Making wood concrete blocks with your own hands, wood concrete composition, proportions, mixing

How to make it yourself

To make wood concrete you will need wood chips, cement, water, and mineral additives.
To prepare wood chips you will need a special wood waste shredder - a shredder, and to mix the solution - a concrete mixer.

Advice: Machinery can be rented.

There are many recipes for preparing wood concrete; when preparing the mixture, one of the most important conditions is preliminary drying and processing of wood chips. To prevent rotting and increase the fire resistance of the material, the chips are pre-treated with an antiseptic and fire retardant, then dried. Mineral additives are added to the solution or the wood chips are treated and then dried.

Composition and proportions of the mixture

These indicators depend on the purpose of the wood concrete (structural or thermal insulation), the desired grade of wood concrete, the moisture content of the wood chips, and the grade of cement:

• to prepare 1 m3 of structural wood concrete grade B 2.5, take 320 kg of M400 cement, 190 kg of filler and 330 liters of water;
• To prepare 1 m3 of thermal insulating wood concrete grade B 0.35, take 280 kg of cement, 1170 kg of wood chips and 300 liters of water.

Important! There are no exact proportions of the mixture, since cement of the same brand from different manufacturers may differ, and wood chips do not have the same moisture content. Therefore, several control batches may be needed to determine the exact dosage of components.

Proportions of mineral supplement

wood chips

It is advisable to use wood chips from coniferous trees, with the exception of larch; it is possible to use wood chips from deciduous trees. According to GOST, chips should have a size of no more than 25×5×10 mm; with a larger size, the strength characteristics of the material deteriorate; with a smaller size, the consumption of expensive cement increases and the thermal insulation qualities deteriorate.

Attention! Raw materials must be free of rot, mold, foreign particles, and in winter - without snow or ice.

To neutralize sugars in wood, which negatively affect the quality of cement, the wood chips are dried in the sun for at least 3 months, constantly stirring (not in a heap!), or treated with chemical components.

Chemical components

The chemical components used (per 1 m3 of mixture) are technical calcium chloride - 8 kg, or sodium liquid glass - 8 kg, or a mixture of aluminum sulfate with quicklime - 20...25 kg.

When using lime, 1 m3 of wood chips is soaked in lime milk containing 2.2 kg of fluffed lime per 150-200 liters for 3-4 days with regular stirring, then squeezed out. Since this process is quite dangerous due to chemical burns, calcium chloride or liquid glass is more often used at the rate of 2-5% by weight of cement.

Composition adjustments

If during mixing they use cement of a lower or higher grade than the recommended M 400, or too wet chips, then correction factors are applied to the percentage of the components:

• Cement M 300 - coefficient 1.05;
• cement M500 - coefficient 0.96;
• cement M600 - coefficient 0.93;
• with chip moisture content of 20% - coefficient 1.2; in this case, the amount of water is reduced by its content in the wood.

To determine the exact amount of chemical additives, test batches are made: if, when introducing 5% additives, whitish streaks appear on the dried sample, the amount of the component can be reduced.

This video shows what failure to do in proportion can lead to:

Kneading process

To mix wood concrete concrete, you can use a tin tank or bath, but it is easier to mix the components in a mortar mixer. The prepared wood chips are mixed with dry cement and a mineral additive, then water is poured in and kneaded until smooth. The mixture should be moderately moist, but the solution should not drain.

The mixture is fed into the prepared formwork, poured in layers no more than 30 cm high, then compacted.

Wood chips: how to get or where to buy

The best wood chips for wood concrete are made from pine and spruce. You can also use larch, but when mixing it is necessary to double the amount of chemical additives. Among hardwoods, GOST allows the use of aspen, beech, birch, and poplar. The remaining requirements are:

• Maximum dimensions 40*10*5 mm. The optimal parameters of wood chips have been established experimentally: length is about 25 mm, width is 5-10 mm, thickness is 3-5 mm. The strongest wood concrete blocks are obtained from such raw materials.
• The amount of bark should not exceed 10%.
• There should be no dust, sand, soil, or foreign impurities. The chips are removed from small fractions, dust and sand using a sieve, and large foreign inclusions are removed manually (often pieces of soil or stones).
• There should be no visible mold or rot. Example of wood chips

The best wood chips come from lump waste wood. It is first passed through chippers and then crushed in a hammer crusher. The following mechanisms can be used for this:

• Disc chippers with adjustable knives. Not all of them can be adjusted to produce chips of the required size, but the sizes will be close.
• Rotary knife crushers. They produce narrow and not wide chips, and the length is adjustable. That is, this is a good option. There is only one “but”: there are a lot of knives and if used for a long time, they need to be changed or welded (they don’t sharpen). On the plus side, we add that crushers of this type can be used for re-crushing process chips obtained during the first crushing (after reconfiguration).
• Shredders or roller grinders. This is expensive equipment (about 1 million rubles), mostly imported, but it is excellent because it is manufactured for specific chip sizes.

If making wood chips yourself is not an option, you can buy it. If possible, you can negotiate at the factory where wood concrete is produced. Just check the chip parameters. If there is none nearby, you can take chips from under the calibration machines. Some of them can be adjusted so that the chips are not thick.

What is a ready-made wood concrete block?

A type of lightweight concrete are blocks made from wood chips. They are distinguished by their large-porous structure and filler, which is used as wood shavings. Standard products have the shape of a rectangular parallelepiped with dimensions of 0.5x0.3x0.2 m. Block products with other dimensions corresponding to the dimensions of the molding box are also produced. Along with blocks, wood concrete products are produced in the form of slabs, which are reinforced to increase their strength.

Wood concrete includes the following components:

• wood filler in the form of chips of certain sizes;
• special active additives with chemical components;
• binder based on Portland cement M400;
• water, which ensures the plasticity of arbolite solutions.

Chip blocks have a large-porous structure.
One of the conditions for obtaining high-quality material is uniform mixing of the ingredients. First, the mass of each type of feedstock is determined depending on the required amount of solution. Then the weighed components are mixed and the next step is performed - filling the formwork boxes with the solution. To ensure increased block density, the mixture is compacted in molds. It is easy for developers who make expanded clay concrete blocks with their own hands to master this method of producing wood concrete.

Main walls are built from arbolite blocks and internal partitions are erected in low-rise buildings:

• residential buildings;
• economic facilities;
• industrial buildings.

Arbolite is classified into the following types:

• material with a density of up to 500 kg/m3, used for insulation of various types of building structures;
• structural products with a specific gravity of 500-800 kg/m3, which are used for the construction of load-bearing walls.

The use of wood filler and the coarse-mesh structure of the wood concrete mass do not allow the material to be used under heavy loads. You should make sure of the quality of the material when purchasing wood concrete for the construction of a private house. High-quality raw materials are not always used and the working mixture is saturated with liquid glass, which reduces hygroscopicity.

To build a private house, you should make sure the quality of the material

Two ways to fill arbolite walls

There are two main options for filling wood concrete walls with your own hands.

Pressed method of pouring wood concrete, without frame

We stretch the string along the axis of the foundation. Using it as a guide, we install the formwork panels.

We mix the mixture, pour it into the formwork in layers of 20 cm and compact it, adding until the mixture fills the formwork box to the top. Cover the stuffing with plastic wrap and leave.

The next day, we check how well the mixture has gained strength, remove the formwork, place it in a new place, or lift it to the next row. We fill the formwork again with the mixture, compact it, and so on until we complete the wall.

After the layer has set, move the formwork higher

Frame method of pouring wood concrete

From timber 50x60 or 50x70 we make the skeleton of future walls, aligning the frame posts along the cord so that it forms the outer and inner planes of the walls.

After this, we fill the resulting frame with wood concrete, just as in the first option, moving the formwork along the frame slats.

This method is more expensive, but provides higher accuracy, and is more convenient, since you do not need to check how accurately the formwork is positioned every time. We simply move the formwork along the vertical slats of the frame as if along guides.

The construction of the frame increases the cost, but also simplifies the work of pouring wood concrete walls

Wood concrete building blocks - advantages and disadvantages of the material

Wood concrete is gradually gaining popularity in the construction industry due to its serious advantages:

Wood concrete surpasses traditionally used materials in terms of noise absorption

• reduced thermal conductivity coefficient. In buildings constructed from arbolite blocks, temperatures favorable for residential premises are maintained year-round. In addition, due to reduced thermal conductivity, heating costs are reduced;
• sufficient margin of safety. With a compression force of 5 MPa and a bending load of 1 MPa, the material does not collapse. Due to the strength of the material, wood concrete products gradually restore their shape and original dimensions;
• resistance to deep freezing. Manufacturers of wood concrete blocks and slabs guarantee the frost resistance of their products. Tests confirm the preservation of the performance characteristics of the material after 40-60 cycles of intensive cooling followed by sharp settling;
• ability to reduce noise exposure. The noise insulation characteristics of wood chips used as filler make it possible to create favorable conditions for those living in the room by absorbing external noise;
• reduced mass with increased volume. Using light and voluminous wood concrete blocks, it is easy to quickly build the main walls of a house. The reduced mass of block material can significantly reduce the load on the foundation;
• harmless to health and the environment. The technology for manufacturing wood concrete products involves the use of environmentally friendly raw materials. The absence of harmful emissions from wood concrete confirms the harmlessness of the material to others;
• ease of use. Wood concrete can be easily cut into pieces of the required size using available tools. Problematic situations when cutting material and forming channels in it are eliminated. In addition, reinforcing mesh is not required for arbolite plaster;
• maintaining original dimensions under load. Due to the low shrinkage of wood concrete blocks, not exceeding 0.6%, the likelihood of cracks forming on the walls of the building is reduced. The dimensions of the block material are preserved after removal from the molds and drying;
• affordable price. The low cost of the material is ensured by the use of cheap waste that accumulates at woodworking enterprises in the process of manufacturing various products;

Arbolite is harmless to health and the environment

durability. Despite the fact that wood concrete has relatively recently gained popularity in the construction market, it is a building material with a long service life. Safe operation of arbolite buildings is guaranteed for up to half a century.

So, the weaknesses of wood concrete:

• instability of product dimensions. Increased dimensional tolerances are associated with the use by different manufacturers of molds that differ in size. The increased consumption of plaster composition associated with dimensional deviations can be avoided by purchasing blocks from one supplier;
• irreversible changes in the structure of wood concrete under intense heating. And although an open fire does not cause arbolite products to ignite, due to the high temperature associated with sudden heating, smoldering of the chips occurs. This significantly reduces the strength of the material;
• tendency to absorb moisture. Due to the increased hygroscopicity of wood concrete, accelerated moisture saturation of unprotected walls occurs. The surface of the material requires mandatory plastering on the outside and inside of the building. Waterproofing protection of the foundation with which the wood concrete blocks are in contact is also necessary.

Other disadvantages include:

• the possibility of the development of microorganisms due to the reduced concentration of lime;
• the need for additional insulation of wood concrete, which is easily blown;
• characteristic odor associated with the introduction of chemical reagents into the material;
• damage to blocks by various rodents that show interest in it.

When you decide to make wood concrete slabs with your own hands for building a house, familiarize yourself with the advantages of the material and carefully analyze the disadvantages.

Thanks to its complex of advantages, wood concrete is widely used in construction

Features of application in construction

Due to high moisture absorption, monolithic wood concrete requires specific measures for waterproofing walls :

• the distance from the planning ground mark to the bottom mark of the wall must be at least 50 cm;
• on the top of the foundation or plinth it is necessary to lay a layer of waterproofing material or a cement-sand screed with waterproofing with liquid glass;
• protect façade surfaces with plaster, cladding or curtain façade;
• cornice overhang - at least 50 cm.

Structural wood concrete is used for the construction of monolithic external walls with removable or permanent formwork made of plywood, moisture-resistant chipboard or OSB, and boards. Permanent formwork serves as a finishing layer. When using removable or sliding formwork to level the layer and reduce the consumption of cement for subsequent finishing, it is better to wrap the boards with PVC or polyethylene film.

Installation of permanent formwork. We immediately get the façade finished.

Structural wood-reinforced concrete during the construction of 2-story cottages will require additional reinforcement or a load-bearing frame , as well as the installation of reinforced belts under the floor and coating slabs.

Thermal insulation material is used for the insulating layer in masonry or three-layer walls. It can also be used in the construction of frame houses to fill cavities.

Attention!

When installing reliable waterproofing, a screed made of monolithic wood concrete can be used to insulate the floor of the first floor on the ground, over the ceiling, including the attic.

Frame elements in contact with the wood concrete mixture must be protected : metal from corrosion, wood from rotting. The frame racks are installed in increments of 1.2-1.5 m, at the openings of windows and doors. To reduce the load on the walls and foundation, it is recommended to carry out ceilings using wooden beams.

The façade and interior surfaces of wood-concrete walls require protection from moisture. This can be plastering, facade cladding with curtain panels, tiles or bricks, plasterboard cladding, plaster or interior wall cladding.

Formation of arbolite blocks

When the solution is ready, it is poured into a suitable container and now it must be used up within 15 minutes. To form and make wood concrete blocks with your own hands, quite a lot of ways have been invented - in production these are collapsible formworks for 6-12 blocks, and at home they are usually made one piece at a time in homemade stencils.

One of the manufacturing methods in the video:

The wood concrete manufacturing technology provides two molding options:

• Fast removal of formwork - after the initial setting of the cement. Essentially, this is a non-stop process - forming a block (filling the solution into a mold), pressing (or vibro-pressing), stripping and sending it to dry. Together with preparing the solution, even one person can make 80-100 blocks per day. The advantage of the method is the speed of production of new wood concrete blocks and the non-stop process.
• Stripping in 24 hours - after crimping, the block is left in the mold for 24 hours, after which only stripping and drying are carried out. Making wood concrete blocks with your own hands in this way can be even faster, but only if you have a sufficient number of molds in which the wood concrete can be left overnight. The advantages of the method are the close to ideal shape of the block, which, after the concrete has set, does not have the possibility of even the slightest distortion.

The worse the geometry of the blocks, the thicker the cement seams between them will be, which form cold bridges. To reduce thermal conductivity, the blocks are given a zigzag shape, which breaks such a bridge, preventing direct heat outflow.

To form the blocks, a special machine or stencils are used - all this equipment for arbolite blocks can be made with your own hands.

Using the machine

Both devices can be used in any of the methods, but their machine is often made for quick formwork, to increase the rate of production. Their undeniable advantage is the pressing of the block on a vibrating table. The formation process itself is simple and the equipment can be trusted by workers after minimal training.

Operation of the semi-automatic machine on video:

• The finished mixture is poured into a measuring container (1), which moves on the guides (2), pouring the solution into the mold (3).
• The lid (5) of the press is placed on top of the solution (its height can be adjusted with pins (6) for people of different heights) and pressed down with a lever (7).
• After pressing, the vibrating table (8) is turned on. It works for 20-30 seconds and automatically turns off (you can use a simple time relay) - you cannot compact it longer, because then the cement will be shaken off to the bottom of the block.
• The lever leans back (9), the press cover is removed (10) and the press mold rises upward (11), for which the pedal is pressed.

The finished wood concrete block can be taken away for drying (12). After 2-3 days it will gain sufficient strength for transportation.

To use the stripping method after 24 hours, the mold is made collapsible and removable, and the top cover can be fixed in it with latches or in another convenient way. After compaction, the block is removed directly from the mold and sent for settling.

Wood concrete using a stencil

Two main types of molds are used - in the form of a box without a bottom and top, and also a collapsible one, in the form of two letters “G”, which snap together around the bottom to form a rigid box covered with a lid. It, in turn, is also fixed with separate latches, which are embedded in the side walls.

No matter which mold is used, the basic algorithm is as follows:

• The box is being prepared for filling with wood concrete mixture. The through one is placed on a hard surface (1), covered with cellophane (so that the block does not stick), the solid box is wetted from the inside.
• The first layer of the mixture is poured, compacted, a second layer is added on top, and, if necessary, a third and covered with a lid. A pressure (weight or something suitable) is placed on the through box (2); in a collapsible box, the upper part is fixed with latches (3).
• If you have a hammer drill at hand, you can walk it over the lid, this will replace the vibrating table.
• Depending on the technology used, the formwork is removed or the form is left to stand.

If a through box is quickly dismantled, then first it is the one that rises up (4), then the pressure is removed and the lid is removed. The block is sent for drying along with the base on which it was formed.

Preparation of the solution

If it is not possible to keep the wood chips in the air to destroy the sugars, they are subjected to chemical treatment: left in lime milk for 3 days. The wood waste is mixed from time to time. There is no need to dry the wood chips after this. It is only necessary to remove excess solution. In the process of laying such blocks, a solution of different composition is used.

Sand with cement

Recommended proportions of components: 1 share of M400 cement and 2 shares of sand. If you plan to use M500 cement, then prepare 3 parts of sand for 1 part of this material. The components are mixed dry using a construction mixer.

Perlite

Kneading begins by combining water (10 l) and a dry mixture of perlite (2 buckets). When the components are thoroughly mixed, cement is added to them (no more than 0.5 buckets). When working with perlite, it is necessary to wear a respirator, safety glasses and closed clothing.

Glue mixture

Standard scheme: 5 kg of adhesive (dry) and 5 liters of liquid. The mixture is left at rest for 5 minutes. Then the mixing process is repeated. The finished material must be used within 2 hours, then it will lose its properties.

The procedure and features of mixing the solution

First, sufficient sawdust is poured into a container or concrete mixer. After this, water is poured in. Special additives and liquid are mixed separately. At the next stage, the solution is added to a concrete mixer, where the sawdust is soaked. After these manipulations, cement is poured in small portions.

Block molding

Forms for the finished mixture are made or purchased. They should have handles, but without a bottom. Such structures are installed on a wooden base. The solution is poured into them. If the work is done with your own hands, the mixture is laid out in molds in layers, each time tamping the material using a manual vibrating platform. Air is periodically removed from the thickness of the mixture. To do this, the material is pierced with a rod. At the last stage, the surface of the workpieces is leveled, for which a metal strip is used - it helps to remove unevenness.

Pros, cons and limitations of use

Arbolite has been used in construction for a long time and successfully. During this time, all the advantages and disadvantages of the material, as well as ways to combat the latter, were fully identified. The only serious limitation on use is the use of wood concrete in multi-story construction - a house higher than three floors cannot be built from it.

In other cases, the advisability of its use is considered depending on the advantages and disadvantages of the material.

What is good about wood concrete?

This building material is quite simple to manufacture - it can even be done manually, for which a simple concrete mixer is enough. In addition, there are quite a few other advantages:

• Good resistance to mechanical stress. At the same time, the block can be sawed with a regular hacksaw to give the desired shape.
• Wood concrete is a lightweight material, so a house built from it does not require a powerful foundation.
• The manufacturing technology makes the material unattractive to termites and similar insects, and also makes the walls resistant to fungi and mold.
• Arbolite blocks are larger and lighter than their analogues made from cinder block, foam or aerated concrete. The dimensions make it possible to reduce the number of operations (bring and lay), which will speed up the overall pace of construction. If a cinder block weighs 8 kg, then an equal-sized wood concrete material weighs about 4 - less effort will be spent on transporting it. At the same time, the strength of wood concrete is approximately the same.

• Arbolite walls lend themselves well to drilling - you can hammer nails into them or tighten screws, where they are held in place like in wooden boards.
• An excellent heat-insulating material - sometimes used as insulation.
• Wood concrete does not burn. With prolonged exposure to high temperatures, it may begin to smolder, but little smoke will be released.
• Unlike brittle concrete, wood concrete blocks can withstand much greater tensile loads, so cracks in walls made of this material can only appear as a result of a gross violation of construction technology.
• Arbolite does not contain harmful chemical compounds, which makes it an environmentally friendly material.

• The vapor permeability values ​​of the material are similar to those of wooden products - the walls are “breathable” and do not require additional ventilation.
• Durability. According to technical characteristics, the frost resistance of wood concrete is up to 50 freezing cycles. If we take into account that freezing can damage only wet material, with proper and timely treatment of walls with plaster, their service life will be much longer than 50 years.

Disadvantages of the material

Production technology involves a large amount of manual labor - for example, automation is not capable of stripping and is left to mixing the components. The rest, if possible, is done in semi-automatic mode, but if there are less than 3-4 people servicing the wood concrete production machine, then the speed of work will drop significantly. The manufacturing material itself is inexpensive, but a significant part of the cost is wages for workers.

“Breathing” walls at the same time imply a high level of hygroscopicity of the material. If the blocks become saturated with moisture, especially before frost, their service life will sharply decrease. Plastering the walls allows you to cope with this problem.

In the autumn-winter period, blocks stored in a warehouse cannot be covered with plaster, so they must be protected from getting wet.

One of the disadvantages of the material can be seen with the eyes - this is its appearance - it looks like chipboard, but the color is like a concrete coating. To solve this problem, the walls are plastered or covered with siding. Some manufacturers offer wood concrete with one side already plastered, but there is little point in this, since the walls still need to be plastered, if only to prevent them from getting wet.

In artisanal conditions, which small manufacturers often do, it is difficult to obtain the exact geometry of the blocks. This means that the seams between them will be thick, and this, in addition to excess consumption of cement, also creates additional “cold bridges”.

Composition of “wood” concrete arbolite: organic and inorganic parts

Wood concrete is a very unusual type of concrete, where the main filler is waste from the wood processing industry - shavings, pine needles, etc. It is the composition that provides the unusual properties of this building material. So, today let's talk about the composition for the production of wood concrete and blocks from it according to GOST, proportions, recipe and production technology.

Recipe

There are a lot of recipes for making monolithic wood concrete with your own hands at home. In some recipes, timber is prepared and processed, in others a chemical element is mixed in. According to one method, the crushed wood is soaked in lime (80 kilograms of lime per 1 m3 of wood) and squeezed out. Then sprinkle quicklime powder (80 kilograms) on top, stir, level, dry and add to the composition. This gets rid of wood sucrose, which affects the quality of monolithic wood concrete.

Fiddling with crushed wood, especially in such volumes, is quite a time-consuming activity that requires space. In this regard, a quick way to produce wood concrete will be the use of calcium chloride or aluminum sulfate. And then the crushed grain does not need to be processed, but it will be better if you let it sit outside, in the rain and sun, for a couple of months. If possible, it should be soaked in water and dried the day before preparing the solution. Soaking and curing is simply the usual preparation of wood pulp to remove some of the sugar.

If, when adding calcium chloride 5% of the total mass of the cementing substance, a white salt coating appears on the hardened material (efflorescence, efflorescence), then the proportion of the content of the chemical element must be reduced. There is no exact ratio of the chemical component for monolithic wood concrete. It always needs to be installed independently in accordance with the quality of the cement and crushed material used.

Someone does not want to mess with the selection of the calcium chloride ratio. And, to prevent efflorescence from appearing, sodium silicate is added to the mixture. For example, 2% calcium chloride and 3% sodium silicate by weight of cement. But sodium silicate is quite expensive, so for most it is cheaper to do a couple of test batches and find out the calcium chloride ratio. To impart various additional properties to wood concrete, it is practiced to use slaked and quicklime, liquid glass, aluminum sulfate, and calcium.

See the following video about the pros and cons of wood concrete.

conclusions

In a comparison of block and monolithic wood concrete, the characteristics of the materials are visible: construction from monolithic material is cheaper due to reduced transportation costs and the amount of cement, but it requires a lot of labor time for preparing wood chips and pouring the monolith.

At the same time, houses made from both types of wood concrete require enhanced protection from atmospheric moisture and reinforcement in the case of building a 2-story house. Both construction methods have the right to exist, the choice is up to the homeowner.

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What it is?

Wood concrete is one of the varieties of lightweight concrete, the structure of which includes wood chips (crushed wood), high-grade cement, chemical additives and water. The need for chemical additives in the structure of wood concrete blocks is due to the fact that in the organic component it is necessary to level out the residual polysaccharide in order to increase the bond of crushed material and cement, as well as to further improve the characteristics of the finished building material, such as cellularity, forced hardening, the ability to kill bacteria, etc. The economic effect of using this type of waste has been confirmed by leading companies producing wood concrete. The rationalism of wood consumption also plays a significant role in this issue.

The main component for the production of wood concrete is wood waste from furniture and carpentry factories, which results in crushed wood of the required size. The technological characteristics of wood concrete depend on chemical additives. Along with calcium chloride, it can be liquid glass, aluminum sulfate, slaked lime; they make it possible to improve arbolic blocks and add additional characteristics to them.

The technical parameters of wood concrete, the structure of which contains an additive (chips from waste), are as follows.

• Average density. 400-850 kg/m3.
• Pressure resistance. 0.5-1.0 MPa.
• Fracture resistance. 0.7-1.0 MPa.
• Thermal conductivity of wood concrete. 0.008-0.17 W/ (m*s).
• Frost resistance. 25-50 cycles.
• Moisture absorption: 40-85%.
• Squeezing. 0.4-0.5%.
• Degree of biostability. V group.
• Fire resistance. 0.75-1.50 hours.
• Noise absorption. 0.17-0.80 126-2000 Hz.

Practical experience

If a master intends to make wood concrete blocks on his own, he must understand that the optimal cement consumption is determined experimentally . It is recommended to make three types of samples with different flow rates.

The first - with a standard binder content, the second and third - respectively 15.0% less and more than accepted, with a correction of water consumption by 5.0% in both directions. The content of the aggregate remains unchanged.

Wood concrete, composition, video proportions - approximate calculation

Suppose it is necessary to make a structural and thermal insulation block B1.50, with a density of 650 kg/m³.

Materials that are available:

• filler – crushed coniferous wood (composition complies with the standard), average dry density 120 kg/m³, moisture content by weight 50%;
• binder – M400 Portland cement.

Sequencing:

• Portland cement consumption – 330 kg/m³;
• crushed consumption – 220 kg/m³ – taking into account humidity, consumption can increase to 330 kg/m³;
• liquid consumption – 390 l;
• chemical additive – 8 kg/m³, 10% concentration. The finished solution (at a density of 1.084) contains salt 0.108 kg/l. To introduce into the mixture you will need 8/0.108 = 74.07 liters - this amount of salt solution contains 72.3 liters of water (1.084 * 74.07-8).

Adjusting water flow:

• taking into account the chemical additive solution and water contained in the crushed grain, the volume is calculated as follows: 390.0 – 72.3 = 217.7 liters.

To implement an experimental batch, it is recommended to calculate the material consumption per 15 liters:

• cement = 380*15/1000 = 5.7 kg;
• crushed = 220*15/1000 = 3.3 kg;
• water = 390*15/1000 = 5.85 l;
• chemical additive = 8*15/1000 = 0.12 kg.

All trial batches are carried out in a similar manner.

Material characteristics

Arbolite blocks have several components - a base, binders and additives to improve the quality of the material. The new composite material has the advantages of all its components, and also allows you to get rid of their disadvantages.

Block and monolithic material first appeared in the thirties in Holland. Over the next twenty years, wood concrete spread throughout Europe, America and came to the Soviet Union, where it was widely used in the construction and finishing of finished structures.

Industrial material consists of the following components:

• wood chips;
• cement;
• water;
• fillers.

The block recipe uses pine chips, woody stems, cotton or rice straw. Cement plays the role of the main binding component; the density and strength of wood concrete depends on it. Fillers are needed to neutralize wood sugars, which cause rot and attract insects. Aluminum sulfate, calcium nitrate or liquid glass are used in production mixtures. Water dissolves all fillers and catalyzes the cement reaction. When produced at special enterprises, the recipe uses 500 ml of liquid glass, 25 kg of cement, 40 liters of water and 130 liters of wood chips.

This is useful: how to make wood concrete blocks with your own hands.

In this video you will learn how to mix wood concrete:

Main characteristics:

• density - 600-800 kg per cubic meter;
• thermal conductivity - 0.10-0.17 W/(m*s);
• frost resistance - a wet cube can be frozen 30-50 times;
• water absorption - 50-85%;
• biostability - fifth group;
• shrinkage - 0.5%;
• sound insulation - 0.15% transmitted sounds up to 2000 Hz;
• fire resistance - 60-90 minutes before destruction in a flame.

In this video you will learn about the composition of wood concrete:

Types of wood concrete concrete

The building material is produced in two modifications:

• structural , strength grade B 1.5…3.5 and density 550…850 kg/m3;
• thermal insulation , strength grade B 0.35…1.0, density up to 500 kg/m3.

The strength grade depends on the amount of wood chips in the mixture and the grade of cement.

Monolithic structures are made using removable or permanent formwork.

Prefabricated formwork

Estimate, cost of floors for sawdust concrete soil

Here I didn’t consider everything as meticulously as with the roof of my house, where in the estimate you can see everything from start to finish, down to every screw and nail. I have already mentioned the cost of basic materials in the text of the article. And based on the final amount, I will say that I had a budget, according to my calculation, 25,000 rubles . on the floors, but even there are still 2 tr left. (i.e. this is all together with delivery). Floor area - 31.4 sq. m. (minus the foundation tape, it protrudes by 30 cm.)