FR3004711A1 - AGGLOMERATED PLANT FIBER BLOCK COMRESS. - Google Patents

Abstract

The present invention relates to compressed agglomerated vegetable fiber blocks, comprising particles of plant fibers, a hydraulic binder called blast furnace slag and a hydraulic binder called cement, their uses, in particular for making constructions and a process for the manufacture of these blocks.

Description

The present invention relates to compressed agglomerated vegetable fiber blocks, their uses, in particular for producing constructions, as well as a method of manufacturing these blocks. The production of agglomerated blocks of wood is written in the document WO 2006/120353 A2. This application describes a process in which an initial mixture comprising wood particles and a hydraulic binder is maintained in a pressurized mold throughout the setting time of the binder. The blocks thus obtained have good strength and can be used in the field of construction. The present application proposes an alternative to the blocks described in the prior art. It stems in particular from the demonstration that agglomerated and resistant blocks can be produced from vegetable fibers in fine particles, and by mixing a hydraulic binder derived from blast furnace waste commonly called blast furnace slag with another hydraulic binder called commonly cement. The present application with respect to the blocks described in the prior art makes it possible to reduce by 20% to 70% the quantity of the hydraulic binder called cement, which has a high cost financially in raw material prices, which has a very negative carbon balance with a significant CO2 discharge, and which has disadvantages compared to the hydraulic binder called blast furnace slag as explained later. It also shows that such blocks are perfectly suited for use in the field of construction. The invention thus proposes a solution to the treatment of many wastes or raw material based on plant fibers, as well as blast furnace waste commonly known as blast furnace slag, and allows the production of agglomerated blocks having greater strength qualities, Unexpected density, low thermal conductivity (0.12 VV / mK), better impermeability to water, avoid frost and thaw effects, avoid sulphate and chloride ion attack , to avoid attacks by seawater or acidic water, to reduce the release of CO2 in the atmosphere by the use of the hydraulic binder called blast furnace slag, to store CO2 with the use of plant fibers, to have a lighter color, to make an economical product thanks to the use of waste in majority and by decreasing significantly the hydraulic binder called cement, compatible with the 10 sheave the use of load-bearing elements for construction or roofing elements in tile-like construction or the like. The blocks of the invention through the use of the mixture of hydraulic binder components called blast furnace slag and hydraulic cement binder, preferably have a reinforced water impermeability, higher strength qualities, avoidance the effects of freezing and thawing, to avoid attacks of sulphates and chloride ions, to avoid attacks by seawater or acidic water, to reduce the release of CO2 into the atmosphere through the use of hydraulic binder called blast furnace slag, to have a lighter color, and to make an economic product 20 through the use of waste and the significant decrease in the amount of hydraulic binder called cement which is an expensive material, compared the agglomerated wood blocks listed in WO 2006/120353 A2. The present invention thus provides, for the first time, blocks of compressed agglomerated vegetable fibers comprising a high proportion of fine particulate plant fibers and having certain characteristics close to that of the raw plant used. An object of the invention thus resides in a block of compressed agglomerated vegetable fibers comprising vegetable fibers of fine particles, a hydraulic binder called blast furnace slag and a hydraulic binder called cement, and advantageously having a high density. The blocks of the invention are advantageously obtained by a process in which an initial mixture comprising fine particulate plant fibers, a hydraulic binder called blast furnace slag and a hydraulic binder called cement is kept under pressure for the duration of setting hydraulic binders. The blocks of the invention have excellent mechanical properties, especially in terms of resistance to compression, water and fire, the attack of sulphates and chloride ions, to avoid freezing and thawing effects, and are quite suitable for use as a building element. These blocks are particularly advantageous with respect to existing materials, such as concrete, in particular because of their reduced weight, their better thermal insulation capacity (low thermal conductivity 0.12 W / mK), their better impermeability to water, their lighter color, their greater ecological value, and their economically low cost thanks to the use of waste and the significant reduction of the hydraulic binder called cement which is an expensive material, making it possible to realize load-bearing members for building or roofing element for tile-like construction or the like. A particular object of the invention thus resides in a block of compressed agglomerated vegetable fibers, characterized in that it comprises vegetable fibers in fine particles, a hydraulic binder called blast-furnace slag and a hydraulic binder called cement and in that it is obtained by a process in which an initial mixture comprising fine-particulate plant fibers, a hydraulic binder called blast-furnace slag and a hydraulic binder called cement is kept under pressure for the duration of binding of binders, the fibers The present invention is characterized in that it contains at least 65%, preferably from 65% to 95%, of the total volume of the dry matter of the initial mixture. Another subject of the invention relates to a block of compressed agglomerated vegetable fibers, characterized in that it comprises vegetable fibers in fine particles, a hydraulic binder called blast furnace slag and a hydraulic binder called cement, in that it is obtained by compression of an initial mixture comprising at least 65% of vegetable fibers in fine particles, by volume of dry matter, and in that it has a density greater than 400 kg / m 3. The blocks of the invention through the use of the mixture of the hydraulic binder component called blast furnace slag and the cement hydraulic binder component, preferably have a reinforced water impermeability, higher strength qualities, higher resistance to water, and a higher water resistance. avoid freeze and thaw effects, avoid sulphate and chloride ion attacks, avoid attacks by seawater or acidic water, reduce the release of CO2 into the atmosphere by the use of the hydraulic binder called blast furnace slag, to have a lighter color, and to make an economic product through the use of waste and the significant reduction of the hydraulic binder called cement which is an expensive raw material, as compared to the agglomerated wood blocks listed in WO 2006/120353 A2. The blocks of the invention preferably have a density greater than 400 kg / m3. Furthermore, the blocks of the invention are preferably prepared from a mixture comprising at least 65%, by volume of dry matter, vegetable fibers in fine particles, preferably from 65% to 95%, typically from 75 to 95%. In addition, the blocks of the invention advantageously have a puncture compression strength greater than 0.5 mPa, typically exceeding 3 mPa, for a block of 5 cm 3. In addition, the blocks of the invention advantageously have a thermal conductivity of 0.12 W / mK which makes it possible to have good thermal insulation whether for the walls or whether for a blanket of building. Preferably, the compressed agglomerated vegetable fiber blocks are produced from a mixture comprising, for a total of 100% representing the volume of the dry matter, from about 65% to about 95% of fine particulate plant fibers and about 35% of hydraulic binders referred to as blast furnace slag and called cement, and 10% to 30% of the total volume of dry matter. Preferably, the mixture of hydraulic binders is composed of 20% to 70% of hydraulic binder called blast furnace slag and 30% to 80% of hydraulic binder called cement according to the requirements of mechanical strength or impermeability required. The plant fibers used may be based on wood fibers, bamboo fiber, reed fiber, palm leaf stalk fiber, tree leaves, shrub fiber, apple fiber pine, pine needle, straw, flax fiber, hemp fiber, cellulose fibers obtained after preferably chopping, or grinding, or shredding into fine particles and drying or any other quality of vegetable fibers . Vegetable fibers made of fine particles can be used in a mixture with each other. The hydraulic binders used are blast furnace slag and cement. In this respect, it is possible to use any type of high-blast slag. In this respect, it is possible to use any type of cement available commercially, such as standard cements but more particularly a cement of 42.5 cpd. Preferably and in a preferred embodiment of the invention, the blocks have for a mixture of hydraulic binders of 100% a distribution of 45% to 50% of hydraulic binder called blast furnace slag and 50% to 55% of binder hydraulic system called cement, which reduces by half the negative impact of the hydraulic binder called cement which generates an expensive raw material, a release of CO2 in the atmosphere, a dark color, a weak impermeability, effects with the gel and thawing, sulphate and chloride attack, attack by seawater or acidic water and less resistance. In a preferred embodiment of the invention, the plant fibers comprise fine-particle vegetable fibers derived from wood fibers, optionally mixed with other fine-particulate plant fibers in order to increase certain properties such as the mechanical resistance to the compression. It may be in particular fine-particle vegetable fibers obtained, for example by preferably chopping, or grinding, or shredding and drying. Advantageously, the plant fibers come from wood fibers which are preferably minced, or crushed, or shredded into fine particles and then dried. Naturally, mixtures of plant fibers with fine particles can be used from the recycling of waste or crops. In a particular embodiment, plant fibers are used in chopped, milled or shredded fine fibers and dried in order to obtain a homogeneous mixture, with the hydraulic binder called blast furnace slag mixed with the hydraulic binder called cement and thus allow better mechanical endurance, better water impermeability, better resistance to freeze-thaw effects, better resistance to sulphate and chloride ion attack, better resistance to attack by water seawater and acidic water, better lighter color, a more economical product through the use of waste with vegetable fiber and the hydraulic binder called blast furnace slag, a decrease in CO2 release in the atmosphere through the use of waste with vegetable fiber and hydraulic binder called blast furnace slag, a better 3004 7 1 1 carbon footprint by CO2 storage with the use of plant fiber and low thermal conductivity (0.12 W / mK) to produce load bearing elements for construction and cover elements for type construction tile or other. In a particular embodiment, a proportion of plant fibers may be composed of plant fibers other than wood fiber. Thus, in particular blocks according to the invention, the volume of the fine-particle wood fibers is reduced between 5% and 25% and compensated by the same percentage by the addition of other vegetable fibers in order to allow other properties or reinforced such as impermeability, thermal resistance, mechanical resistance or CO2 storage. Thus, in a particular embodiment, the blocks of compressed agglomerated vegetable fibers are produced from a mixture comprising, for a total of 100% representing the volume of the dry matter, from 40% to 90% of vegetable fibers of fine particles, from 5% to 25% of cellulose fiber and from 5% to 35% of hydraulic binders referred to as blast furnace slag and called cement, and a quantity of water of between 10% and 30% of the volume total dry matter. Cellulose fiber is particularly used because it can be recovered with old paper and thus be very economical as a supplemental raw material. In a particular embodiment, the block also contains one or more adjuvants, making it possible to adapt or improve the properties of the blocks. Mention may in particular be made of adjuvants for coloring, accelerating or delaying the binding of binders, water repellency, fireproofing, fungicidal or insecticidal treatment, fluidification of the mixture, faster curing, high mechanical strength. performance, reinforcing fibers of the agglomerated block or a mineral filler. Any adjuvant usable in the concrete can be used in the present invention. In a particular embodiment, the block may have on the weather-exposed face in the case of a roofing element for the construction a surface coating by application of paint or material (bituminous slate, clay powder, resin, etc.) to obtain a color (slate, tile, etc.) and additional impermeability protection. The blocks of the invention can have a varied shape and thickness, depending on the desired use (load-bearing wall, panel, floor, roof, beam, fence, street furniture or habitat, tile-like roofing element or the like, etc.). ). In a particular embodiment, the block comprises reliefs to allow interlocking between blocks and thus to ensure a seal in the case of a realization of a wall or a building cover. The block may also have a hooking relief in order to be fixed on a blanket-type support. The block can be fixed by nailing or screwed onto the support. An essential advantage of the compressed sintered block according to the invention is that it contains a high proportion of vegetable fibers in fine particles, thanks to the maintenance of the pressure, which makes it possible to obtain a dense material with relatively few binders. It thus presents insulation qualities close to those of the plant fiber used initially, as well as a good mechanical resistance, as well as a good CO2 storage, and thus a better impermeability to water which makes it suitable for the construction of supporting structures or roofing elements used for buildings. Another object of the invention resides in a process for preparing a compressed agglomerated block as defined above. In one particular embodiment, the process for preparing a compressed agglomerated vegetable fiber block comprises the steps of forming or pouring into a mold a mixture comprising fine particulate plant fibers, a hydraulic binder, and the like. called high-blast slag and a hydraulic binder called cement, moistened with water, and then applying and maintaining the mixture under pressure for the duration of the hydraulic binders. Another particular object of the invention thus resides in a block of compressed agglomerated vegetable fibers, comprising vegetable fibers of fine particles, a hydraulic binder called blast furnace slag and a hydraulic binder called cement, obtained by a process in which a initial dry and homogenous mixture comprising first dry blending the hydraulic binders called blast furnace slag and called cement, then the vegetable fibers in fine particles, then moistened with water, is poured into a mold and kept under pressure for the entire duration of setting hydraulic binders. Preferably, the initial mixture comprises, for a total of 100% representing the volume of dry matter, from 65% to 95% fine vegetable vegetable fibers, from 5% to 35% hydraulic binders, and an amount of water between 10% and 30% water of the total volume of dry matter. Preferably, the initial mixture of hydraulic binders is composed of 20% to 70% of hydraulic binder called blast furnace slag and 30% to 80% of hydraulic binder called cement. In a particular embodiment, the mixture as indicated above may contain one or more adjuvants chosen for example from adjuvants for coloring, acceleration or retardation of binding of the binder, water repellency, fireproofing. , the fungicidal or insecticidal treatment, the fluidification of the mixture, a faster hardening, a high performance mechanical resistance, reinforcing fibers of the agglomerated block or a mineral filler. In addition, as indicated above, the block may have on the weather-exposed side in the case of a cover element a surface coating by application of paint or material (bituminous slate, clay powder, resin, etc.) so to obtain a color (slate, tile, etc.) and a complementary protection of impermeability. The pressure applied to the mixture may be adapted by those skilled in the art, depending on the properties and the desired use. In a particular variant embodiment, it is less than 1 MPa, preferably less than 0.8 MPa, and can be for example 0.1 MPa. An advantage of the invention is that this method is simple to implement, requiring no complex physical or chemical treatment that would increase the costs, the time of implementation. Mixing the ingredients dry, firstly the hydraulic binders between them and then the vegetable fiber or fibers before adding the water, is also an advantageous and important aspect of the process, making it possible to obtain particularly suitable blocks. homogeneous and resistant. An advantage of the invention is that this method is simple to implement and that this manufacture is carried out cold requiring no baking of the mixture to obtain a stability of the material. In a particular embodiment of the process, the plant fibers are preferably minced, or crushed, or shredded and then dried in order to obtain a homogeneous mixture with the hydraulic binder called blast furnace slag and with the hydraulic binder called cement, and thus to allow better mechanical strength and better water impermeability in the end. The blocks thus produced can be stored or stored in any suitable condition. In the storage phase, the parts or molds can be placed in a hardening or drying chamber in order to accelerate drying and thus save time.

The mixture can be molded into molds of various shapes and sizes. Preferably, the compressed agglomerated vegetable fiber blocks are molded in molds having a lid for pressing and the mold comprises a means for locking the lid either by its weight or by releasable locking in the demoulding phase at a predetermined height to maintain the pressure until the binder is set. The principle of operation of an automatic production line for manufacturing blocks is described by the diagram figure 3, and following the detail below. 10 a - silos for hydraulic binders called blast furnace slag and called cement, and plant material, for storage of raw material. b - concrete mixing plant with mixer to mix the dry mix first the hydraulic binders, then the plant material, and then humidification with water to obtain a concrete. C - Pouring the concrete into a mold then press pressing and blocking the concrete by the mold cover. d - storage of molds horizontally or vertically for hydraulic binders with sorting robot, first come and first out for demolding. 20 th - demolding with return of mold parts to the press to remake blocks. f - steaming of the demolded blocks in a steaming tunnel without heating, just mechanically ventilated. g - palletizing palletized blocks after baking. 25 h - storage of block pallets on park. Thus, a particular object of the invention resides in the use of a block as defined previously as a carrier element or as a roofing element in the field of the building. The blocks can be used for the realization of walls, partitions, beams, joists, vaults, floors, fence, tile-like roofing element or other, etc. Another object of the invention relates to a plant fiber adhesive mortar, characterized in that it comprises fine sawdust-type vegetable fibers, a hydraulic binder called blast furnace slag and a hydraulic binder called cement, and in that that it is obtained by the dry blending at first hydraulic binders called blast furnace slag and called cement, and then vegetable fibers 10 fine particle of sawdust, and then moistened with water. Preferably, a glue mortar will be made of wood fibers, characterized in that it comprises sawdust-type fine wood fibers, a hydraulic binder called blast-furnace slag and a hydraulic binder called cement, and in that It is obtained by the dry blending at first hydraulic binders referred to as blast furnace slag and called cement, and then sawdust fine wood fibers, and then moistened with water. Advantageously, the adhesive mortar comprises vegetable fibers of fine particles of different sawdust type mixed together, for example 20 of the type of leaves of tree, shrub, pine cone, pine needle, straw, reeds, hemp, flax, wood, cellulose, bamboo, palm stalk, etc., a hydraulic binder called blast furnace slag and a hydraulic binder called cement, and is obtained by the dry blending at first hydraulic binders called blast furnace slag and cement, followed by sawdust-like fine vegetable fibers, and then wetted with water. Furthermore, the adhesive mortar may furthermore contain one or more adjuvants for coloring, accelerating or retarding binding of the binder, water-repellency, fire-proofing, fungicidal or insecticidal treatment, and the use of the adhesive. 1 1 13 fluidification of the mixture, faster curing and high performance mechanical strength. The invention will be better understood and other features and advantages will appear more clearly on reading the detailed description given below by way of example. A typical method of making the blocks is as follows. For a total of 100% representing the total volume of dry matter, a large proportion of fine particulate plant fibers having a volume of the order of 65% to 95% is mixed with a hydraulic binder called blast furnace slag and a hydraulic binder called cement, the volume of the dry matter is of the order of 5% to 35%. The typical method of making the blocks is as follows, for a total of 100% hydraulic binders, the dry blend of the hydraulic binders is composed of 20% to 70% hydraulic binder called blast furnace slag and 30% to 80% hydraulic binder called cement. The dry mix of the hydraulic binders at first, then vegetable fibers, is then moistened with water. In this respect, the water dosage varies depending on the nature of the fine-particulate plant fibers, it can be in the range of 10% to 30% of the total volume of solids. In a particular mode of implementation, the method of making the blocks is as follows. For a total of 100% representing the total volume of dry matter composed of hydraulic binders called high-blast slag and called cement, and vegetable fibers of the type of fine-particle wood fibers, a significant proportion of fiber-type plant fibers. fine wood particles representing a volume of the order of 40% to 90% and a proportion of other vegetable fibers representing a volume of the order of 5% to 25% are mixed with hydraulic binders called blast furnace slag 30 and called cement, the volume of the dry matter is 3004 7 1 1 14 of the order of 5% to 35%. The dosage of water varies according to the nature of the plant fibers, it can be of the order of 10% to 30% of the total volume of dry materials (hydraulic binders, plant fibers and wood fibers). Then this wet mixture is poured into a mold and then is strongly compressed in a volume proportion of for example between 5% and 50%, to make the material very compact. Under the effect of this high pressure, most of the residual air is removed forming a block of compacted plant fibers. Maintaining the pressure to the setting of the hydraulic binders is essential to maintain the compactness of the agglomerate, the finely compressed and interlocking fine particulate plant fibers tending to elastically straighten up as long as the Hydraulic binders have not frozen the final shape. This is a high sustained compression gives a dense material providing interesting characteristics, including good resistance to punching compression, with a value greater than 1 MPa, typically of the order of 0.5 to 7 MPa, for example measured on a block of 5 cm3. This block has a thermal insulation power similar to that of the plant used, a fire resistance improved by the high density and the coating of plant fibers by hydraulic binders, and having no deformation or degradation by the water, as well as better impermeability to water for producing load-bearing elements for the construction and roofing elements like tile or other. In addition, the faces of the block strongly compressed against the walls of the mold are substantially smooth and follow reliefs that can be made on the walls, which allows for the realization of finished blocks directly after demolding with smooth faces comprising relief decorations . These blocks have a density of between 400 and 1200 kg / m3 which is clearly - lower than that of the agglomerated concrete blocks, which facilitates their handling and reduces the self weight of the structures. Blocks can also be made, each covering a larger wall or cover surface for faster mounting. In addition, as for wood, these blocks can be cut, drilled, and receive nails or screws without ankle. In addition, various adjuvants may be added for the acceleration or retardation of the setting of the binder, the coloring of the material, its water repellency, its fireproofing, the fungicidal or insecticidal treatment, the fluidification of the mixture, for faster curing and a high performance mechanical resistance. Complements may also be added to enhance the mechanical strength of the block, such as metal fibers (notched steel, corrugated, stainless amorphous cast iron), synthetic fibers (glass fiber, carbon, polypropylene). Optical fibers giving a luminous effect can be added for decoration. A mineral filler such as sand or silica fume can be incorporated into the mixture to increase the hardness of the block. However, the addition of such a load is not a preferred embodiment because increasing the weight of the material which thus becomes equivalent to the concrete. In addition, the block may have on the face exposed to the weather in the case of a cover element a surface coating by application of paint or material (bitumen slate, clay powder, resin, etc.) to obtain a color (slate, tile, etc.) and a complementary protection of impermeability. Preferably, the vegetable fibers fragmented into fine particles incorporated come from the recovery of waste or crops. These plant fibers are of good quality. These plant fibers require preferably chopping, or grinding, or shredding, and drying prior to use. These plant fibers give the block flexibility, good dimensional stability, good thermal insulation (thermal conductivity 0.12 W / mK), an economic cost thanks to the waste used, a light weight, and a better carbon footprint by storing CO2. , making it possible to produce load-bearing elements for the construction and roofing elements of the tile or other type. Preferably, the hydraulic binder called blast furnace slag gives the block a high mechanical strength, better impermeability to water, a lighter color, better fire resistance, better resistance to sulphates and chloride ions, better resistance to frost and thaw, better resistance to seawater and acidic water, an economic price because it is a waste compared to the hydraulic binder called cement which is expensive in raw material prices, 10 and a balance sheet performing carbon by reducing the CO2 emissions into the atmosphere compared to the hydraulic binder called cement. Preferably, the hydraulic binder called cement gives the block good mechanical strength and good fire resistance, but has a poor carbon balance because of these significant CO2 emissions, a high price compared to the hydraulic binder called high-grade slag. furnaces, and various disadvantages described and discussed in the previous paragraph on the advantages of using the hydraulic binder called blast furnace slag. In general, the compressed agglomerated vegetable fiber blocks produced according to the invention may comprise cells to reduce the quantity of material used, the weight and more particularly make it possible to obtain significant performances in terms of thermal resistance greater than 2. , 50 m2 K / VV, an increase of more than 50% of the thermal performance compared to a solid block, to reduce the cost 25 by reducing the raw material necessary to make a block, and to have a better acoustic performance . They may also include holes according to the thickness or surface grooves which end to end from one block to the other are passages for electrical ducts or pipes for example, and also constitute sockets to ensure sealing of connections between wall or roof elements of the tile or other type. They may also include hooking reliefs to be fixed on a blanket-type support. Preferably, the blocks will be honeycomb honeycombed as shown in FIG. 1 with cavities in the form of cylindrical tubes interlocking into each other and FIG. 2 with cavities in the form of hexagonal tubes. interlocking into each other in order to achieve thermal performance greater than 2.50 m2 K / W, an increase of more than 50% in thermal performance compared to a solid block, this also allows to have a better acoustic performance, to reduce the cost by decreasing the raw material needed to make a block, and to reduce the final weight of the material. The hydraulic binders used to make the adhesive mortar are based on hydraulic binder called blast furnace slag and hydraulic binder called cement. In this respect, it is possible to use any type of blast furnace slag. In this respect, it is possible to use any type of commercially available cement, such as standard cements or any other quality of cement. Preferably, a dry mix at first hydraulic binders called blast furnace slag and called cement, then plant fibers fine particles and then moistened with water, allows for a glue mortar used for assembly of building blocks made of vegetable fibers, or any other building block made of wood fibers. This mixture thus makes it possible to maintain a product homogeneity similar and identical to the building block, and this in order to avoid a different reaction of the materials as a function of a temperature change or variation that can bring about an expansion. In a particular variant, a dry mix at first hydraulic binders called blast furnace slag and called cement, then wood fiber fine particles of sawdust, and then wetted with water, allows to produce an adhesive mortar for the assembly of building blocks made of vegetable fibers, or of wood fibers, or any other building block made of cellulose fibers. This mixture thus makes it possible to maintain product homogeneity that is similar and identical to the building block, and this in order to avoid a different reaction of the materials as a function of a temperature change or variation that can bring about an expansion. According to another variant, a dry mixture at first hydraulic binders called blast furnace slag and called cement, and then vegetable fibers in fine particles of sawdust, for example of 10 type leaves of tree, shrub , pinecone, pine needle, straw, reeds, hemp, flax, palm stalk, bamboo, etc., then moistened with water, allows for a glue mortar used for the assembly of blocks of construction of vegetable fibers, or of wood fibers, or any other building block made of cellulose fibers. This mixture thus makes it possible to maintain a product homogeneity similar and identical to the building block, and this in order to avoid a different reaction of the materials as a function of a temperature change or variation that can bring about an expansion. It is preferable to respect the same proportions of component 20 in the dosages of the adhesive mortar mixture as those of the building blocks and this in order to have homogeneity in the assembly between the building blocks and the adhesive mortar. It is also possible to provide a composition of adhesive mortar with a mixture of different vegetable fibers in fine particles, for example of the type of tree leaves, shrub, pine apple, pine needle, straw, reeds, hemp, flax, wood, cellulose, palm stalk, bamboo, etc., and hydraulic binders called blast furnace slag and called cement, then moistened with water. In addition, various adjuvants can be added to the various mixtures proposed, for the acceleration or retardation of the setting of the binder, the coloring of the material, its water-repellency, its fireproofing, the fungicidal or insecticidal treatment, the fluidification of the mixture, for faster hardening and high mechanical strength. In addition, the block may have on the face exposed to the weather in the case of a cover element a surface coating by application of paint or material (bitumen slate, clay powder, resin, etc.) to obtain a color (slate, tile, etc.) and a complementary protection of impermeability.

Claims (21)

CLAIMS1 - Compressed agglomerated vegetable fiber block, characterized in that it comprises vegetable fibers and hydraulic binders called blast furnace slag and called cement, and in that it is obtained by a process in which an initial mixture comprising plant fibers which are preferably chopped or crushed or shredded into fine particles and hydraulic binders referred to as blast-furnace slag and called cement are kept under pressure for the duration of setting of the hydraulic binders, the fine-particle vegetable fibers representing at least 65%, preferably 65% to 95%, of the total volume of the dry matter of the initial mixture. 2 - block agglomerated compressed vegetable fibers according to claim 1, characterized in that it has a density greater than about 400 kg / m3. 3 - block agglomerated compressed vegetable fibers according to claim 1 or 2, characterized in that it has a puncture compression strength greater than 0.5 MPa. 4 - block agglomerated compressed vegetable fibers according to one of claims 1 to 3, characterized in that the plant fibers fine particles come from wood, palm tree, bamboo, tree leaves, shrub, pinecone, pine needle, straw, reeds, hemp, flax, etc. obtained after recovery of waste or crops, more preferably wood fibers obtained after recovery of waste or crops. 5 - Bloc agglomerated compressed vegetable fibers according to one of claims 1 to 4, characterized in that the binders are based on blast furnace slag and cement. 6 - block agglomerated compressed vegetable fibers according to one of claims 1 to 5, characterized in that it is produced from a mixturecomprenant, for a total of 100% representing the volume of the dry matter, 65% 95% of vegetable fibers in fine particles and 5% to 35% of hydraulic binders, and a quantity of water of between 10% and 30% of the total volume of the dry matter. 7 - block agglomerated compressed vegetable fibers according to one of claims 1 to 6, characterized in that it is produced from a mixture of hydraulic binders comprising, for a total of 100% representing the volume of the binder material hydraulic, from 20% to 70% of hydraulic binder called blast furnace slag and from 30% to 80% of hydraulic binder called cement. 8 - Bloc agglomerated compressed vegetable fibers according to one of claims 1 to 7, characterized in that it is produced from a mixture comprising, for a total of 100% representing the volume of the dry matter, 40 % to 90% vegetable fibers of fine particles of wood fibers, 5% to 25% of other vegetable fibers and 5% to 35% of hydraulic binders, and a quantity of water of between 10% and 30% total volume of the dry matter. 9 - block agglomerated compressed vegetable fibers according to one of claims 1 to 8, characterized in that the mixture further contains one or more adjuvants for coloring, acceleration or retardation of the setting of the binder, water repellency , fireproofing, fungicidal or insecticidal treatment, fluidification of the mixture, faster curing and high performance resistance. 10 - block agglomerated compressed vegetable fibers according to one of claims 1 to 8, characterized in that the face exposed to the weather in the case of cover element receives a surface coating by application of paint or material (bitumen slate , clay powder, resin, etc.) to obtain a color (slate, tile, etc.) and additional protection. 3004 7 1 1 22 11 - Bloc agglomerated compressed vegetable fibers according to one of claims 1 to 10, characterized in that the mixture further contains reinforcing fibers of the agglomerated block. 12 - block agglomerated compressed vegetable fibers according to one of claims 1 to 11, characterized in that it has a density greater than 400 kg / m3. 13 - Process for the preparation of a compressed agglomerated vegetable fiber block, comprising the steps of forming or pouring into a mold, a mixture comprising plant fibers which are preferably minced, or crushed, or shredded into fine particles and then dried, a hydraulic binder called blast furnace slag, and a hydraulic binder called cement, and then hydrated with water, the fine-particle vegetable fibers representing at least 65%, preferably 65% to 95%, of the total volume of the dry matter of the initial mixture, then to apply and maintain the mixture under pressure throughout the setting time of the hydraulic binders. 14 - Use of a block of compressed agglomerated vegetable fibers according to one of claims 1 to 12 as a construction element in the building field. 20 15 - Use of a block of compressed agglomerated vegetable fibers according to one of claims 1 to 12, as a roofing element in the field of the building. 16 - block agglomerated compressed vegetable fibers according to one of claims 1 to 12, characterized in that it has cells in the form of cylindrical tubes or hexagonal tubes, interlocking next to each other to form a honeycomb structure, in order to obtain thermal performance greater than 2.50 m2 KM /. 17 - Vegetable fiber adhesive mortar for the assembly of blocks according to claims 1 to 12, characterized in that it comprises sawdust-type fine vegetable fibers, a hydraulic binder called blast furnace and a hydraulic binder called cement, fine sawdust-type vegetable fibers representing at least 65% of the dry matter volume of the initial mixture, and in that it is obtained by the dry blending at first hydraulic binders called blast furnace slag and called cement, then vegetable fibers in sawdust-like fine particles and then moistened with water. 18 - plant fiber adhesive mortar according to claim 17, characterized in that it comprises vegetable fibers of fine particles of different sawdust mixed together for example of the type of leaves of tree, shrub, pine cone, pin, straw, reeds, hemp, flax, wood, cellulose, palm stalk, bamboo, etc., and hydraulic binders and in that it is obtained by mixing with first dry hydraulic binders called blast furnace slag and called cement, then plant fibers sawdust fine particles and then moistened with water. 19 - Fine sawdust-type vegetable fiber glue adhesive according to one of Claims 17 to 18, characterized in that the binders are based on blast-furnace slag and cement. 20- fiber adhesive mortar according to one of claims 17 to 19, characterized in that the mixture also contains one or more adjuvants for coloring, accelerating or retarding the setting of the binder, water repellency, fireproofing, fungicidal or insecticidal treatment, fluidification of the mixture, faster curing and high performance mechanical resistance. 21 - A method of automatic manufacture of a block according to one of claims 1 to 12 or according to claim 16, characterized in that the raw materials plant fibers, blast furnace slag and cement are stored in the silos, the raw materials are then dosed and fed into the mixer and then mixed dry and then with water, then this mixture is introduced into molds and pressed to obtain the desired final shape, then these filled molds are brought to a storage area in order to ensure the time necessary for the binding of the binders to be then demolded, then these full molds are brought to be demolded, then following the demolding the empty molds return to the press to receive the mixture and the finished blocks from molds are directed to a steaming chamber to accelerate their drying, these blocks are then brought and stored on pallets to be transported easily to a final stockyard of finished products.