Do-it-yourself wood concrete blocks. Making wood chips for wood concrete blocks Blocks with wood shavings

IN last years The housing problem has not affected rare citizens in our country. This situation hits especially hard for young families, for whom it is almost impossible to purchase their own home without taking out loans on enslaving terms.

This situation is largely due to the incredible cost of building materials, the price of which suggests that they are made exclusively using gold equipment. Is it possible to somehow correct such an unfortunate situation? Of course! The way out of the situation will be wood concrete. It’s not difficult to do it yourself, and this technology will save a lot of money.

What is this anyway?

The younger generation is unlikely to remember them, but in Soviet times Almost every second one was made from these blocks a private house. In fact, these are lungs building panels made from and cement.

To reduce the cost of production, coniferous trees are most often used, but best material obtained from hardwood chips. In the latter case, building houses from wood concrete is somewhat more expensive, but the finished buildings are of much higher quality.

According to GOST, the use of other types of organic fillers is allowed. Thus, in the southern regions it was recently widespread construction technology, in which even chopped straw was added to the blocks.

Alas, after the 60s, when the boom in panel construction, more than a hundred factories turned out to be of no use to anyone. Production was curtailed, and the good material was practically forgotten. This unfortunate misunderstanding needs to be corrected urgently!

What are the standard sizes?

To make wood concrete with your own hands, you need to have at least a basic understanding of the basic standards used in its production. The requirements of GOST 19 22284 state that to obtain the maximum quality material Only wood chips with dimensions of 40x10x5 mm should be used. The amount of needles and leaves in the fill should not be more than 5%, and the volume of bark should not be more than 10%. As mentioned above, the best wood concrete is obtained from clean and dry wood chips from deciduous trees.

Oddly enough, but some recommendations for standard sizes blocks do not exist in nature. Of course, in this matter you should focus on your own needs and capabilities. Having poured blocks a couple of meters in size, you may be faced with the impossibility of transporting them to the construction site.

During this time, the sugars contained in the wood will be completely destroyed, and ready material it will not swell in the future. Of course, it is necessary to prepare the required amount of raw materials: shavings and sawdust are used as filler, the ratio of which should be approximately 1:1 or 1:2.

We strongly recommend periodically carefully shoveling sawdust and shavings, as otherwise there will be no air access to the deep layers of the wood. And further. Make sure you have a concrete mixer in advance, since you simply won’t be able to mix the finished mixture well enough by hand.

Chemistry

To make wood concrete with your own hands, you will need not only wood shavings and sawdust. So, purchase Portland Cement 400 in advance, as well as chemical additives. These include liquid glass and aluminum sulfate. All additives should be prepared in an amount of 2-4% of the weight fraction of cement.

Let's get started

If the chips you have prepared do not exactly correspond to the standard sizes given in our article, we recommend that you immediately pass them through a chipper.

Next, we carry out the initial sorting of the material, removing various foreign impurities, large pieces of bark and pine needles from the shavings. Otherwise you won't be able to get monolithic wood concrete. You can do this with your own hands if you sift the raw materials through a sieve of the appropriate diameter. It is also important to remove excess wood dust, which can cause Negative influence on the consistency of the cement mortar.

The best option is sifting on a special screen, which gives the output the cleanest and most selected chips. To make wood concrete out of it with your own hands, after the sifting procedure, add about 20% of high-quality dried sawdust (preferably hardwood) to the primary raw material.

Having carefully shoveled the resulting mixture, soak the wood in water to which liquid glass was previously added. In order for the material to harden faster, picking up minerals from the water, it is advisable to add technical calcium chloride.

Since it is undesirable to make wood concrete with your own hands without these additives, they must be immediately purchased in the required quantity.

Molding

After this, load a portion of the composition into a concrete mixer, add water and cement, and mix thoroughly. Ideally, automatic mixers are used, from which the mixture is fed under pressure into molds, where it is pressed on automatic machines.

Since most farms will never get this, the finished composition is simply scooped out of the mixer and placed in molds. They can be made from fairly durable and high-quality wood. To ready-made blocks It was easier to get them out; it was best to cover their insides with film or linoleum.

Remember that the geometric proportions of the forms must be as correct as possible, otherwise the construction of houses made of wood concrete will be greatly complicated. To properly compact the mixture (without creating air pockets), it is better to use electric tampers. If you can’t buy it, the manual version will do just fine.

To make a normal monolithic wood concrete, you can make such a device out of wood by simply upholstering it sheet iron to ensure proper weight.

After the excess moisture has drained and the block has acquired the desired shape, it is placed under a press, having previously been wrapped in plastic film. The exposure lasts for ten days, and the optimal ambient temperature is considered to be no higher than 15 degrees Celsius.

Arbolite or cement-bonded particle blocks are a 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 of 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 (TsSB, TsSP), mainly pine chips are used, but according to GOST 19222–84, the use of other wood processing waste (from deciduous and coniferous species). However, wood concrete is actually made from pine or spruce shavings. best quality, since these rocks contain the smallest 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.

In terms of their economic and operational characteristics, houses made of wood concrete are much better than buildings made of 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 circulation air and optimal humidity in the 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. Durability cement bonded bonding materials(TsSB and TsSP) for tension and bending allows the use of all types of floors (wood, reinforced concrete).

Minuses

1. Limited number of floors 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. The 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 jealous 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.

Wood-concrete, otherwise - arbolite blocks, are so attractive in characteristics that the desire of folk craftsmen to make them with their own hands is quite understandable. But is this one so good? construction material, what does advertising say about it, 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 cage and liquid mixtures poured into 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 second, with a density of 300-500 kg/m³, are suitable only for insulation ready-made structures, because 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. It 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.

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

Production technology

Under factory conditions, the technological process for manufacturing wood concrete products proceeds as follows:

1. Wood processing waste is crushed to the required 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 right 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

In terms of thermal insulation properties, wood concrete is comparable to other modern building materials, which is reflected 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 positive feature: wood concrete products without voids (in the form of a monolith) hold nails, ordinary dowels and self-tapping screws perfectly, 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. The retail chain sells many low-quality products 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. Main negative point– 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. 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 fractions (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. Perfect option for home production - a 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 an amount of 1% of total mass 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.

Sawdust and cement blocks

Nowadays in construction you won’t surprise anyone with composite materials. What only coexisted peacefully yesterday, today, thanks to new technologies, complements each other and mixes. And the result is materials that have acquired better quality characteristics from the mixed components, and even new properties altogether. These materials also include wood-cement. We know that when mixing solutions, fillers are needed. So why shouldn’t wood waste be used as a filler? The benefit is double: the waste will be used, solving the problem of its disposal, and the concrete will become much lighter.

Types of wood-cement materials

Since wood materials of different sizes and structures can be added as filler, and the addition of cement and other components can be in different proportions, there can be several wood-cement materials. Here are the main ones:

• - wood concrete;
• - fiberboard;
• - sawdust concrete;
• - CSP (cement particle boards);
• - xylolite.

And since differences in composition lead to differences in properties, materials with different performance characteristics. This allows the use of wood-cement materials in construction quite widely.

Arbolit

This is lightweight concrete made from crushed wood, water, chemical additives and a mineral binder, most often Portland cement. Crushed wood is obtained from both deciduous and coniferous trees; it is even possible to fill the concrete with flax or hemp husks, chaffed straw, and crushed cotton stalks.

The wood concrete production technology is as follows:

1. 1. Wood waste is fed by conveyors into the chipper.
2. 2. The resulting chips are sent to a hammer crusher.
3. 3. A pneumatic conveyor feeds the resulting material into a vibrating screen, from where dust and fine crushed material go into the waste hopper, and large crushed material is sent for re-crushing.
4. 4. The required crushed fraction enters the soaking bath, and from there through the dispenser into the mixer.
5. 5. Through other different dispensers, cement, water and chemical additives are supplied to the mixer.
6. 6. The resulting mixture in molds is compacted with presses or vibratory compaction units.
7. 7. Forms with wood concrete are subjected to heat treatment and drying.

Use of wood concrete: partitions, slabs for floors, floors and coverings, large-format wall panels, wall blocks and so on.

Fibrolite

It consists of slabs made from wood chips and mineral binder. Chips longer than 35 cm and width 5-10 mm grinds into wool. Next, the technological process looks like this: the shavings are mineralized with potassium chloride, moistened and mixed with cement paste, and the slabs are pressed at 0.4 MPa. This is followed by heat treatment in curing chambers and drying.

Fiberboard is used both for the construction of walls and as a filler and insulating material in frame structures. It should be noted that when using fiberboard as wall material, it should be plastered, and where the humidity is high, it should not be used at all.

Sawdust concrete

This is lightweight concrete made from sand, Portland cement and sawdust. The technology is as follows: sawdust and small shavings are poured into the mixer, and water with mineral additives and Portland cement are also supplied there. All this is mixed, arranged into shapes and compacted. In order for sawdust concrete to harden faster, it is kept in thermal chambers for 24 hours at a temperature of 40-60°C.

Sawdust concrete is used for the production of panels and wall blocks, and is used to make clean floors.

Cement particle boards

They are the most commonly used wood-cement materials. For their productionwood shavings are used, then a cement-shaving mixture is prepared from it by mixing the shavings with water, cement and mineral additives, followed by dosing, molding, pressing and heat treatment.

Cement particle boards are frost-resistant, fire-resistant and bio-resistant. this justifies their use in prefabricated housing construction. Moreover, they can also be used for facade works and for interior decoration. They are not afraid of high humidity and have proven themselves in restoration work.

Cement particle boards also have disadvantages. High density(up to 1.4 t/m³) makes it difficult to lift slabs for cladding the top floors of houses without winches andforests They also have low bending strength and the slabs can break. At the same time, they are very resistant to longitudinal deformation, for this reason they are used to strengthen house frames.

Xylolite

It consists of magnesium binder, alkali-resistant pigments and sawdust, to which finely dispersed minerals are added: asbestos, marble flour, talc.

During production, sawdust is sifted through two sieves (the remaining on 1 sieve and sifted through the second in technological process does not participate). The binder is prepared in mixers: first magnesite is supplied, then coloring pigments, then magnesium chloride (as a hardener). This mixture is fed into another mixer, where it is mixed with sawdust for about 5 minutes.

Next, the slabs are formed under significant pressure (up to 10 MPa), at high temperatures (up to 95°C) and harden in curing chambers. Then, to ensure complete condition, the slabs dry in warehouses for two weeks. In order to increase water resistance, the slabs are impregnated with hydrophobic compounds. Most often these slabs are used for the production of floors.

-

I will answer your questions out of order, but I will answer everything.

Let's start with the film. It does not change matters whether this film will be vapor-permeable or vapor-proof. If it is vapor-permeable, then behind it (towards the street) there should be a ventilation gap. If it is not there, then the moisture remains in the first layer of reed. But technologically there is no way to create a gap there. If the film is vapor-proof, then everything is the same - the moisture remains in the first layer of reed. The fact that manufacturers put it there, but at the same time cannot clearly explain either its operation or its properties, suggests that the manufacturers, unfortunately, have not understood the operation of this design. Further. If, as you write, you install the film from the inside. Yes, this will protect the wall from vapors from the room. But this has nothing to do with moisture accumulating in the wall due to the dew point. There are two reasons for moisture in the wall. One is moisture from the room (we can protect against this with film). And the second is moisture that arises from the fact that there is a moisture condensation point (dew point) in the wall. This condensation occurs due to the difference in temperature and pressure, and if there is no vacuum in the structure, and there is no vacuum there, then this condensation will occur, even if the inside is closed with a film. Even if the wall is “wrapped with film” both outside and inside, there will still be condensation there. because there is air inside, and there is a difference in pressure and temperature. Long-winded, but I hope I explained it.

A vapor-permeable (breathable) wall or a vapor-tight (non-breathable) wall, there really is not much difference. And in terms of ventilation power too. Have you seen the numbers, the difference is within 15-20% maximum. It’s just that, to be honest, I’m surprised by the combination of non-breathable walls and clay. And, as I understand it, plastic windows, So? If a house is built with such walls for reasons of ecology, naturalness, naturalness, then something is not logical for me :-). And if clay with wood chips is just a way to make the structure cheaper, then it’s logical.

In general, regarding films (or membranes), I would not use them in this wall at all.

On the plaster wall. I have never seen this reed (straw) mat in person. If you have seen how they are plastered, then great. In fact, if they are cut and the fibers are located perpendicular to the plaster layer, then they should hold up normally. Mineral wool for plastering works. In ordinary cotton wool, the fibers are parallel to the wall, while in wool for plaster they are perpendicular, so that the mixture holds better.

By dew point. I consider the thermal conductivity for clay to be 0.1 (rounded to 0.095), for a reed mat the thermal conductivity is 0.7 (rounded to 0.065). Dew point in the second layer of reeds (counted from the outside). Therefore, even more so, you cannot cover it with any film. All moisture from there should be evaporated freely through the reed and plaster. In terms of heat, by the way, if you count clay at 0.1, then 300 mm is almost enough for Minsk. 300 mm clay + 10 mm reed, - with a margin. And 300 mm of clay + 200 mm of reed - with a large margin. But I would not remove the “extra” from the design, since these are thermal conductivity coefficients “on paper”, and in life, in my opinion, they have not yet been fully tested.

It seems to have answered everything, ask away.