HK1115114B - Blocks of wood agglomerate - Google Patents

Description

The present invention relates to blocks of wood which can be assembled into structures by means of an assembly device and to a process for manufacturing such blocks.

It is known that small-sized wood pellets are used to form blocks for building by agglomeration with a hydraulic binder, e.g. cement.

The construction of such blocks is described in document FR-A-2700162 which presents a process for preparing wood pellets and agglomeration to reduce the dimensional differences of the agglomerated blocks subjected to varying climatic conditions.

The preparation of the granules is complex and increases the manufacturing costs. The mineral load has the disadvantages of increasing the density of the material and the weight of the blocks and of diminishing the effect of the advantages of wood, which is in a reduced proportion in the composite obtained, including the thermal insulation qualities.

Other aggregates containing wood have been mentioned in the literature. For example, application WO95/32161 concerns a block containing 30 to 70% by weight of wood and 10 to 40% by weight of cement. Application WO90/15205 concerns aggregates containing fibres, cement and a significant amount of reclaimed sludge (up to 45%). The blocks thus constructed are hollow, have no significant strength and are mainly intended for the manufacture of formwork.

Application WO85/03700 concerns aggregates including wood, cement and silicon dioxide. These materials have a low density, resulting in particular from the application of a point pressure, and are mainly used for the manufacture of panels.

Application FR 2,680,336 concerns the manufacture of aggregate honeycomb pallets, again low density materials, the composition of which is not specified and which are not suitable for use in the construction sector.

Application EP1 057 601 concerns a process for manufacturing a shutter receiver by pressurised casting of a mixture of wood, cement and a chemical inerting agent. This application mainly concerns the casting device but does not provide any details on the composition of the material. In addition, the pressure applied is partial and does not allow the cement to be taken up, so that the casting element is not solid and fragile. In addition, the presence of a chemical inerting agent poses a risk of pollution.

Application CH 611 550 refers to the manufacture of decorative panels using wood aggregate.

Thus, there is no previously available material in wood clumps suitable for use in the construction industry.Earlier documents mainly concern fragile or low density clumps for the manufacture of panels or formwork, but not suitable for the manufacture of load-bearing elements.

The present invention is intended in particular to avoid these drawbacks and to provide a simple, efficient and economical solution to the problem of producing a composite material providing aggregate blocks of wood with a high proportion of wood and having certain characteristics similar to those of raw wood.

The blocks of the invention are advantageously obtained by a process in which an initial mixture of wood particles and a hydraulic binder is kept under pressure for the entire time the binder is held. The blocks of the invention have excellent mechanical properties, in particular in terms of resistance to compression, water and fire, and are quite suitable for use as a building element. These blocks are particularly advantageous over existing materials, such as concrete, in particular due to their reduced weight.

The blocks of the invention have a density preferably greater than about 500 kg/m3, typically greater than 600 kg/m3, preferably 800 kg/m3.

In addition, the blocks of the invention are preferably prepared from a mixture containing at least 75% by volume of dry matter of wood particles, preferably 75% to 95%, typically 80 to 95%.

In addition, the blocks of the invention have an advantageous puncture compression resistance of more than 3 mPa, typically exceeding 10 mPa for a block of 5 cm3.

Preferably, the aggregate wood blocks are produced from a mixture comprising, for a total of 100% of the dry matter volume, 75% to 95% of wood particles and 5% to 25% of hydraulic binder, and a quantity of water between 10% and 30% of the total dry matter volume.

The hydraulic binder used may be cement, lime or plaster, preferably cement based.In this respect, it is possible to use any type of commercially available cement, such as standard cement (in particular 32/5 cpj cement) or any other grade of cement.

In a preferred embodiment of the invention, wood particles include wood chips, possibly mixed with plant fibers. These may include thin wood chips, for example chips made by machine tool cutting tools. Advantageously, wood particles come from healthy wood, and are essentially free of bark, fir, and/or sap. Preferably, wood particles come from resinous (such as pine, fir, maple) or whitewood (such as birch, beech, poplar, maple, etc.).

In one particular implementation, a proportion of the wood particles is composed of plant fibres, so that in particular blocks according to the invention the volume of wood is reduced by between 5% and 25% and compensated by the same percentage by the intake of plant fibres, e.g. hemp-type, flax, etc. Hemp plant fibre is particularly used because it also has a natural, non-chemical fungicidal and insecticidal power.

In one particular application, clumped wood blocks are produced from a mixture comprising, for a total of 100% of the dry matter volume, 50% to 90% of wood chips, 5% to 25% of vegetable fibre and 5% to 25% of hydraulic binder, and a quantity of water between 10% and 30% of the total dry matter volume.

In a particular embodiment, the block also contains one or more adjuvants, which allow the properties of the blocks to be adapted or improved. These include adjuvants for staining, accelerating or delaying binding, hydrofugation, fire retardation, fungicide or insecticide treatment, fluidization of the mixture, faster curing, obtaining a high performance mixture, reinforcing fibers from the agglomerated block or a mineral load. Any adjuvant usable in concrete can be implemented in the present invention.

The blocks of the invention may have a variety of shapes and thicknesses, depending on their intended use (bearing wall, panel, floor, roof, beam, street furniture or housing, etc.).

A key advantage of the agglomerated block according to the invention is that it contains a high proportion of wood, which, by maintaining pressure, makes it possible to obtain a dense material with relatively little binder.

A particular object of the invention thus consists of a compressed wood block comprising wood particles and a hydraulic binder, obtained by a process in which a dry initial mixture comprising wood particles and a hydraulic binder is moistened (by water) and then poured into a mould and kept under pressure for the duration of the binding.

Another subject of the invention is a process for preparing a block of wood in a clump, consisting of the steps of forming or pouring into a mould a mixture of wood particles and a hydraulic binder, moistened with water, and then applying and maintaining the mixture under pressure for the duration of the binder's holding.

Preferably, the initial mixture shall comprise, for a total of 100% of the dry matter volume, 75% to 95% of wood particles, 5% to 25% of hydraulic binder, and a water content of 10% to 30% of the total dry matter volume. Furthermore, as indicated above, the mixture may contain one or more adjuvants chosen from among adjuvants for e.g. staining, acceleration or delay of binder uptake, hydrofugation, fire retardation, fungicide or insecticide treatment, fluidification of the mixture, faster curing, high performance mixture, aggregate block reinforcement fibres or mineral load.

The pressure applied to the mixture can be adjusted by the professional according to the desired properties and use.In a particular implementation it is less than about 1 mPa, preferably less than about 0.8 mPa, and can be for example 0.1 mPa.

An advantage of the invention is that the process is simple to implement, requiring no complex physical or chemical treatment which would increase the costs and time of implementation.

In the storage phase, the parts or molds can be placed in a curing chamber to speed up drying and thus save time.

The mixture can be moulded into molds of various shapes and sizes. Preferably, the blocks of agglomerated wood are moulded into molds with a cover for pressing and the mould has a means of locking the cover at a certain height. This means of locking the mould may have legs blocking the cover by clipping. Side faces of the mould can open to release the cover, rotation means and fixing means allowing the assembly of these side faces.

The advantage is that the mold has holes at its base.

In a particular mode, multiple molds are used, allowing the production of several blocks in parallel.

In one variant, the agglomerated block is a partition element with at its periphery the tongs or grooves to ensure the connection with juxtaposed blocks.

The partition may be flat, or it may have a side-end with slots which fit into slots of another flat partition.

The flat partition element may have two grooves made on a stop on two opposite side faces.

In another variant, the partition element may be curved.

In another variant, the partition element has a longitudinal channel at its top which is continuous with the channel of the other horizontal elements.

The aggregate block may be a long piece of wood forming a hollow beam suitable for filling with a binder.

Alternatively, the block of wood may be a long piece of timber with a longitudinal scrap beam inserted into the wood.

The aggregate block may be a thin, longitudinal piece with a circular arc-like cross-section forming a vault.

The aggregate block may be an upper or lower part of the vaulted room, the outline of which may consist of a circle or arcs which fit on that vaulted room.

The aggregate block may be a longitudinal piece with handles on the side and notches at the end to fit the arched pieces, forming floor trims.

Thus, a particular object of the invention is the use of a block as defined above as a building element in the field of construction.

The invention will be better understood and other features and advantages will be more clearly seen when reading the detailed description given below by way of example and made with reference to the attached drawings in which: Figure 1 is a view of a part of a building constructed with blocks according to the invention; Figure 2 is a view of a standard block; Figures 3 and 4 are cross-sectional views of Figure 2 according to plans III and IV; Figure 5 presents a possibility of assembly between two standard blocks; Figure 6 presents an angle block; Figure 7 presents a cross-sectional view of block 6 according to plan VII; Figure 8 presents an angle block following a variant,Figure 9 is a cut-out view of Figure 8 according to Plan IX: Figure 10 shows a chain block, Figure 11 shows a cut-out view of Figure 10 according to Plan XI; Figure 12 shows a chain block with floor integration, Figure 13 shows a cut-out view of Figure 12 according to Plan XIII; Figure 14 shows a mould for the manufacture of clumped wood blocks; Figures 15 and 16 show details of the mould in Figure 14; Figure 17 shows a floor made of clumped wood blocks; Figure 18 shows a block of the hourdi type,Figures 19 and 20 are cut-out views according to plans XIX and XX;Figure 21 shows a half-hollow beam,Figure 22 shows the assembly of two half-beams between them;Figure 23 shows a full beam;Figure 24 shows a curved block,Figures 25 to 27 show assemblies with curved blocks;Figure 28 shows a curved chain block;Figure 29 shows an aggregate block of wood floor including vaulted blocks;Figures 30 to 32 show elements of the musher floor according to Figure 29; andFigure 33 shows a mould for the manufacture of multiple aggregate wood blocks;Figures 34 to 38 show details of multiple aggregates of Figure 33;Figure 39 shows a treme of blocks and treme of voids;Figure 39 shows a treme of blocks and treme of elements of this floor.

Figure 1 shows schematically parts of partitions of a building constructed from blocks made according to the invention. These blocks form load-bearing elements linked together which allow to obtain a rigid structure capable of supporting the weight of a building. The partitions include as basic elements the standard blocks 10, corner blocks 20, half-angle blocks 30, and chain or lintel blocks 38.

Figures 2 to 13 detail these different blocks with binding elements. The standard block 10 shown in Figures 2 and 3 is a flat, overall parallel-epipedal element, the two large faces being the inner and outer faces of the load-bearing partition, the thickness of this block being relatively small relative to its height and its width being the thickness of the partition.

A longitudinal 12 tab is centered on the upper face and on one side, a longitudinal 14 groove is also centered on the lower face and on the other side. The 12 tabs are slightly lower in height and width than the depth and width of the 14 grooves respectively so as to allow the 12 tabs to be embedded in the 14 grooves to guide the parts relative to each other, with a lateral and a depth-based groove to allow the interposition of a glue film deposited when the elements are assembled.

In addition, the 12th and 14th grooves may have slightly sloping side faces, the width of these elements decreasing as they move away from the face of the block, and the outer terminals of the 12th or inner grooves of the 14th grooves may be rounded to facilitate the unmolding of these blocks after material has been taken.

In general, the basic elements are assembled horizontally in succession from each other in the same direction. In some special cases, these elements can be opposed, with two side faces with grooves 14 facing each other. The assembly of blocks 10 is then carried out as shown in Figure 5 by a connecting blade 16 of the same thickness as a tongue and twice the width of a groove, which is simultaneously lodged in the two grooves 14 facing each other.

In a vertical plane, the elements are superimposed with the upper tongue-rings in the same way embedded in the lower grooves of the upper block.

Figures 6 and 7 show corner blocks 20, Figures 8 and 9 show half-angle blocks 30, the corner block 20 is similar to a standard block, but the side opposite the one with a groove 14 has a height-dependent sequence of three slots 22 of a width roughly equal to the width of the intermediate slots 24. The height of these slots 22 is roughly equal to the thickness of the block 20. These slots 22 are then inserted into complementary slots 24 made on the side opposite the one with a tongue 12 of another corner block 30, alternating these slots 24 with two slots 22.

To strengthen the connection between the two partitions forming the angle, a vertical rod is introduced after assembling the corner blocks into vertical holes 26 located in the centre of the gaps 22 in the two sets of blocks and half blocks of angle 20 and 30, the diameter of this rod allowing the rod to be coated with a glue to seal the whole.

Figures 10 to 13 show blocks 38, 40 performing horizontal chaining of a partition or the realization of lintels placed above an opening. These blocks 38, 40 have a reduced height compared to standard blocks and a horizontally elongated shape. The lower face has a longitudinal groove 14 which receives the tongue from the upper face of the block below. The top forms a channel 32 along the length of the block, it is bounded by three relatively thin walls, the lower face and the two side faces.

The chain blocks 38, 40 are fitted to each other by a stapler 34 at the end of one block which fits into a mortise 36 at the other end of the next block. In this way, a continuous channel 32 is made around a partition and following the angles, in this channel irons are deposited and then a binder, for example concrete, is cast to make a chain.

Alternatively, a particular chain block 40 can be used for the integration of a floor. One of the side walls 42 of the chain block is lower than the other, this shift allows to integrate the connection of a horizontal floor that is supported on top of this side wall 42 by filling the height difference.

The process of making blocks is as follows: for a total of 100% of the total dry matter volume, a significant proportion of wood chips representing a volume of about 75% to 95% are mixed with a hydraulic binder, e.g. cement, lime or plaster, with a dry matter volume of about 5% to 25%. The dry mixture is then moistened.

In a particular implementation, the process of making blocks is as follows: for a total of 100% by volume of wood, dry wood of the hydraulic binder and vegetable fibres, a proportion of wood chips representing a volume of 50% to 90% and a proportion of vegetable fibres representing a volume of 5% to 25% are mixed with a hydraulic binder, e.g. cement, lime or plaster, with a volume of dry matter of 5% to 25%; the water dosage varies depending on the nature of the chips and the wood essence, it may be in the range of 10% to 30% of the total volume of dry wood (hydraulic binder, vegetable and fibre).

The pressure is maintained until the binding is taken up, and the pressure is essential to keep the binding compact, as the chips are tightly compressed and nested together, tending to straighten by elasticity until the binding has frozen into the final shape. This is a strong wood, which maintains a strong compression strength, giving it a strong dense puncture, which gives it interesting characteristics, including good compression strength, with a density of more than 3 mPa, typically about 5 or 6 mPa.

In addition, the block faces heavily compressed against the walls of the mould are practically smooth and follow reliefs that can be made on the walls, which allows to make finished blocks directly after demolding with smooth faces with embossed decorations. These blocks have a density between 500 and 1200 kg/m3 which is significantly lower than that of aggregate concrete blocks, which facilitates their handling and reduces the own weight of the structures. Blocks each covering a larger partition surface can also be made to ensure faster mounting.

Additionally, various adjuvants may be added to accelerate or delay binding, color the material, waterproof it, flame retardant it, fungicide or insecticide treatment, fluidify the mixture, for faster curing or to achieve a high performance mixture. Additions may also be added to strengthen the mechanical strength of the block, such as metal fibers (crinkled, corrugated, amorphous stainless steel), synthetic fibers (glass fibers, carbon, polypropylene). Optical fibers giving a light effect may be added for the load equalisation. A mineral such as its metallic or metallic decoration can be incorporated into the block to increase the load. However, such additions do not increase the weight of the block, which is not the preferred way of loading.

Preferably, the embedded fragmented wood comes from the carpentry, cabinetry or timber industries and is the thin chips left by the cutting tools of machine tools such as a drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, drill bit, etc.

Figures 14 to 16 show an example of a mould 50 used for the manufacture of aggregate blocks according to the invention. It has a base 52 of open parallel-epipedal shape on top which is closed by a lid 54, these various elements are made from sheet metal. Base 52 has a bottom 62 drilled with 64 small holes for the evacuation of air and excess water in the material, this bottom is supported on the lower 70 edges of the sides 56, 58, 60 formed by a fold of the sheet metal sides turned inside the base 52. The outline of the base 62 has chamferins turned towards the lower face of the base, which fit on the rays formed by the folds of the sheets to allow a good support of the sheet metal bottom on the lower 70 sides.

At a height h 68 above base 52 is the lower end of elastic legs 66 formed by cuts of the sheets of the sides 56, 58, 60, these lower ends slightly retract into the base 52. For the compression of the material previously cast into base 52 forming a mould, a press acts vertically on the cover 54 stiffened by ribs 68 which descends into base 52. After a descent from a height h corresponding to the compression rate chosen for this material, cover 54 pushes the elastic legs 66 outwards to form its passage, then once in a mixed form, these legs 66 return to their elasticity and achieve a cover 54 verging that can no longer be held.

This process of making with a mould 50 now pressing by itself is particularly interesting because after a press compression the blocks whose binder is being taken are evacuated and stored on a waiting area freeing the press which can continue to compress the following molds.

For block unmolding after the binding is taken, the mould opens to release the clumped block. Side faces 58 of the mould are connected to back face 56 by 72 hinges, and front face 60 is connected to each side face 58 by two locks 74. Once the binding is taken, the locks 74 are opened, front face 60 is released, side faces 58 rotate on their hinges 72 which releases the lid 54 of the legs 66, the clumped block is removed, and the mould can be re-configured for the next mould.

On the basis of the same principle, including a system of rapid locking of the face of the mould used for compression, for example by clipping, many shapes can be made, such as corner blocks 20, 30, chain blocks 38, 40 or blocks 17 to 23.

Other examples of block construction are given in Figures 17 to 23 which show aggregate blocks used for the construction of load-bearing floors. Figure 17 shows a floor 80 with 82 half-beams paired paired symmetrically to a vertical longitudinal plane. Figures 21 and 22 detail this assembly, the half-beams 82 are generally shaped like a U laid flat, the U openings face each other, the lower wings join and are adjusted by a 90 blade embedded in grooves formed in each of these wings. The upper wings are shorter, supporting blocks or 84 beams which are made of a trimmed trimming which consists of two 86-sided grooves on the opposite side and receiving a half-plane of the 82 flat wings.

The 84-headed hoods have a 12th tongue and a 14th groove on their other two sides to link them together. Once the 84-headed hoods have been placed on the 82 half-beams, a scrap metal not shown here is placed in the hollow of the beams and a cement-based binder, for example, is cast to fill these hollows, which can then cover the entire floor to make a compression slab.

The half-beams 82 may be of a single length or may be composed of several standard lengths joined together and arranged in a quincunx.

Figure 23 shows a variant of a pre-assembled beam 100 with a cross section in the general shape of an inverted T , a longitudinal scrap 102 is integrated into it when the wood chip mixture is cast, before compression which will form a clumped block according to the invention.

Figures 24 to 27 show curved aggregate blocks 110. As with flat blocks 10, these curved blocks 110 have two large faces forming the inner or outer walls of a partition, but these faces are curved in a horizontal plane.

These curved blocks 110 can be assembled in a horizontal plane with flat blocks 112 on either side, the curved block forming a rounded angle between two flat partitions as shown in Figure 25. The curved blocks 110 can also be assembled in series of four, the concave faces all turned to the same side as shown in Figure 26, to form a circular pole.

Another possible assembly is shown in Figure 27, the curved blocks 110 are arranged horizontally in series of two blocks turned in one direction followed by two blocks turned in the other direction.

Figure 28 shows a clustered block 120 serving as a chain above a curved block 110, its inner and outer radii adjusting to those of the curved block. The chain block 120 has on its lower face a groove that receives the upper tongue of the curved block 110 below, a handle 34 at one end of the block fits into a mortise 36 at the end facing the next block, similarly a mortise above 36 is present at the other end. It forms a channel 32 bounded by two relatively thin walls. The top of the inner wall may be lower to integrate the chain's linkage, as for the chain block floor shown in Figures 12 and 13.

Figures 29 to 32 show a floor consisting of a series of 130 long-shaped wood pieces juxtaposed next to each other, placed at their ends on the lower side walls 42 of a succession of 40 chain blocks forming part of the partitions. The 130 long-shaped pieces cover the entire floor surface, they have a cross section in a circular arc each forming a small arch of thin thickness which gives rigidity to the 130 long-shaped piece and allows it to be self-supporting. 132 connecting holes are made on the sides of the 130 high-shaped pieces to connect these pieces by bolts, in order to ensure an alignment of these differences and improve the overall rigidity.

Top elements 140 and bottom elements 150 are placed in a transverse orientation at the ends of the long-armed parts 130 to close the channel 32 of the chain blocks 40 laterally. The top element 140 has on its lower face a contour symmetrically forming two circle arcs each covering half of a vault 130. The tops of these elements 140 are aligned and form a horizontal plane placed higher than the top of the vaulted parts 130. The bottom element 150 is placed below a vaulted part 130, its lower part aligned with that of the vault 130 in the same horizontal plane rests on the side-vault 42 of the chain block 140.

This self-supporting floor can be used as is or as a foundation for a concrete slab cast on it to make a stronger floor. In this case the upper elements 140 are removed to allow the connection between the concrete of channel 32 and that of the slab. A longitudinal scraper can be inserted into the hollows formed between two arched parts 130.

Alternatively, the floor made with the arched rooms 130 may be reinforced by a fabric of fibres, e.g. glass or carbon fibres, which is glued directly to the top or bottom of the arched rooms.

In addition, the openings above between two vaulted rooms 130 and those below a vault form openings for wires or pipes for the building equipment.

In general, the aggregate blocks of wood made according to the invention may have hollows to reduce the amount of material used and the weight. They may also have boreholes according to thickness or grooves on the surface that end to end from one block to another form passages for electrical sheaths or pipelines, for example.

Figures 33 to 38 show an example of a multiple mould 159 for making clustered blocks according to the invention. It has two parallel sides 172 and two other parallel sides 164 forming a paralleloped open at the bottom for passage of the bottom 161, and open at the top for passage of the lid 160. These different elements are typically made from sheet metal. The sides 172 have elastic legs 165 formed by the cuts of the sheets, the lower end of which is located relative to the top at a height 173. The sides 172 have at the bottom part an element 167 pivoting on an axis determined by the hinges 168.The 172 sides have reinforcements 166 to prevent deformation in pressing. The 172 sides connect to the 164 sides, and are held by fastening or welding. The 164 sides have a hole in the lower part of the corners to place a keypad 169 to lock the rotating element 167. The 164 sides at the end of the mould can receive reinforcements 171 to prevent deformation in pressing. The 161 bottom has reinforcements 163 to prevent deformation in pressing. The 161 bottom by pressure between the 172 and 164 sides pushes the 165 elastic legs downwards outwards to form its passage,The cover 160 has reinforcements 162 to prevent deformation during pressing, this in turn is lowered by pressure between the sides 172 and 164 to compress the material 170 to a height h 173 corresponding to the selected compression rates. The cover 160 pushes the elastic legs 165 outwards to form its passage, then once it has reached below, the legs 165 return to their place by elasticity and achieve a locking of the cover 160 that can no longer rise.Pressure can be released because the 160-cap is clipped and maintains pressure throughout the binding time.

This process of making a multiple 159 mold now pressing by itself is particularly interesting because, after a press compression, the blocks whose binder is being taken can be evacuated and stored on a waiting area, freeing up the press which can continue to compress the following molds.

For the unmolding of the block after the binding is taken, the 169 keys are removed, releasing the 167 elements that pivot and thus releasing the bottom 161, block 170 and top 160, which can be pushed out by pressure between the 172 and 164 sides.

On the basis of the same principle, including a system of rapid locking of the face of the mould used for compression, for example by clipping, many shapes can be made, such as corner blocks 20, 30, chain blocks 38, 40, or blocks 17 to 23.

Figures 39 to 40 show a floor hopper comprising a series of longitudinal pieces of wood 130 juxtaposed next to each other, connecting to the piece 175 to perform a floor hopper. This piece 175 has handles 176 on the side for the arched pieces 130 to rest on, notches 178 at the ends to fit on the arched pieces 130 and fixing holes to hold the whole by means of pull-backs.

Specific examples of blocks of the invention have been made and tested for their properties. - What?

	92%	8%	23%	2 Mpa
	89%	11%	22%	4,8 Mpa
	84%	16%	21%	5,6 Mpa
	81%	19%	16%	8,2 Mpa

Thus, the invention allows the production of aggregate blocks of wood with a strength superior to Siporex and capable of reaching the strength of a concrete block, while having a much lower bulk mass than concrete.

Durability tests were carried out with water, a 5 cm3 block was placed in total immersion in water for 2 months and it was found that there was no degradation of the material and no change in dimensions.

Durability tests were also carried out by first immersing a 5 cm3 block in water for about 1 hour, so that it would soak in the liquid element, and then placing the block in a freezer for 2 days, to observe its freezing behaviour.

Colouring tests were carried out by mixing a water tint with the waste water, and the colour of the block was complete on the whole mass.

Claims (34)

1. A block of compressed wood agglomerate, characterised in that it comprises particles of wood and a hydraulic binder, and in that it is obtained by a process in which an initial mixture comprising particles of wood and a hydraulic binder is kept under pressure throughout the hardening period of the binder, the particles of wood representing at least 75%, preferably from 75% to 95%, of the total volume of dry matter of the initial mixture.
2. A block of compressed wood agglomerate according to claim 1, characterised in that it shows a density greater than 500 kg/m³.
3. The block of wood agglomerate as claimed in Claim 1 or 2, characterized in that it has a resistance to punching compression greater than 3 mPa.
4. The block of wood agglomerate as claimed in any one of Claims 1 to 3, characterised in that the particles of wood comprise wood chips, optionally in a mixture with vegetable fibres, preferably thin wood chips, more preferably shavings made by the cutting tools of machine tools.
5. The block of wood agglomerate as claimed in any one of Claims 1 to 4, characterised in that the binder is based on cement.
6. The block of wood agglomerate as claimed in any one of Claims 1 to 3, characterised in that the binder is based on plaster.
7. The block of wood agglomerate as claimed in any one of Claims 1 to 3, characterised in that the binder is based on lime.
8. The block of wood agglomerate as claimed in any one of Claims 1 to 5, characterised in that it is produced from a mixture comprising, for a total of 100% representing the volume of dry matter, from 75% to 95% approximately of particles of wood and from 5% to 25% approximately of hydraulic binder, and a quantity of water between 10% and 30% of the total volume of dry matter.
9. The block of wood agglomerate as claimed in any one of Claims 1 to 6, characterised in that it is produced from a mixture comprising, for a total of 100% representing the volume of dry matter, from 50% to 90% approximately of wood chips, from 5% to 25% approximately of fibre vegetable and from 5% to 25% approximately of hydraulic binder, and a quantity of water between 10% and 30% of the total volume of dry matter.
10. The block of wood agglomerate as claimed in any one of Claims 1 to 9, characterised in that the mixture also contains one or more adjuvants for dyeing, acceleration or retarding of the hardening of the binder, waterproofing, fireproofing, fungicide or insecticide treatment, liquefaction of the mixture, faster hardening or to produce a high-performance mixture.
11. The block of wood agglomerate as claimed in any one of Claims 1 to 9, characterised in that the mixture also contains reinforcing fibres of the block agglomerate.
12. The block of wood agglomerate as claimed in any one of Claims 1 to 11, characterised in that it shows a density greater than approximately 500 kg/m³, preferably greater than approximately 800 kg/m³.
13. A process for the preparation of a block of wood agglomerate, comprising the steps consisting of forming or pouring in a mould (50) or (159) a mixture comprising particles of wood and a hydraulic binder hydrated by water, the particles of wood representing at least 75%, preferably from 75% to 95%, of the total volume of dry matter of the initial mixture, then applying and maintaining the mixture under pressure while the binder hardens.
14. The process as claimed in Claim 13, characterised in that the mixture is moulded in a mould (50) comprising a cover (54) serving as pressing, and in that the mould (50) comprises blocking means (66) of the cover (54) at a determined height (68).
15. The process as claimed in Claim 14, characterised in that the blocking means of the mould (50) comprise tabs (66) blocking the cover (54) by clipping.
16. The process as claimed in any one of Claims 14 to 15, characterised in that lateral faces (58, 60) of the mould (50) open to disengage the cover (54), and in that pivoting means (72) and fixing means (74) assist in assembling these lateral faces (58, 60).
17. The process as claimed in any one of Claims 14 to 16, characterised in that the mould comprises holes at its base.
18. The process as claimed in Claim 13, characterised in that the mixture is moulded in a mould (159) comprising a bottom (161) blocked by two lateral pivoting elements (167) which are keyed (169), a cover (160) serving as pressing, and in that the mould (159) comprises blocking means (165) of the cover (160) at a determined height (173).
19. The process as claimed in Claim 18, characterised in that the blocking means of the bottom (161) of the mould (159) comprise lateral pivoting elements (167) on an axis by hinges (168) and blockage of the latter by keyway (169).
20. The process as claimed in any one of Claims 18 to 19, characterised in that the blocking means of the mould (159) comprises tabs (165) blocking the cover (160) by clipping.
21. The process as claimed in any one of Claims 18 to 20, characterised in that the lateral pivoting elements (167) are loosened (169) releasing the bottom (161), the block (170) and the cover (160) after the binder has hardened.
22. The process as claimed in any one of Claims 18 to 21, characterised in that the moulds (159) can be juxtaposed and assembled beside one another.
23. The block of wood agglomerate as claimed in any one of Claims 1 to 13 or obtainable by the process as claimed in any one of Claims 14 to 22, characterised in that it constitutes a partition element comprising on its periphery tongues (12) or grooves (14) to ensure binding with juxtaposed blocks.
24. The block of wood agglomerate as claimed in Claim 23, characterised in that the partition element is flat (10).
25. The block of wood agglomerate as claimed in Claim 24, characterised in that the flat partition element (10) comprises on one of its side edges slots (22) which nest with slots (22) of another flat element.
26. The block of wood agglomerate as claimed in Claim 23, characterised in that the partition element comprises two grooves (86) made on an edge of two opposite lateral faces.
27. The block of wood agglomerate as claimed in Claim 23, characterised in that the partition element is curved (110).
28. The block of wood agglomerate as claimed in Claim 23, characterised in that the partition element (38, 40, 120) comprises in its upper part a longitudinal channel (32) which continues other horizontally juxtaposed elements with the channel.
29. The block of wood agglomerate as claimed in any one of Claims 1 to 13 or obtainable by the process as claimed in any one of Claims 14 to 22, characterised in that it constitutes a long element (82) forming a hollow beam to be filled by a binder.
30. The block of wood agglomerate as claimed in any one of Claims 1 to 13 or obtainable by the process as claimed in any one of Claims 14 to 22, characterised in that it constitutes a long element forming a beam (100) comprising a longitudinal reinforcement inserted in the wood agglomerate (102).
31. The block of wood agglomerate as claimed in any one of Claims 1 to 13 or obtainable by the process as claimed in any one of Claims 14 to 22, characterised in that it constitutes a lengthy piece (130) of minimal thickness having a transversal section in an arc of a circle forming an arch.
32. The block of wood agglomerate as claimed in any one of Claims 1 to 22, characterised in that it constitutes an upper element (140) of an arched piece or a lower element (150) of an arched piece, and in that its contour comprises one or several arcs of a circle adjusting on the arched piece (130).
33. The block of wood agglomerate as claimed in any one of Claims 1 to 13 or obtainable by the process as claimed in any one of Claims 14 to 22, characterised in that it constitutes a lengthy piece (175) with tenons (176) and notches (178) so that the blocks (130) adapt perpendicularly and at the end.
34. The use of a block of wood as claimed in any one of Claims 1 to 13 or obtainable by the process as claimed in any one of Claims 14 to 22, as a construction element in the field of the building.