Wood chips in concrete blocks. Arbolite blocks: pros and cons, DIY production. Production of wood concrete blocks

Cement-sawdust materials are a practical alternative for foam and aerated concrete, as well as brick, wood and other materials in construction low-rise buildings and baths. The material is different good properties and at the same time pleasantly pleases with its accessibility.

In addition, you can not only purchase it, but also make it yourself at home without purchasing expensive equipment, and if the main component is present - sawdust or wood chips, then this makes wood-cement products even more profitable.

Advantages and disadvantages

Arbolite blocks– the material is not new, but until recently it was not widely used, which is more than surprising, given its excellent performance characteristics.

Positive features include the following properties:

  • Excellent thermal insulation performance. Houses made of sawdust concrete, like a thermos, keep warm in winter and cool in summer. The use of wood concrete eliminates the need for thermal insulation of walls, which, accordingly, saves money on construction.
  • Absolute naturalness. All components of building materials are of natural origin. They are non-toxic and do not emit harmful microparticles that cause allergies and diseases.
  • Strength. In the segment of porous materials, wood concrete has good structural strength, which allows it to be used as a material for load-bearing structures buildings not exceeding three floors in height.

  • Non-flammability. In the manufacture of concrete particle blocks, synthetic additives are used to ensure good fire resistance of the material. It can withstand temperatures of approximately 1200° C for 2 hours without igniting.
  • High vapor permeability. The porous structure allows fresh air to freely penetrate into the house, which creates a comfortable, unstuffy atmosphere. In addition, vapor permeability allows moisture trapped in the wall to evaporate, thereby preventing its accumulation and dampening of the walls.
  • Temperature resistance. The material is resistant to freezing and thawing cycles and does not collapse during changes in season, when the frozen wall begins to heat up.
  • Acceptable price. Arbolite blocks are somewhat more expensive than aerated concrete, but they can be used as a material for load-bearing structures of low-rise buildings and without resorting to bricks and similar materials, which reduces the cost of the structure as a whole.

  • High noise insulation. The porosity of the material provides significant sound absorption, reducing the level of both incoming and outgoing noise.
  • Easy processing. The material can easily be cut, drilled and other processing methods without cracking or chipping, and maintains structural integrity under mechanical stress.
  • Use of recycled materials. The main part of the mass of wood-cement materials is shavings or chips, which are waste from the woodworking industry. Even if you do not have your own source of raw materials, it can be purchased at a low price and used to create building materials, which will reduce its already low price.
  • Easy to use. The blocks are quite voluminous and at the same time light; walls are created quickly and without significant expenditure of physical strength.
  • Durability. Provided that wood concrete blocks are protected from moisture, they will serve for many decades without destruction from drying out, corrosion and other sluggish processes.

In addition to the positive aspects, wood concrete blocks have some disadvantages:

  • Long production. After pouring into the mold, the material must harden for three months before being used in construction.
  • Weak moisture resistance, high moisture absorption. Most wood-cement blocks are afraid of moisture and at the same time actively absorb it. Protection from water is the main task for those who want to use cement-bonded particle board materials in construction.
  • Limited wood species as raw materials.

Application technology

During construction outer wall buildings using wood concrete, to prevent moisture penetration, a base made of brick or concrete is installed with a height of at least half a meter from the blind area. For the same purpose, the eaves fly beyond façade walls must be at least half a meter from mandatory installation storm and melt water drainage systems.

  • The seams between the blocks should have a thickness of 10-15 mm.
  • Arbolite blocks are often used for laying only the inner layer for the purpose of insulation.

  • When using cement-bonded particle blocks as a material for doors and window lintels mandatory reinforcement is required.
  • Density and class of blocks by brand:
    • M5– 400-500 kg/cu.m. m, B0.35;
    • M10– 450-500 kg/cubic. m, B0.75;
    • M15– 500 kg/cu.m. m, B1;
    • M25– 500-700 kg/cu.m. m, B2;
    • M50– 700-800 kg/cu.m. m, B3.5.

Arbolite blocks are eaten by rodents, so you need to reinforce the wall with mesh in the area where pests are accessible or combine the masonry with another material.

Compound

The main component of the building material is sand, as well as cement and shavings (chips). Cement affects strength, workability and some other performance properties. The grade of cement used to create the blocks must be at least M400.

The increased sawdust content enhances the noise-absorbing and heat-insulating properties of wood concrete blocks. Wood chips must be thoroughly dried before use..

As the proportion of sand increases, strength increases, but the thermal insulation of the material decreases. Also during production, chemical additives are used to enhance various qualities.

For example, it is almost mandatory to use a component that increases the fire resistance of the material. In addition, a substance that repels rodents and other pests can be used.

Types of wood-cement materials

Depending on the added wood filler, wood-cement materials of various sizes and structures are obtained. The type of binder also influences the result.

Among the many options, the following widely used types can be identified:

  • wood concrete;
  • fiberboard;
  • sawdust concrete;
  • cement bonded particle board;
  • xylolite.

Arbolit

This is a material with a high content of wood chips, water, a binder component - mainly Portland cement - and chemical additives for various purposes. Wood industry waste from deciduous and coniferous trees is used for production.. An alternative can be flax or hemp brome, chaffed straw, chopped cotton stalks and similar raw materials.

It is divided into two main classes: construction and thermal insulation. In the second, the percentage of wood component is increased, but the strength is reduced.

Wood concrete is used to create products for any purpose:

  • blocks for forcing external and interior walls;
  • floor slabs;
  • floors and coatings;
  • large wall panels.

Fibrolite

This building material is produced in the form of slabs based on waste chips and a binder. According to the parameters, the raw material for wood filler is shavings 35 cm or more long and 5 to 10 cm wide, ground into wool.

On next stage mineralization of the wood filler with potassium chloride occurs, it is moistened with water in a certain proportion and mixed cement mortar, and then pressed into slabs under a pressure of 0.4 MPa. Then heat treatment and drying of the finished products occurs.

The material comes in two types: heat-insulating and insulating-structural.

The characteristic properties of this material are:

  • strong roughness– determines its high adhesive properties with finishing materials;
  • fire safety– the material does not burn with an open flame;
  • high thermal insulation performance– thermal conductivity is only 0.08-0.1 W/sq. m;
  • ease of processing– cutting, drilling, driving in dowels and nails is carried out without any problems;
  • moisture absorption in the range from 35 to 45%;
  • vulnerable to fungal mold at humidity above 35%.

Sawdust concrete

This material is similar to wood concrete, but it does not have such strict criteria for wood filler. The material is so called due to its composition - it consists of sand, concrete and sawdust of different fractions. In addition, this material may contain lime and clay, and the percentage of sand may exceed that of wood concrete. Thus, at the same density, the strength of sawdust concrete is less.

As a result, the weight of the supporting structure made of sawdust concrete will be greater than that of wood concrete with the same structural strength class - M. The thermal insulating properties of sawdust concrete are also inferior to wood concrete.

The main advantage is the price of the material - consumer reviews also speak about this, which, in the absence of special requirements, makes its use more profitable.

In addition, the strength of sawdust concrete is inferior to wood concrete, but significantly exceeds the strength of other porous block materials of non-wood origin.

Cement particle boards

This material is a widespread type, made from a wood-shaving mixture mixed with water, cement and mineral additives, followed by dosing, molding, pressing and heat treatment.

TO characteristic features materials include:

  • frost resistance;
  • non-flammability;
  • biological inertia.

This material is used in prefabricated housing construction. Area of ​​application: façade and interior work.

What makes the boards unique from other wood-based materials is their high moisture resistance. The disadvantages of this material include relatively heavy weight– 1.4 t/cub. m, which makes it difficult to work with them above the first floor. The second disadvantage is weak elasticity, which is why when the slab is slightly bent, it breaks. On the other hand, the plates are resistant to longitudinal deformation and are used to strengthen the frame.

Xylolite

Refers to sand materials based on magnesium binder and wood waste: sawdust and flour. The composition contains finely dispersed minerals: talc, marble flour and other ingredients, as well as alkaline pigments. During the production process it is used high pressure(10 MPa) and a temperature of about 90 ° C, which provides special strength during hardening.

Such slabs are used mainly for making floors.

The characteristic features of xylolite include:

  • high compressive strength depending on the specific type (from 5 to 50 MPa);
  • excellent resistance to impact loads - the material does not chip, but is dented;
  • high noise and heat insulation properties;
  • incombustible;
  • frost-resistant;
  • moisture resistant.

To learn how to make blocks from cement and sawdust with your own hands, see the following video.

Arbolite or cement-bonded particle blocks– material for the construction of buildings: it is lightweight concrete, which contains mineral binders and fillers (sawmill and woodworking waste, or organic cellulose raw materials), as well as water.

Arbolite combines the qualities cement stone and wood, it has excellent characteristics - it is not subject to rotting, fire-resistant and easy to use, suitable for individual housing construction up to 3 floors inclusive. Wood concrete blocks consist of 80–85% wood filler (chips, crushed or shavings from 2 to 25 mm long, 5 mm thick) and high-quality cement, not less than PC500.

Production technology

Today, in the manufacture of (CSB, DSP), mainly pine chips are used, but according to GOST 19222–84, the use of other wood processing waste (from deciduous and softwood) is also allowed. However, the best quality wood concrete comes out of pine or spruce shavings, since these species contain the least amount of organic component (sucrose) that needs to be neutralized.

Wood chips for CSB are subject to drying and mineralization of the surface with a solution of chemical components that eliminate sucrose, which helps prevent rotting and fungal damage to the wood during operation. When using any other additives and materials (sand, plasticizers, hardeners), the product cannot be considered a real wood concrete.

The production of wood concrete has been put on the conveyor belt in many cities of Russia, but you can make blocks with your own hands if you strictly follow the technological process and acquire minimum set tools:

  • Special crusher.
  • Concrete mixer.
  • Forms for blocks.
  • Vibropress or vibrating table.
  • Drying chamber or space under a canopy.

Types and form of release of TsSB

According to their density, wood concrete blocks are of the following types:

1. thermal insulation or hollow (400–500 kg/m3);

2. structural (500–850 kg/m3).

IN industrial production wood concrete blocks are produced:

  • wall or standard (500x300x200 mm);
  • partition (600x300x120 mm).

Dimensions

The dimensions of blocks made of cement and shavings for the construction of external walls are 300x200x500 mm (per 1 m3> - 33 pieces), and for internal partitions you can use 120x300x600 mm, 47 pieces per m3, respectively.

Houses made of wood concrete according to their economic and operational characteristics significantly better than structures made from other materials. Thus, a house made of CSB or DSP is dry and warm, its walls are light, fire-resistant, retain heat well in winter and cool in summer, are easy to decorate, durable and cheap.

Each building material has its own advantages and disadvantages, and wood concrete is no exception; let’s look at the pros and cons of such blocks.

Advantages of wood concrete

1. 1 m2 of constructed walls made of wood concrete is 3 times lighter than structures made of expanded clay concrete and 8 times lighter than those made of brick. This makes it possible to relieve the foundation.

2. The cost of constructing a residential building from CSB is 40% less than from other materials.

3. Products made from shavings and cement stone have a porous structure, which ensures natural air circulation and optimal humidity in room.

4. Strong bond with concrete and plaster without the need for reinforcement.

5. Arbolite products, more information about which in, are excellent for sawing and cutting (you can make the most precise adjustment), drilling, chopping, holding screws and nails.

6. Exceeding the maximum permitted loads on wood concrete leads to its compression and subsequent recovery, rather than cracking, which allows you to painlessly endure shrinkage at home.

7. The tensile and bending strength of cement-bonded particle board materials (CSB and CSP) allows the use of all types of floors (wood, reinforced concrete).

Minuses

1. Limited number of storeys in the building.

2. Wood concrete is not widely used and is difficult to buy in some parts of Russia.

3. Water permeability, but this disadvantage is eliminated by plastering the walls.

4. A large number of unscrupulous manufacturers producing low-quality blocks with different compositions.

As you can see, the positive qualities of this material more than compensate for its minor disadvantages.

In terms of thermal conductivity and fire resistance, DSP and TsSB are superior to all traditional building materials. Properties of wood concrete, including cement particle boards, made it possible to use them for the construction of buildings even in Antarctica. There is a lot about him good reviews abroad, it is widely used there and is valued for its energy-saving, heat-storing and sound-proofing properties.

Given specifications blocks clearly demonstrate the combination of material qualities that make it possible to build warm and environmentally friendly two- to three-story buildings.

Reviews from home owners

“I decided to calculate the cost, and it turned out that for 1 m3 of wood concrete we need approximately 1,200 rubles worth of Portland cement (at new prices). Add in labor and other materials and additives, then the cost will reach 2,500 - 3,000. Considering that a cube of wood is around six thousand, this is not very expensive. And wood concrete performs a load-bearing and insulating function (a huge plus) and the reviews about it are good.”

Ivan Slepkov, Moscow.

“I really like the Central Construction Buildings - construction is going much faster. There is only one thing, but in order to find a bona fide manufacturer of these same blocks and cement bonded particle boards, I had to scour half the Internet and go through a lot of reviews. We were very pleased with the house; you can breathe in a house like a wooden one!”

Andrey, St. Petersburg.

"From personal experience I will say that next time I will under no circumstances get involved with wood concrete, and I also do not recommend it to anyone. The material is undoubtedly of good quality, simply ideal, but, unfortunately, as often happens, the manufacturing is absolutely disgusting.”

Elina, Kazan.

“When I come to visit a friend, he has a house from the Central Bank, I feel so envy that I don’t have something like that. I honestly don’t know the downsides of wood-concrete, it’s good for everyone!”

Mikhail Plotnikov, Yekaterinburg.

Cost of cement bonded products

You can buy wood concrete from manufacturers or in construction supermarkets. Prices for this material are set depending on the composition of the product and its size. Wood concrete is usually sold on the market in cubic meters or sheets (DSP). Thus, the price of one block of the 400x200x200 mm format will be 68 rubles, and the cost of 1 m3 will be 4,300 rubles, respectively, excluding transportation.

Namestandardstructuralseptalhollow
Price, rub/m33700 3700 4300 4600 4500 5000 3200
Number of blocks per m3/piece33 25 14 23 21 47 27
Length500 500 600 500 600 600 500
Width300 400 400 250 400 300 300
Height200 200 300 350 200 120 250

Wood concrete, otherwise known as wood concrete, has unique thermal insulation properties, thanks to which it is successfully used in the construction of houses.

This material should not be confused with sawdust concrete, the production of which uses sawdust and sand. In the case of obtaining the material in question, wood chips for wood concrete are made from wood waste, since this is the most cost-effective due to the low cost and availability of metalwork waste, the block itself can be produced with your own hands.

Wood concrete composition

This material is endowed with unique thermal conductivity properties due to its components. Like all concrete blocks, it contains a binder in the form of cement; in most cases, Portland cement grade M400 or M500 is used in the production of this material.

The main filler, occupying almost 90% of the volume of the material, is wood chips.

Chemical additives can account for 2-4% of the total mass of the concrete block. They increase its strength and, when combined, form compounds with the sugars present in the wood.

In some cases, sand and slaked lime are added to it.

Used for breeding construction staff water is poured into the solution warm, its temperature should be +15 0 C. If it is less than this value, then the setting speed cement composition will be lower.

The exact proportions of the components of wood concrete depend on the chosen brand.

Chips used for wood concrete

This wood material In the production of wood concrete, several types of loka can be used. But not any chips can be suitable for this process, but only those that correspond to GOST in geometry and dimensions.

Wood chips must be needle-shaped and fit into the following dimensions:

  • length 15-25 mm;
  • thickness 2-3 mm;
  • width 10-12 mm.

To prepare it yourself, you need to use special chipping machines, which in a short time are capable of processing various tree branches and tops, waste from the wood processing industry and slabs into chips.

Coniferous trees are most often used to make wood chips: pine, spruce, fir; birch and aspen have also proven themselves, but beech and larch should not be used.

Sometimes crushed tree bark and needles are used as wood chips, but they are mixed together with the main filler. Before use, the selected wood material must be antiseptic treatment

, it is also freed from water-soluble substances, which can reduce some of its performance characteristics. If you have nowhere to get it required tree

, then you can use hemp or flax bonfires, rice straw, or cotton stalks. Before using flax seeds, you need to soak them in milk for two days or leave them in the air for a long time, about 4 months. After production or purchase, wood chips must be sifted and cleaned of dirt and bark. Then it needs to be dried and treated with silicate glue or calcium chloride to make it plastic. To reduce drying time you need to apply liquid glass, But

ready-made blocks

in this case they turn out to be more fragile.

Purchase of wood chips and wood for it

Raw materials for the production of wood chips can be found in forestry and an agreement on the purchase of a certain volume will be agreed upon; the cost of transporting it will fall on the shoulders of the buyer, and if you purchase wood from private companies that are intermediaries, then delivery will be included in the cost of the material.

The wood chips themselves can be purchased from private companies that have purchased the appropriate equipment and produce them for sale. Or you can purchase the necessary chipping machine and make wood chips with your own hands; it will be much more economical. Do-it-yourself production of wood chips for wood concrete It is most profitable to build a house from material made independently from start to finish. To do this you need to purchase

necessary materials

  • and equipment. Chips can be made from wood, which is purchased “for future use” and stored in a place protected from weather precipitation, as well as from plumbing and forestry waste.
  • The most important attribute for obtaining wood chips is chipping machines, also called wood chippers. They come in several types, and each one works slightly differently. You can purchase machines:
  • hammer;

The final choice will depend on production volumes, because you can set up the process of producing wood chips with your own hands, not only for your own needs, but also for sale; this type of activity will quickly pay for itself, since such material is in great demand not only in construction, but also for heating homes , and even for landscape design.

Before purchasing any of the above types of devices, you need to choose a location for its installation, consider free access to the loading window of the device, and also how the wood chips flying out of the device with enormous force will be collected. Many people miss this moment, and small material scatters throughout the production site. Some people set aside a small hangar for it and, after stopping the machine, collect the resulting material with a shovel.

Hammer crushing machines

Such crushers can be single-shaft or double-shaft; for home production, the first type is sufficient. This is a rotary device that contains hammers and chippers in its core. The unit has a special loading hopper. You need to put thin logs prepared in advance into it, it is better to make them long or purchase them, this will secure the process, otherwise if you handle a short piece awkwardly, there is a high risk of injury.

When wood enters the device, it passes between the hammers and separating plates, is split by impacts, and then sifted through the grate holes into the outlet compartment. The size of the chips will depend on the size of the sieve cells; its maximum size usually does not exceed 6 mm.

Disc chippers

Some of their models have adjustable knives, due to which you can change the size of the resulting chips.

They are designed for processing any forest, including round timber, the timber of which must be loaded into a separate window, where it, falling on the knives, is pulled deep into the device and splits. Max diameter log is 10 cm.

Drum chippers

You can recycle not only wood, but also waste furniture production, sawmills. Models of such chip cutters are equipped with a large loading hopper into which branches and logs need to be fed, they are self-retracted into the device, and after passing through the drum with double-sided sharpening knives located on it, they receive chips required sizes. Small models have one wheel to make the device easier to transport.

To simplify the process of producing wood chips with your own hands, you can make an entire line that will consist of a wood chip cutter, a chain conveyor and a debarking drum.

The operating principle of such a system is simple:

  1. raw materials are loaded into the machine to produce chips;
  2. at the exit, the finished chips enter the conveyor;
  3. the device delivers material to the debarking drum;
  4. After achieving the required cleanliness, the contents of the drum are unloaded onto a chain conveyor, which delivers the chips to the storage tank.

Human participation in this process is minimal.

The process of obtaining wood chips for making wood concrete is not complicated, if you first allocate a place for installing equipment and select it for a specially designated place. The material is loaded manually, to protect yourself it is better to use long workpieces, and if you use a large bunker, you can load smaller raw materials using a shovel.

Sawdust concrete and wood concrete blocks are lightweight construction material having good thermal insulation characteristics. They are used for the construction of private houses, outbuildings and fencing. Sawdust concrete and wood concrete can be purchased ready-made or made with your own hands. For manufacturing, you will need the same components as for standard concrete blocks, but with the addition of sawdust or wood chips. They can be both structural and thermal insulating.

For sawdust concrete blocks you will need cement, sawdust, sand, quicklime and water. Portland cement is taken at a grade no lower than M300. It is better to use sawdust from coniferous trees, as they are less susceptible to rotting. If they are old or obtained from other wood, then they need to be prepared. Treat with antiseptic agents, for example, calcium chloride solution, and dry.

The density of sawdust and cement blocks depends on the proportions of the components. The more Portland cement, the stronger material, but the worse the thermal insulation properties. This increases resistance to low temperatures, moisture and reduces the likelihood of corrosion in reinforced blocks.

If you add more sawdust, the wood concrete blocks will retain heat better, but it cannot be used for the construction of load-bearing structures. Due to the small amount of cement in the composition, it will have weak strength. Therefore, it can only be used as thermal insulation of a finished structure. At the same time, the masonry does not require the construction of an additional foundation, since it is light in weight.

Blocks made from a mixture of cement and sawdust are used for the construction of load-bearing and internal walls of buildings, enclosing structures, for the reconstruction of already built structures, as well as for insulating houses and basements.

Positive and negative characteristics

Advantages of block material made from sawdust (they are confirmed by numerous reviews given in the material about):

  • easy to process - sawdust concrete can be cut with a regular hacksaw and drilled, just like aerated concrete or foam concrete;
  • has good adhesion characteristics – during processing adhesive compositions the finishing coating is securely attached to it;
  • good thermal insulation properties;
  • low flammable - with the right technology manufactured sawdust concrete can withstand direct exposure to fire for about three hours (if the amount of sawdust does not exceed 50% of the total volume);
  • environmentally friendly;
  • soundproofs;
  • simple masonry;
  • long service life.

Sawdust concrete acquires the property of fire resistance as a result of enveloping sawdust cement-sand mixture. Compared to concrete with polystyrene foam granules, blocks made from sawdust are more fireproof.

The disadvantages include long time strength gain. After production building blocks 20 cm thick is left for 3 months to completely harden. Only after this period has passed can you begin laying them. Sawdust concrete has poor resistance to water. Therefore, after the construction of the house, a vapor barrier should be installed to protect it both from the inside and outside of the building.

How to do it yourself?

There are many technologies for making blocks from sawdust. Not only cement, but also gypsum or clay can be selected as a binder component. But if block material will be used for the construction of loaded structures (walls), then Portland cement is taken. To prepare the solution yourself, it is recommended to use a concrete mixer, since a completely homogeneous consistency is required.

According to the technology established in accordance with GOST, in order to make high-quality blocks, you will need to mix the components in the following proportions - 1 part cement, 1 sawdust, 3 sand and 50% of the volume of binder water. Calcium chloride is taken 40 times less quantity cement powder. That is, for 20 kg of Portland cement M400 you will need 20 kg of sawdust, 59-60 kg of sand and 10 liters of water. Additionally, 0.5 kg of calcium chloride is added. In percentage terms, sawdust should account for almost 55% of the volume of the entire solution, sand - 26%, cement - about 12%, water - 7%.

Sand is used in medium or coarse fraction. In this case, about 10% fine fraction is added. Only clean water is poured. It is best to use drinking water or rain water, the main thing is that it is free of impurities and dirt.

To make the blocks yourself, you will need molds into which the mixture will be placed. It is recommended to make them collapsible to make it easier to take out ready material. It can be built from boards 20 mm thick. They are covered inside with sheets of steel so that moisture from the solution is not absorbed into wooden case. In addition, thanks to the metal, the block material can be easily separated from the mold.

When assembling a box for sawdust concrete or wood concrete blocks, you should take into account that after drying they decrease in size. Therefore, the mold must be made 10% larger than the required size of the material. If there are blocks with voids, for example, round ones, then roofing felt, rolled into a tube, is placed in the box in advance.

Manufacturing technology: sawdust is sifted through a sieve and mixed with Portland cement and sand. Water is gradually poured in. To check the quality, the solution is squeezed in a fist. It should be crumpled into a lump, no water should leak out. If drops are noticeable, it means it was mixed incorrectly. After preparation, the composition must be dissolved within one and a half hours. The mixture is placed in a mold. Every 20 cm it is compacted to compact and remove air. After filling, everything is left for 4 days. After which it can be disassembled and the block building material can be stored in a dry and ventilated area for further hardening.

Peculiarities

For arbolite blocks, not sawdust with sand is used, but only wood chips; cement and various additives are also needed that improve other characteristics. Compared to sawdust concrete, this material has even better thermal insulation properties. It is also lightweight, frost-resistant and non-flammable. The blocks are environmentally friendly, they are easy to cut and process.

For self-made Such blocks will need forms. The solution is mixed in a concrete mixer. To make wood concrete blocks, the components are mixed in the following proportions: 3 parts cement, 3 parts wood chips and 4 parts water. First, wood chips are poured into the concrete mixer and water is poured in (not all at once, only until it becomes semi-liquid). Liquid glass is added (1% of the total volume). After the consistency has become homogeneous, Portland cement M400 is poured in and the remaining water is added.

Once the solution is thoroughly mixed, it is placed in a mold for wood concrete blocks. The mixture is tamped every 15-20 cm. After a day, if the material has hardened, it is removed from the molds and left to gain strength. After 2-3 weeks the blocks can be used.

Wood concrete, otherwise known as arbolite blocks, have such attractive characteristics that the desire of folk craftsmen to make them with their own hands is quite understandable. But is this building material as good as the advertising advertises, and is it possible to set up its production at home? To clarify the situation, we propose to consider in detail what wood concrete is, study its properties, manufacturing technology and reviews from developers.

What is wood concrete

This building material belongs to lightweight concrete with a coarse-cell structure and wood filler. It is produced in the form of blocks ( standard size– 50 x 30 x 20 cm), slabs with reinforcement frame and liquid mixtures poured into the formwork during the construction process. According to GOST, the composition of wood concrete should be as follows:

  • wood chips of strictly standardized sizes;
  • chemicals - alumina sulfate, lime, liquid glass, calcium chloride;
  • cement M400-500;
  • water.

Note. Chemically active additives are designed to neutralize the effects organic matter(sugars) contained in wood, on the adhesion of cement with filler.

To obtain wood concrete of standard strength, the length of the chips in the solution should not exceed 25 mm, and the width should be in the range from 5 to 10 mm with a thickness of up to 5 mm. To prepare wood concrete, you cannot use sawdust, shavings and other organic matter - straw or reeds. By the way, sawdust concrete is also a radically different material with excellent properties.

Specifications

The wood concrete blocks and reinforced panels produced at the plant are divided into 2 groups - structural and thermal insulation. The first ones have a density of 550-850 kg/m³ and are used for construction load-bearing walls. The latter, with a density of 300-500 kg/m³, are suitable only for insulating finished structures, since they do not have the required bearing capacity. An essential parameter of wood concrete - thermal conductivity - also increases with specific gravity, which is reflected in the diagram:

The remaining characteristics of wood concrete look like this:

  1. Compressive strength depends on density and corresponds to concrete grades from M5 to M50. The elastic modulus is about 2000 MPa, and the bending strength is up to 1 MPa. This means that monolithic blocks do not crack under heavy loads and, after compression, tend to return to their original shape.
  2. Water absorption of building materials is up to 85%. In practice, a stream of water can saturate wall panel through, but then drains quite quickly, after which the wood concrete dries successfully.
  3. In terms of resistance to fire, the material belongs to group G1 - low-flammability. It also ignites very reluctantly.
  4. Monolithic and hollow wood concrete products transmit steam equally well, which helps remove excess moisture from the building through the outer walls.

Concerning soundproofing properties, then wood concrete absorbs noise much better traditional materials– brick, wood and aerated concrete.

Production technology

In factory conditions technological process The manufacture of wood concrete products proceeds as follows:

  1. Wood processing waste is crushed to the right size in a crusher and cleared of bark and leaves, whose content in the raw material should not exceed 10%.
  2. Water is mixed with chemical components in the required proportions, depending on the type of wood. For example, for larch it is necessary to double large quantity mineralizers per cubic volume than for spruce and pine.
  3. The chips are sent to a forced-action concrete mixer, where they are mixed with prepared water heated to a temperature of 15 °C.
  4. M400 cement is added to the mixture and mixed for 20 minutes, after which it is poured into molds. Laying is done manually or using a vibropress.
  5. The formwork is removed from the products immediately after molding, and then they are sent for drying.

Reference. Some manufacturers practice cutting blocks on a special machine in order to give them a clear geometric shape.

Note that when molding arbolite products, the raw material is not subjected to pressing, but only vibration. Different densities of blocks and slabs are achieved by changing the concentration and size of chips in the primary solution.

Production line for the production of wood concrete

Pros and cons of the material

By thermal insulation properties wood concrete is comparable to other modern building materials, as shown in the following diagram:

In addition to low thermal conductivity, wood concrete has other advantages. They are as follows:

  • light weight, facilitating the reloading and installation of products;
  • thanks to good sound insulation properties, arbolite structures effectively protect premises from the penetration of external noise;
  • environmental friendliness;
  • high strength and elasticity, preventing cracking from static and impact loads;
  • the cellular structure allows water vapor to penetrate freely, that is, the material “breathes”;
  • The porous surface of the blocks and the composition of the mixture make it possible to use any types of external and internal cladding.

In addition, it is worth noting the ease of processing wood concrete with hand and mechanical saws, which is important when constructing walls and trimming elements. And the last one positive feature: in wood concrete products without voids (in the form of a monolith), nails, ordinary dowels and self-tapping screws hold well, and this reduces the cost of fastening various interior items and installing shelves compared to foam blocks and aerated concrete.

Now about the disadvantages, of which wood concrete also has many:

  1. Wood concrete structures need protection from moisture from outside, therefore they must be plastered or sheathed with waterproof materials with a ventilated gap.
  2. Due to the unclear geometry of the blocks, the consumption of plaster during finishing work increases;
  3. IN trading network Many low-quality products are sold that do not comply with GOST. Unscrupulous manufacturers often do not comply with the requirements for chip sizes and pour everything into the solution because they do not have calibration equipment.

The listed disadvantages are not too significant and are quite surmountable. The main negative point is the price of wood concrete. If you ask how much the same aerated concrete costs, you will find a difference of 40-60% in favor of the latter.

Self-production of wood concrete

If you have carefully studied the production technology described above, you probably understand that at home it will be possible to produce only low-density thermal insulation blocks. The maximum that can be built from them is a small one-story building with wooden floor. The reason is clear: cook a large number of Calibrated chips will not be produced due to the lack of equipment, and sorting through the waste manually is pointless.

Advice. In order for wood concrete made by yourself to have the properties of factory products, the raw materials must be freed from fine fraction(sawdust), dust and bark.

To work, you will definitely need a casting mold and a concrete mixer, preferably an auger type. Conventional gravity mixers are not very good at creating a homogeneous mixture of wood and cement. The forms are long boxes made of metal or OSB plywood with partitions for casting several elements at once. The ideal option for home production is the collapsible form shown in the drawing.

Another useful unit, indispensable in the manufacture of wood concrete products, is a homemade wood chip cutter for processing branches and other waste. An example of such an installation is shown in the video:

Now let's give a simple recipe on how to make low-density wood concrete, suitable for use for country and garden buildings:

  1. Mineralize the wood chips by soaking them in slaked lime for at least 3 hours (proportions – 1 volume of lime is diluted in 10 parts of water). Then pour the raw materials onto a sieve to drain the water.
  2. Transfer the wood chips into a concrete mixer and fill with water. The ratio is: 3 mass fractions of wood waste per 4 volumes of water. Turn on stirring and add liquid glass in the amount of 1% of the total mass of the solution in this batch.
  3. Lastly, add 4 mass fractions of M500 cement and mix until the mass becomes homogeneous and begins to mold in your hand.
  4. Lubricate the sides of the molds with waste oil and fill to the top with the raw material solution. Lightly compact the contents and let the wood concrete set for 1 day, and then remove the blocks from the formwork and dry for at least 7 days in an open area, as was done in the photo.

Removing formwork after setting

Note. The proportions of cement and wood chips are indicated by weight (in kilograms), not by volume. For water this does not matter, since 1 liter weighs 1 kg.

After a successful trial batch, wood concrete products can be improved by giving them cladding directly during the manufacturing process. The scheme is simple: the mass is placed in molds so that 3-5 cm remains to the top, and the free volume is filled plaster mortar(preferably tinted) or cut gypsum tiles imitating artificial stone.

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