at least 50% by weight) miscible in water. By way of example of polymers of this type, there may be mentioned inter alia, polyethylene glycol/polypropylene glycol/polyethylene glycol triblock polymers. Preferably, the foaming agent used according to the invention is a protein, in particular a protein of animal origin, more particularly keratin, or a protein of plant origin, more particularly a water-soluble wheat, rice, soya or cereal protein. By way of example, there may be mentioned sodium laurate of wheat protein hydrolysate, laurate of oat protein hydrolysate, or sodium cocoyl apple amino acids. Preferably, the foaming agent used according to the invention is a protein with a molecular weight of which is comprised from 300 to 50,000 Daltons. The foaming agent is used according to the invention at a ratio of 0.001 to 2, preferably 0.01 to 1, more preferably 0.005 to 0.2% by weight of foaming agent with respect to the weight of the binder.

(28) —A4— Secondary Binder

(29) In a preferred embodiment of the invention, the composition comprises at least one secondary binder —A4— different from the binder —A1— and selected from Portland cements, slags, geopolymer cements, natural pozzolans, sodium silicates, potassium silicates, lithium silicates, organic binders or mixtures thereof.

(30) For example, an artificial Portland cement suitable as the secondary binder A4 comprises 20% to 95% clinker containing: 50% to 80% C 3S; 4% to 40% C 2S; 0% to 20% C4AF; and 0% to 2% C 3A; 0% to 4% S; 0% to 80% blast furnace slag, silica fume, pozzolans and/or fly ashes.

(31) According to a variant, A4 is an organic binder selected from the group comprising—ideally constituted by—: redispersible polymer powders, epoxy (co)polymers, (co)polyurethanes, and mixtures thereof.

(32) According to a remarkable feature of the invention, the composition also comprises: —A5— a lubricating mineral filler with a particle size d90 less than 100 μm; —A6— a mineral spacing filler with a particle size d90 greater than or equal to 100 μm; and, optionally, one or more additives.

(33) —A5— Lubricating Mineral Filler

(34) The lubricating mineral filler with a particle size d90 less than 100 μm is preferably selected from natural and synthetic silica-containing minerals and even more preferably from clays, micas, kaolins and metakaolins, silica fumes, fly ashes and mixtures thereof, from calcareous or silica-calcareous fillers, from fly ashes, or from mixtures thereof.

(35) —A6— Spacing Mineral Filler

(36) The spacing mineral filler with a particle size d90 greater than or equal to 100 μm is preferably selected from siliceous, calcareous or silico-calcareous sands, light fillers, which are more particularly selected from vermiculite, expanded or not, perlite, expanded or not, glass beads, expanded or not, [hollow glass beads (3M® type) or expanded glass granules (Poraver®, Liaver®)], silica aerogels, polystyrene, expanded or not, cenospheres (fillites), hollow alumina beads, clays, expanded or not, pumices, silica-containing foam grains, rhyolite (Noblite®), or mixtures thereof.

(37) —A7— Water-Repellent Additive

(38) The waterproofing agent is preferably selected from the group comprising, or even better constituted by, agents containing fluorine, silane, silicone and siloxane, fatty acid metal salts and mixtures thereof, preferably from sodium, potassium and/or magnesium salts of oleic and/or stearic acid and mixtures thereof.

(39) —A8— Retarding Additive

(40) The retarder is preferably selected from the group comprising, or even better constituted by, calcium chelating agents, carboxylic acids and salts thereof, polysaccharides and derivatives thereof, phosphonates, lignosulphonates, phosphates, borates, and lead, zinc, copper, arsenic and antimony salts, and more particularly from tartaric acid and salts thereof, preferably the sodium or potassium salts thereof, citric acid and salts thereof, preferably the sodium salt thereof (trisodium citrate), sodium gluconates; sodium phosphonates; sulphates and the sodium or potassium salts thereof, and mixtures thereof.

(41) —A9— Accelerating Additive:

(42) The accelerator is preferably selected from the group comprising, or even better constituted by, alkali and alkaline earth salts of hydroxides, halides, nitrates, nitrites, carbonates, thiocyanates, sulphates, thiosulphates, perchlorates of silica, aluminium, and/or from carboxylic and hydrocarboxylic acids and salts thereof, alkanolamines, insoluble silica-containing compounds such as silica fumes, fly ashes or natural pozzolans, silica-containing quaternary ammoniums, finely divided mineral compounds such as silica gels or finely divided calcium and/or magnesium carbonates, and mixtures thereof; this additional accelerator preferably being selected from the group comprising, or even better constituted by, chlorides and the sodium or calcium salts thereof, carbonates and the sodium or lithium salts thereof, sulphates and the sodium or potassium salts thereof, calcium hydroxides and formates and mixtures thereof.

(43) —A10— Thickening Additive:

(44) A 10 is a different additive from A2, making it possible to improve the yield point of the mortar (slump resistance).

(45) Preferably, this thickening additive is selected from the group comprising, or even better constituted by, polysaccharides and derivatives thereof, polyvinyl alcohols, mineral thickeners, linear polyacrylamides and mixtures thereof.

(46) —Binder A Compositions:

(47) In an embodiment, the composition according to the invention is characterized in that the binder A comprises—in dry weight/weight % and in increasing order of preference—: —A1— primary binder: [5-95]; [10-85]; [15-75]; of which: lime: [10-95]; [20-70]; [30-60]; alumina source and/or calcium sulphate source: [0-90]; [5-30]; [7-15]; —A2— water-retaining agent: [0.1-5]; [0.5-3]; [0.8-2]; —A3— surfactant [0-2]; [0.01-1]; [0.05-0.5]; —A4— secondary binder [0-85]; [5-50]; [7-15]; —A5— lubricating mineral filler with a particle size d90 less than 100 μm: [0-40]; [0-30]; [0-20]; —A6— mineral spacing filler with a particle size d90 greater than or equal to 100 μm: [0-40]; [0-35]; [0-30]; —A7— water-repellent additive: [0-1.5]; [0-1]; [0-0.5]; —A8— retarding additive: [0-3]; [0-2]; [0-1]; —A9— accelerating additive: [0-3]; [0-2]; [0-1]; —A10— thickening additive: [0-2]; [0.1-1]; [0.2-0.8].

(48) In another embodiment, the composition according to the invention is characterized in that the binder A comprises—in dry weight/weight % and in increasing order of preference—: —A1— primary binder: [5-95]; [10-85]; [15-75]; of which: lime: [10-95]; [20-70]; [30-60]; alumina source and/or calcium sulphate source: [1-90]; [5-30]; [7-15]; —A2— water-retaining agent: [0.1-5]; [0.5-3]; [0.8-2]; —A3— surfactant: [0.01-1]; [0.05-0.5]; —A4— secondary binder [0-85]; [5-50]; [7-15]; —A5— lubricating mineral filler with a particle size d90 less than 100 μm: [0-40]; [0-30]; [0-20]; —A6— mineral spacing filler with a particle size d90 greater than or equal to 100 μm: [0-40]; [0-35]; [0-30]; —A7— water-repellent additive: [0-1.5]; [0-1]; [0-0.5]; —A8— retarding additive: [0-3]; [0-2]; [0-1]; —A9— accelerating additive: [0-3]; [0-2]; [0-1]; —A10— thickening additive: [0-2]; [0.1-1]; [0.2-0.8].

(49) —B— Biosourced Filler

(50) This biosourced filler typical of the compositions according to the invention is of animal or plant origin, preferably plant.

(51) When it is of plant origin, the filler —B— is essentially composed of cellulose, hemicellulose and/or lignin, said filler preferably comprising at least one component—fibres, fibrils, dusts, powders, chips, said component being: originating from at least a part of at least one plant raw material, in at least a particulate form, this plant raw material preferably being selected from the group comprising—or even better constituted by, hemp, flax, cereal straw, oat, rice, maize, canola seed, maize, sorghum, flax shives, miscanthus (elephant grass), rice, sugar cane, sunflower, kenaf, coconut, olive stones, bamboo, wood (e.g. wood pellets, for example spruce chippings), sisal, cork (beads) or mixtures thereof.

(52) By way of example of plant raw materials components, there may be mentioned: seed, stem, trunk, branch, leaf, flower, fruit, stone, stem, hull, husk, bark, bagasse, corn cob, etc.

(53) By way of example of particulate forms of plant raw material there may be mentioned: fibres, fibrils, dusts, powders, chips, hairs, shives, etc.

(54) These plant raw materials are natural, porous and rich in organic matter (celluloses, hemicelluloses, lignins, etc.). They are produced by industrial chipping, crushing, grinding and separation methods.

(55) The biosourced filler —B—, preferably of plant origin, is advantageously constituted by particles in various forms.

(56) According to the invention, a distinction is made between at least two categories of filler (B1, B2) depending on the particulate forms thereof: B1: acicular particles, comprising in particular: hemp, hemp chaff, flax, cereal straw, oat straw, rice straw, canola seed, maize stem husk, cotton, sorghum, flax shives, miscanthus, rice, sugar cane, sunflower, kenaf, coconut, olive stones, bamboo, wood (e.g. wood pellets, for example spruce chippings), sisal, B2: non-acicular particles, comprising in particular maize husk, cork pellets.

(57) To enhance the “pumpability” and homogeneity of the wet composition ready for application to a vertical or horizontal substrate or in formwork or a mould, it is beneficial for the particles of filler —B—, preferably of plant origin, to be non-acicular (B2), that is for example, granular and rounded.

(58) According to a variant, a filler of plant origin of the composition according to the invention comprises acicular particles of the hemp chaff, flax skives, etc. type.

(59) Intermediate Products

(60) A subject of the invention, as a new product, is also a partially biosourced binder —A— for construction materials, this binder being intended in particular for the composition according to the invention.

(61) Preferably, this binder A according to the invention comprises—in dry weight/weight % and in increasing order of preference—: —A1— primary binder: [5-95]; [10-85]; [15-75]; of which: lime: [10-95]; [20-70]; [30-60]; alumina source and/or calcium sulphate source: [0-90]; [5-30]; [7-15]; —A2— water-retaining agent: [0.1-5]; [0.5-3]; [0.8-2]; —A3— surfactant: [0.01-1]; [0.05-0.5]; —A4— secondary binder [0-85]; [5-50]; [7-15]; —A5— lubricating mineral filler with a particle size d90 less than 100 μm: [0-40]; [0-30]; [0-20]; —A6— mineral spacing filler with a particle size d90 greater than or equal to 100 μm: [0-40]; [0-35]; [0-30]; —A7— water-repellent additive: [0-1.5]; [0-1]; [0-0.5]; —A8— retarding additive: [0-3]; [0-2]; [0-1]; —A9— accelerating additive: [0-3]; [0-2]; [0-1]; —A10— thickening additive: [0-2]; [0.1-1]; [0.2-0.8].

(62) By way of new product, the invention also relates to a kit containing the aforementioned binder —A— and the plant filler —B— as defined above.

(63) Wet Composition

(64) According to another aspect thereof, the invention relates to a wet construction composition formed by a mixture of the dry composition according to the invention, mixed with a liquid, preferably water.

(65) According to a remarkable feature of the invention, this wet composition is pumpable in a screw pump with an air gap (E) between the rotor (20) and the stator (18) comprised between 4 and 30 mm. The reference signs refer to the single FIGURE attached. Such an air gap preferably corresponds to a commercially available jacket of the 2L6 or 2R6 type.

(66) Method for Preparing the Wet Composition

(67) The present invention also relates to a method for preparing the wet composition as defined above. This method consists of mixing a liquid, preferably water, with the dry construction compound as defined above, advantageously in a weight ratio [water/Binder —A—] greater than or equal to 0.8, preferably greater than 1, preferably greater than 1.5.

(68) This mixture can be made by any appropriate conventional device known to a person skilled in the art.

(69) This can be a planetary mixer or fixed auger (vertical or horizontal) mixer or a concrete mixer. The mixing device may or may not be installed directly on the machine comprising the screw pump and used to apply the wet composition by spraying or pouring.

(70) Machine for Pumping and Spraying the Aforementioned Wet Construction Composition

(71) The machines under consideration herein are “screw pumps”, preferably: of the type used for spraying façade render (such as Lancy PHB-R, Bunker S8 Smart, Urban Volta, Spritz S28R, Spritz S38, Turbosol UNI30, Putzmeister SP11, S5 or SP5); or concrete pumps (of the Bunker B100 type).

(72) Patent application WO97/45461A1 describes an example of this type of “screw pump”. The latter generally comprises a suction chamber and a discharge port arranged respectively at each end of a stator, inside which is arranged a single-helix helical rotor suitable for working with a double-helix stator. The stator is preferably constituted by an elastomer material, while the rotor 18 is advantageously made from metal. The latter is rotatably mobile about its axis via appropriate drive and transmission means. U.S. Pat. Nos. 2,512,764 and 2,612,845 are examples, inter alia, of sources of information on the detailed structure of these screw pumps.

(73) The attached single FIGURE shows a simplified diagram of a screw pump comprising a stator tube 16, a stator 20 with a through-bore 36 in which a rotor 18 is rotatably mobile. This stator tube 16/stator 20 has a suction end 32 and a discharge end or discharge port 34. When the rotor 18 rotates inside the bore 36 of the stator 20, cavities 30 are formed between the rotor 18 and the stator 20. These cavities 30 progress from the suction end 32 to the discharge end or port 34. The cavities 30 have a length defined by the pitch of the helix of the rotor 18 and by a maximum height or air gap E shown in the single FIGURE. This air gap E can for example vary between 1 and 50 mm, preferably 4 to 30 mm.

(74) This stator tube 16/stator 20/rotor 18 assembly is also known as a jacket.

(75) The jackets/stators commonly mounted on façade render spraying machines are, for example, of the “2L6” or 2R6 type or the 2R8 type (compatible with the Bunker B100 concrete pump).

(76) Method for Applying this Wet Composition

(77) The present invention also relates to a method for applying the wet composition as defined above (steps 1, 2 and 3 {3.1, 3.2 or 3.3}):

(78) Preferably, the wet mortar is applied by spraying by means of a machine called a “renderer's” spraying machine, comprising a screw pump. For a biosourced filler —B— smaller than 10 mm, the spraying machine is advantageously a machine of the Putzmeister S5, SP5, SP11, Bunker S8, S28R, S38, Lancy PH9B or PH9B-R, or Turbosol Talent DMR type, this machine comprising a screw pump fitted with a 2L6 or 2R6 type rotor-stator. For a biosourced filler —B— larger than or equal to 10 mm and smaller than 30 mm, the spraying machine is advantageously a machine of the Bunker B100 and CL18, Putzmeister SP20, Lancy TB20, or Turbosol Silant 300 CL type, this machine comprising a screw pump fitted with a 2L8 or 2R8 type rotor-stator.

(79) 1. Preparing a Mixture of Liquid—Preferably Water—, and the Dry Composition According to the Invention.

(80) The mortar is mixed in the drum of the machine when it has one, or in a concrete mixer, as described below, preferably: —a— Mixing 100 L of the biosourced filler —B— with the mixing water (all of the water minus approximately 2 L) for at least one minute. —b— Introducing all of the binder and then mixing for approximately five minutes, adjusting the viscosity by adding water, if required. The mortar viscosity obtained must enable good flow into the pumping tank (mortar settling horizontally under its own weight) while maintaining a threshold enabling 5 cm slump resistance. —c— Transferring the mixture to the tank of the screw pump.

(81) 2. Pumping the Mixture Prepared in Step 1 by Means of a Screw Pump

(82) So-called “renderer's” spraying machines generally comprise a hose for pumping the wet mortar formulation, upstream of the screw pump, and downstream of it, a spray hose the free end of which is fitted with a spray gun.

(83) Preferably, before the screw pump is started, a slurry of the binder (e.g. between 1 and 50 kg, approximately 10 kg) is preferably introduced into the pumping hose in order to “grease” and “lubricate” said hose.

(84) The screw pump is preferably set beforehand, using water, to a pressure for example from 1 to 20 bar: approximately 5 bar for a 2L6 jacket or from 1 to 20 bar: approximately 3 bar for a 2L8 jacket.

(85) For a 2L6 or 2R6 jacket, the spray hose comprises for example a first portion with an inner cross-section of, for example, 15 to 50 mm, 35 mm, over a length of for example 5 to 30 m, approximately 13 m, and a second portion with an inner cross-section of, for example 15 to 50 mm, 25 mm, and a length of, for example, 1 to 10 m, 5 m.

(86) For a 2L8 or 2R8 jacket, the spray hose has for example an inner cross-section of 50 mm over a length of 10 m.

(87) 3. Spraying the Mixture Prepared in Step 1

(88) For spraying, the spray gun is advantageously supplied with compressed air.

(89) Hardened Mortars

(90) The invention relates to hardened mortars obtained from the aforementioned wet composition. These hardened mortars advantageously have a thermal conductivity λ (lambda) less than or equal to—in W/m.Math.K and in increasing order of preference—0.15; 0.12; 0.1; 0.08; 0.07.

(91) ETI/ITI Systems

(92) The invention relates to an External Thermal Insulation (ETI) or Internal Thermal Insulation (ITI) system comprising hardened mortar as set out above and applied in layer(s) over a total thickness comprised between 2 and 30 cm, preferably between 5 and 15 cm, and coated with a waterproof render at least 10 mm thick. This system is characterized in that the hardened mortar comprises lime and at least one alumina source and in that it meets the test for ETI in accordance with EOTA standard ETAG 004.

(93) The waterproof render advantageously complies with NF EN 998-1. It is preferably selected from OC1 types of render. It is for example applied after a minimum of 24 hours following the application of the last pass of biosourced insulating mortar.

(94) Building or Civil Engineering Structures

(95) The invention also relates to building structures obtained after application by spraying or moulding or by on-site assembly of items prefabricated using the composition according to the invention.

(96) Further details and advantageous features of the invention will become apparent below from the description of embodiments of the invention.

EXAMPLES

(97) Pumpability Test T1:

(98) Test T1 consists of carrying out a test passage of a wet formulation obtained using the mortar composition for testing, through a renderer's spraying machine fitted with a screw pump. For a category B2 biosourced filler, or smaller than or equal to 10 mm, a screw pump fitted with a 2L6 type rotor-stator mounted on a machine of the Putzmeister SP11 type is used, For a category B1 biosourced filler, larger than 10 mm and smaller than 30 mm, a screw pump fitted with a 2L8 rotor-stator mounted on a Bunker B100 machine, with integral mixer, is used.

(99) The mortar is mixed in the machine drum as follows: 1. Mixing 100 L of biosourced filler —B— with almost all of the mixing water for one minute, with a water to A ratio comprised between 0.8 and 5. 2. Introducing all of the binder —A— and then mixing for five minutes, adjusting the viscosity by adding a small quantity of water if required, so that the viscosity of the mortar obtained enables it to flow into the pumping tank of the screw pump in less than one minute. 3. Transferring the mixture to the tank of the screw pump. 4. Adjusting the screw pump beforehand by tightening, while passing water into the jacket, to obtain a pressure at the jacket outlet of approximately 5 bar for a 2L6 jacket or approximately 3 bar for a 2L8 jacket. 5. Pumping the mixture present in the tank of the screw pump.

(100) The composition for testing is considered to be pumpable if the screw pump does not become blocked, that is, it is observed that the wet mortar formulation is not expelled at the screw pump outlet or phase separation is observed between the biosourced filler —B— and the binder phase, at the screw pump outlet.

(101) By “not expelled” is meant wet formulation is output for at least 30 minutes, in a quantity less than one litre.

(102) By “phase separation” is meant the separation between the interstitial liquid and the granular phase of the mortar. The jamming or clogging of the pump is a consequence of the separation between the liquid phase and the granular network when the product is passed through a confined space. This phase separation will result in the occurrence of direct contact between aggregates (in particular the particles of filler —B—), hence the blockage.

(103) This test is carried out at ambient temperature and pressure.

(104) Measurement Method M1 Giving the “Hardening” Time of a Biosourced Mortar and making it Possible to Estimate the Recoat Time

(105) The recoat time is linked to the hardening of the biosourced mortar. The hardening time corresponds to the acquisition of compressive strength (NF EN 1015-11) greater than or equal to 0.1 MPa, enabling the removal from the mould of a 4×4×16 cm test piece.

(106) Protocol:

(107) 1. The product is mixed using a planetary mixer with a vertical auger as specified in NF EN 196-1. a) The plant filler B is mixed with almost all of the mixing water for one minute, at a speed of 120 rpm, with a water to A ratio comprised between 0.8 and 5. b) The binder is added and then mixed for 300 seconds at a speed of 120 rpm. The viscosity is adjusted by adding a small quantity of water, if required, so that the mixed mortar can flow into a mould in step 2 in less than 30 seconds.

(108) 2. After mixing, the mortar is poured into metal moulds measuring 4×4×16 cm.

(109) 3. The test pieces are then stored at 20° C. and 50% RH.

(110) 4. The “hardening” time corresponds to the moment when the cohesion of the test piece enables it to be removed from the mould without damage.

(111) By “damage” is meant cracking and/or partial or total failure of the test piece.

(112) Measurement Method M2 Measurement of the Water Retention Time of a Biosourced Mortar

(113) This method M2 corresponds to an adaptation of the method known as filter method.

(114) Apparatus:

(115) Metal mould. Inner dimensions: Top diameter: 100 30 5 mm. Bottom diameter: 80+/−5 mm. Height: 25+1 mm. Outer dimensions: Diameter: 120+/−5 mm. Height: 30+1 mm. Spatula Glazed tile (size: approximately 120 mm×5 mm) Balance accurate to 0.01 g 100 mm diameter filter paper (Schleicher or filtre-Lab 0965 NW 25 L): separating filter. (i). 100 mm diameter filter paper (Schleicher 2294 or filtre-Lab S-Type 600)
Protocol:

(116) 1. The sample is prepared according to the mixing method described in test T2.

(117) 2. Weigh the empty, dry mouldm.sub.A.

(118) 3. Weigh the Schleicher 2294 or filtre-Lab S-Type 600 filter paperm.sub.B.

(119) 4. Fill the mould with the hemp mortar using a spatula. Overfill slightly to ensure contact between the filter and the paste.

(120) 5. Weigh the filled mouldm.sub.C.

(121) 6. Cover the paste with the separating filter paper (Schleicher or filtre-Lab 0965 NW 25 L) and then place the 2294 or S-600 filter on the assembly.

(122) 7. Place the glazed tile on the assembly, turn the assembly upside down and start the timer. The test duration is 15 minutes.

(123) 8. After 15 minutes, retrieve the 2294 or S-600 filter paper and weigh itm.sub.D.

(124) Expression of Results:

(125) Calculation 1: mass of water contained in the product
Mwater=((m.sub.C−m.sub.A)*Tg %)/(100+Tg %)

(126) Calculation 2: water loss from the product
Δwater=(m.sub.D−m.sub.B)

(127) Calculation 3: Water retention as a %
R %=((Mwater−Δwater)/Mwater)*100
EN 1015-8: Methods of test for mortar masonry—Part 8: Determination of water retentivity of fresh mortar. (September 1999)

(128) Raw Materials

(129) Binder A

(130) A1:

(131) HYDRAULIC LIME HL 3.5, LAFARGE

(132) SULPHOALUMINATE CEMENT, I.TECH ALI CEM, ITALCEMENTI;

(133) A2:

(134) CULMINAL C8367, WATER-RETAINING AGENT, METHYL HYDROXYETHYL CELLULOSE, VISCOSITY 32,000-40,000 MPA.Math.S, ASHLAND AQUALON;

(135) A3:

(136) NANSA LSS 495/H, SURFACTANT, SODIUM ALPHA OLEFIN SULFONATE, HUNTSMAN;

(137) A5:

(138) SILICA FUME, RW SILICIUM GMBH;

(139) A6: PORAVER, EXPANDED GLASS GRANULES, GRANULE SIZE IN MM 01-03, PORAVER GMBH; SILICEOUS SAND, 0.1/0.4 SIBELCO FRANCE

(140) A7:

(141) OPTIGEL WM, ORGANICALLY MODIFIED BENTONITE, ROCKWOOD ADDITIVES.

(142) FILLER —B—:

(143) “KANABAT” hemp chaff for building: Category B1 particulate form, particle size variable between 10 and 30 mm.

Comparative Example 1

(144) Formula according to the prior art (for example Tradical® PF70).

(145) Tradical PF70, produced by Balthazard et Cotte Batiment (Lhoist group) comprises approximately 75% hydraulic lime, 15% hydraulic binder and 10% pozzolanic material.

(146) The conclusions of the test according to method T1 are: Blockage of the machine due to phase separation. Retention according to T3 is less than 90%: Hardening time greater than 48 hrs measured according to T2.

(147) TABLE-US-00001 COMPARATIVE EXAMPLE 1 Spraying machine BUNKER B100 Jacket used 2L8 Description of formula Prior art TRADICAL PF70 Binder matrix [kg] 33 B. Filler labelled KANABAT “hemp chaff for building”: Volume [L] 100 Weight [kg] 10 Filler B/Binder A volume/weight ratio [L/kg] 3.03 Filler B/Binder A weight/weight ratio [kg/kg] 0.3 Water [L] 42 Water/Binder A weight ratio 1.27 Binder matrix composition A Binder TRADICAL PF70 100% (BCB) Application observations Passage through machine/pumping during test T1 Pump blockage/phase separation Properties in hardened state Density [kg/m.sup.3] — Thermal conductivity [W/m .Math. K] —

Examples 2, 3, 4

(148) In these examples, the dry hemp mortar compositions have the same filler B/binder A ratio [L/kg]. They are applied with a spraying machine fitted with screw pump (BUNKER B100) using a 2L8 jacket. All of the compositions are pumpable according to T1.

(149) TABLE-US-00002 EXAMPLES 2 3 4 Spraying machine BUNKER BUNKER BUNKER B100 B100 B100 Jacket used 2L8 2L8 2LB Description of formula Without With With spacing spacing spacing mineral mineral mineral fillers fillers fillers Binder matrix [kg] 25 25 25 B. Filler labelled KANABAT 100 100 100 “hemp chaff for building”: 10 10 10 Volume [L] Weight [kg] Filler B/Binder A volume/weight 4 4 4 ratio [L/kg] Filler B/Binder A weight/weight 0.4 0.4 0.4 ratio [kg/kg] Water [L] 38 38 34 Water/Binder weight ratio 1.52 1.52 1.36 Binder matrix composition A.1 Main Hydraulic Lime   80% 87.88% 67.88% mineral binder HL 3.5 (Lafarge) A.2 Water- MHEC  1.5%  1.13%  1.13% retaining agent CULMINAL C8367 (Ashland) A.3 Surfactant NANSA LSS 0.09%  0.09%  0.09% 495/H (Huntsman) A.10 OPTIGEL WM 0.90%  0.90%  0.90% Thickening (Tolsa) Additive A.6 Spacing PORAVER  7.89% mineral filler 01-03   20% Siliccous Sand DU 01-04 A.5 SILICA FUME   10%   10%   10% Lubricating mineral filler Application observations Passage through machine/ Passage Passage Passage pumping during test T1 through through through machine machine machine satisfactory satisfactory satisfactory Properties in hardened state Density [kg/m.sup.3] — 400 — Thermal conductivity [W/m .Math. K] — 0.08 —

Examples 5 and 6

(150) Examples of hemp mortar-based insulation systems subjected to ageing tests in accordance with the EOTA external thermal insulation standard, ETAG 004 for external thermal insulation. The insulation systems are composed of 10 cm of hemp mortar and a water-resistant lime finishing render (PAREXAL-PAREXGROUP SA). The hemp mortars have the same Filler B/Binder A ratios (100 L/25 kg) but differ in the formula of the binder

(151) A.

(152) The formula in example 6 differs from the formula in example 5 solely through the presence of 10% sulphoaluminate cement (i.tech ALI CEM).

(153) With the addition of a sulphoaluminate cement, the insulation system in example 6 successfully withstood the ageing cycles described in ETAG 004 for ETI systems. The recoat time between two passes of hemp-based insulating mortar is 24 hrs-48 hrs depending on the weather conditions, instead of 3-7 days for the formula in example 5 without sulphoaluminate cement.

(154) Recoatability corresponds to the possibility of applying a fresh coat onto an initial coat that is touch-dry, so that it withstands the deformation caused by the application of this fresh coat.

(155) TABLE-US-00003 6 EXAMPLES 5 Preferred example Spraying machine BUNKER B100 BUNKER B100 Jacket used 2L8 2L8 Description of formula Without CSA With CSA cement cement Binder A [kg] 25 25 B. Filler labelled KANABAT 100 100 “hemp chaff for building”: 10 10 Volume [L] Weight [kg] Filler B/Binder A volume/ 4 4 weight ratio [L/kg] Filler B/Binder A weight/ 0.4 0.4 weight ratio [kg/kg] Water [L] 38 36 Water/Binder A weight ratio 1.52 1.44 Binder A composition A1. Main Hydraulic Lime 68.78% 58.78% mineral binder HL 3.5 (Lafarge) Sulphoaluminate   10% cement, i.tech ALI CEM (Italcementi) A2. Water- MHEC  1.13%  1.13% retaining agent CULMINAL C8367 (Ashland) A3. Surfactant NANSA  0.09%  0.09% LSS 495/H (Huntsman) A6. Spacing Siliceous sand   20%   20% mineral filler DU 0.1-0.4 A5. Lubricating SILICA FUME   10%   10% mineral filler Test wall applied in accordance with ETAG 004 Thickness of hemp chaff- 10 cm 10 cm based insulating mortar Scratch finish lime render  1 cm  1 cm (PAREXAL- PAREXGROUP SA) Recoat time between passes 3-7 days 1-2 days of hemp mortar Performance after ageing cycles in accordance with ETAG 004 Cracks Cracks appeared No cracks before and during appeared the ageing cycles. after the cycles The cracks passed through the finishing render to the insulating mortar. Bond [N/mm2] 0.026 0.22 Approval of the insulation System not System system in accordance with approved: approved ETAG 004 “structural” cracks (hemp mortar and finish) Passage through machine/ Passage through Passage through pumping during test T1 machine machine satisfactory satisfactory

Examples 7, 8, 9

(156) These examples show the impact of the B/A (filler/binder) ratio on the thermal conductivity of the sprayed hemp chaff-based insulating mortar. The compositions in examples 7, 8 and 9 give wet formulations that are pumpable in accordance with test T1 and have respective B/A ratios of 4, 3.3 and 2.6.

(157) The compositions in examples 7, 8 and 9 have a hardening time measured in accordance with method M1 of less than 24 hours.

(158) The composition in example 7 gives a lambda value<0.1 W/(m.Math.K).

(159) The reduction in the B/A ratio results in an increase in the thermal conductivity measured using a guarded hot plate (ambient T: 20° C., RH: 50%). For a hemp chaff-based mortar, the thermal conductivity is less than 0.1 W/m.Math.K, if the B/A ratio (hemp chaff B/binder A) is greater than 3.33.

(160) TABLE-US-00004 EXAMPLES 7 8 9 Spraying machine BUNKER B100 BUNKER B100 BUNKER B100 Jacket used 2L8 2L8 2L8 Binder A [kg] 25 30 37.5 B. Filler labelled KANABAT “hemp chaff for building”: Volume [L] 100 100 100 Weight [kg] 10 10 10 Filler B/Binder A volume/weight 4 3.33 2.6 ratio [L/kg] Filler B/Binder A weight/weight 0.4 0.33 0.27 ratio [kg/kg] Water [L] 36 36 38 Water/Binder A weight ratio 1.44 1.2 1.01 Binder matrix composition A.1 Main Hydraulic Lime HL 58.78% 69.10% 89.51% mineral binder 3.5 (Lafarge) Sulphoaluminate 10% 10% 10% cement, i.tech ALI CEM (Italcementi) A.2 Water- MHEC CULMINAL 1.13% 0.80% 0.40% retaining agent C8367 (Ashland) A.3 Surfactant NANSA LSS 495/H 0.09% 0.10% 0.09% (Huntsman) A6. Spacing Siliceous Sand DU 20% 20% mineral filler 01-04 A5. Lubricating SILICA FUME 10% mineral filler Application observations Passage through machine/pumping Passage through Passage through Passage through during test T1 machine machine machine satisfactory satisfactory satisfactory Properties in hardened state Density [kg/m.sup.3] 458 559 671 Thermal conductivity [W/m.K]: 0.074 0.100 0.114 measured using the hot plate method.