Blocks with wood shavings. What are sawdust concrete blocks? Features of the construction of their wood concrete blocks

In recent years, the housing problem has not affected rare citizens in our country. This situation is especially painful for young families, for whom it is almost impossible to purchase their own housing without getting into loans on onerous terms.

In many ways, this situation is due to the incredible cost of building materials, at the price of which one can assume that they are made exclusively on 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 is not difficult to make it with your own hands, and this technology will save a lot of money.

What is it all about?

The younger generation hardly remembers them, but in Soviet times, almost every second private house was made of these blocks. In fact, they are light building panels made of and cement.

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

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

Alas, after the 60s, when there was a boom in panel construction, more than a hundred factories turned out to be useless. Production was curtailed, and good material was practically forgotten. It is urgent to correct this unfortunate misunderstanding!

What are the standard sizes?

To make wood concrete with your own hands, you need to have at least base view about the main standards used in its production. The requirements of GOST 19 22284 state that in order to obtain the maximum quality material only chips with dimensions of 40x10x5 mm should be used. Needles and leaves in the fill should be no more than 5%, and the volume of the bark - no more than 10%. As mentioned above, the most the best wood concrete obtained from clean and dry chips of deciduous trees.

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

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

We strongly recommend periodically carefully shoveling sawdust and shavings, otherwise air will not be able to access the deep layers of the tree. And further. Take care of the presence of a concrete mixer in advance, since by hand you simply cannot mix the finished composition with sufficient quality.

Chemistry

To make wood concrete with your own hands, you will need not only wood chips 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 harvested in an amount of 2-4% of the weight fraction of cement.

Getting Started

If the chips prepared by you do not quite correspond to the typical sizes that were given in our article, we recommend that you immediately pass it through the chipper.

Next, we carry out the primary sorting of the material, removing various impurities from the chips, large pieces of bark and needles. 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 Negative influence on the consistency of the cement mortar.

The best option is screening on a special screen, which gives the most clean and selected chips at the output. 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 materials.

After carefully shoveling the resulting mixture, soak the wood in water, where 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 there as well.

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 that, we load a portion of the composition into a concrete mixer, add water and cement, 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 in most farms this will never be obtained, the finished composition is simply raked out of the mixer and placed in molds. You can make them from fairly durable and quality wood. To ready blocks it was easier to get it, it is best to upholster them inner part film or linoleum.

Remember that the geometric proportions of the forms should be as correct as possible, otherwise the construction of houses from wood concrete will be very complicated. In order to properly compact the mixture (without the formation of air pockets), it is better to use electric rammers. If there is no opportunity to buy it, the manual version will do.

To make a normal arbolite monolithic, you can make such a fixture out of wood, simply upholstering it with sheet iron to ensure proper weight.

After it drains excess moisture and the block will acquire the desired shape, it is placed under the press, having previously wrapped plastic wrap. Exposure takes place within ten days, and the ambient temperature is considered to be optimal not higher than 15 degrees Celsius.

Today, the market for insulation materials is filled with large quantity a wide variety of materials, from mineral wool and ending with extruded polystyrene foam. However, even expensive materials do not guarantee complete heat preservation. Most of the experts in this field began to return to the long-known, but lost popularity, methods of thermal insulation of buildings. In this article we will talk about how insulation with sawdust is carried out.

sawdust types

Sawdust is small particles of recycled wood, which are obtained as a result of sawing. In appearance, they look like small dust.

Sawdust can be purchased in different fractions from 5 mm to 3 cm. The length depends on the technological process of the woodworking enterprise, namely on what type of tools is used in each case.

This material is environmentally friendly. In addition to low cost, sawdust has many other advantages, for example, excellent thermal insulation and sound-absorbing qualities, as well as a small specific gravity of the material. Mostly, sawdust is created from hardwoods such as spruce, pine or ash.

Ceiling insulation with sawdust

It is necessary to insulate the ceiling in a private house from any material, both from brick and from foam blocks. Because it is through the ceiling that significant heat loss occurs. Average heat loss through the ceiling is 20%. From an economic point of view, the most profitable is the insulation of the ceiling with sawdust.

Note that the laying of wood processing products is a laborious task. Before you start installation, you need to do a lot preparatory work. First of all, such work is aimed at protecting against fire, because wood in any form is extremely flammable. It is highly flammable and has a long burning time.

What materials and tools may be needed:

• sawdust of fine and coarse fraction
• sand, clay or slag
• lime and copper sulfate (you can take boric acid)
• substrate. For this purpose, you can use corrugated cardboard or any other breathable materials that have good vapor permeability.
• sealant and mounting foam
• flame retardant and wood preservative. These compounds are necessary if the ceiling boards are not covered with a protective material against mold and fungus, fire
• construction stapler and staples to it.

Work must begin with the protection of ceiling beams and boards from possible adverse factors. Most often, high-quality buildings are already built from processed timber. However, if this procedure was missed for some reason, then it is necessary to carry it out now.

Wooden elements must be protected comprehensively, and the following sequence must be observed:

• an antiseptic is applied first, which prevents rot and protects against insects
• next come fire and bioprotective agents that increase resistance to fire and high temperatures
• the third uses water repellents that prevent moisture from entering the wood structure. In addition, such products protect the wood from washing out previously applied solutions.

To achieve higher efficiency, it is worth purchasing all drugs from the same manufacturer.

After the protective work all seams and joints must be sealed with foam and sealant. In addition to gaps in ceiling you need to close up any other holes that may be present in the roof structure. This is necessary so that the insulation material does not come into contact with precipitation or strong wind, which can lift the thermal insulation layer. Don't forget to cut the protruding parts of the foam flush with ceiling beams, otherwise there will be voids in these places through which heat will escape.

Next, you can lay the substrate, which is needed to prevent the shedding of fine dust from sawdust from the ceiling. This dust can become a source of additional dust in the house. The substrate must have vapor-permeable qualities. If there are no such properties, then warm air and steam, rising up, will remain between the boards and materials, and cause additional condensate. As a result, mold may form due to excessive moisture. As a substrate, you can use any cardboard, for example, from old boxes, packaging. Most importantly, it must be completely dry.

Clean the ceiling boards from dirt and dust and lay cardboard sheets on them in several layers. Lay the underlay with an overlap of 15-30 cm so that sawdust does not get into the seams. Now you need a stapler, with which you need to fasten all the joints of the material.

Sawdust should be bought dry, without foreign odors. In advance, they should be treated with compositions of fire retardants and antiseptics. After the mass has dried, you can add 10% lime (fluff) and a small amount of blue vitriol(or borax). All this must be mixed well.

There are several basic methods for installing sawdust insulation. They can be covered dry or mixed with cement and diluted with water. Sawdust can be poured both in a clean dry form, and mixed with cement and diluted with water.

With the dry method, sawdust is poured in two layers:

• coarse fraction or shavings. This layer should be 10-15 cm thick. It must be well compacted
• smallest fraction. The second layer should be the same thickness as the first. And it also needs to be well tamped.

In addition, slag, sand or clay can be laid on top of the sawdust. These materials will save your sawdust from the appearance of rodents and the development of mold.

In order to insulate the ceiling with a wet method, you need to buy sawdust, which were made at least a year ago. Such sawdust will be slightly wet. However, make sure they are free of mold.

The ratio of chips, water and cement: 20:3:2. The mixture must be done in small volumes, because it dries quickly. The resulting solution must be poured between the floor beams onto a substrate or a layer of sand and compacted. The layer thickness should be 5-10 cm. The solution completely hardens and can be walked on.

Sawdust, as a heater, is great for floor insulation. As in the case of the ceiling, sawdust for floor insulation must be pre-treated from rodents, insects and microorganisms. To do this, it is better to use special ready-made solutions.

The difference between floor insulation and ceiling insulation is that it is very difficult to add an insulator that shrinks in the floor structure. Therefore, it is necessary to choose in advance a method in which the mass will not dry out over time. In practice, this means that when dealing with thermal insulation of the floor, it is worth using not dry sawdust, but mixed with different components and subsequently solidified.

To prepare this mixture, you need to add gypsum or cement to the sawdust. Observe the following proportions: 85% sawdust, 5% gypsum and 10% fluffy lime or lime paste, which must be taken twice as much as dry lime. Do not forget that gypsum hardens very quickly, faster than cement.

It makes no sense to dry the sawdust before kneading. On the contrary, if the sawdust is dry, it is worth adding a little water. The degree of readiness of the mixture is checked in the hands - if the lump does not crumble and does not spread, then the composition is ready.

If the insulation is carried out in a building that has already been in operation, then the existing flooring you will have to dismantle, re-treat the floors with an antiseptic from moisture-resistant mastic, and then mount the substrate from vapor barrier material or films.

The created mixture of sawdust is placed on the substrate and compacted well. The thickness of the layer should be approximately 10 cm. After tamping, the mass must be left to solidify, in about 2-3 weeks.

When using dry sawdust, you need to create a raised floor. All wooden parts must be covered with protective agents. Next, a rough floor is mounted on the base from boards, on which waterproofing is laid. Sawdust is poured on top of the hydraulic barrier. The layer should be 10 cm or more. Note that insulation with sawdust is not suitable if you are going to make a screed. Sawdust is characterized by low strength and serious shrinkage. Before installation finish coat, you need to leave the floor for 2-4 days. Over these few days, the sawdust will shrink by 2-3 cm and you will need to add an additional amount.

Be sure to keep in mind that if the sawdust is not provided with good waterproofing and ventilation (the gap between the finished floor and the layer of insulating material), then they may lose their heat-shielding qualities.

by the most tricky business can be called wall insulation, because for this you need to create a frame. The frame must be filled with sawdust and compacted by hand. For installation in frame wall coarse sawdust is suitable. With a dry version of the bookmark, it is worth taking care of thoroughly drying the sawdust so that there is no moisture left in them.

With the wet method, the mixture is prepared from wood chips, lime, gypsum or cement, with the obligatory addition of antiseptics. The thoroughly mixed mass is moistened, poured into the prepared frame and compacted tightly so that the material does not sag. Gypsum, like cement, after a while draws out all the available moisture, and makes the mass monolithic.

between the wall and insulation material it is imperative to lay a waterproofing material that has vapor-permeable qualities. It is from the quality of the tamping and the density of the bookmark that the effectiveness of the insulation and the level of shrinkage depend. If the ramming is not tight, voids will appear and heat loss will begin.

The mixture is laid in layers 20-30 cm high and rammed. After that, a second similar layer is poured. And so they repeat the actions at all heights. The thickness of the insulation depends on climatic conditions. For example, in the house seasonal residence a thickness of 15 cm is enough, but in a capital structure, a thickness of 25-30 cm is needed. The frame is created from wooden planks section 100x50 mm.

The mass hardens in about 1-2 weeks, and finally sets in about a month. All this time it is worth monitoring that the air humidity does not exceed 60-70%, and the temperature does not rise above 20-25 degrees. In addition, you need to regularly ventilate the room. After that, you can start finishing work.

Houses insulated with sawdust are great option. They combine high performance heat preservation with low labor costs.

sawdust house

In addition to insulation, sawdust is used for the full-fledged construction of buildings. However, buildings made of sawdust concrete are rare today. Nevertheless, experts assure that sawdust concrete is a very promising material that allows you to build economical housing with decent performance.

The manufacturing technology of such material involves the addition of binding components, for example, clay, lime, liquid glass. These additives reduce shrinkage phenomena and reduce the cost of modules. By adjusting the proportions of individual components, in relation to the total weight, it is possible to change the density, porosity and strength of the final product.

Practice shows that optimal protection is achieved after cladding, however, for example, a sawdust bath can also be used without cladding.

The advantages of sawdust concrete include:

• thermal conductivity 0.20-0.30 W/m°C. Wall, 40.00 cm thick, similar in warmth to a 90 cm brick wall
• strength 20.0-50.0 kg/cm². Such material perfectly resists deformations and shock loads, so it can be used for construction in areas with probable seismic activity.
• easy processing. Modules can be milled, nailed, drilled, processed with a hacksaw and saw. Consequently, material consumption is reduced, almost no waste
• shrinkage 0.50 - 1.00 %mm/m
• frost resistance - 25 cycles
• density 300-1200 kg/m³.

Of the shortcomings, we note:

• moisture absorption. This disadvantage can be combated by processing blocks with special compounds.
• the impossibility of building multi-storey buildings
• not very attractive appearance without finishing.

Material calculation

Consider an example to find out the average number of blocks needed to construct a building. For example, you need to build a house with dimensions of 15x10 m, with a wall height of 3.00 m. The perimeter of the building will be the sum of the lengths of all sides = 15 + 15 + 10 + 10 = 50 m. The area of ​​\u200b\u200bthe building is the perimeter times the height = 50 * 3 = 150 m². It is worth considering the thickness of the masonry, and the number of blocks in 1 m2.

Unfortunately, energy prices do not show a downward trend, therefore, in the construction of housing, the issues of truly effective thermal insulation of houses always come to the fore. There is a lot various technologies insulation of buildings using facade or placed inside materials, using special hinged construction etc . However, many issues are resolved already at the construction stage, if walls are used to build Construction Materials, with their own high thermal insulation qualities. One of these materials is wood concrete, or, as it is more commonly called, wood concrete.

Once widely used in construction, it was undeservedly forgotten over time, and many potential developers sometimes do not even know anything about it. However, wood concrete began to restore its position in demand, began to appear on sale. But if there is no opportunity to acquire it, you should not despair - there is always the opportunity to make wood concrete blocks with your own hands.

What is wood concrete, and what are its main advantages

The material, which is commonly called wood concrete, consists of two main ingredients. Its main mass is a filler made of wood chips and sawdust, which are interconnected by the second fraction - Portland cement. The total mass may include special chemical additives that improve the quality of wood or increase the plasticity of the resulting mixture, but their specific amount is very low.

It is not necessary to assume that such wood concrete is some kind of novelty in the family of building materials. On the contrary, the use of plant components with mineral binders has a long history - how can one not recall here the ancient technology of adobe construction, where the main ingredients are straw and clay. With the development of silicate production, when the production of cement began on a mass scale, the first experiments with wood concrete began to be carried out.

In the 50s - 60s of the twentieth century, wood concrete began to be produced in industrial scale. The material has passed comprehensive tests, received the appropriate GOST, was constantly modified - several research teams worked on this issue. A striking proof of the quality of the produced building materials is the fact that several buildings at the Antarctic stations, including the canteen and kitchen building, were built from wood concrete. The calculation justified itself - it was not very difficult to deliver such a light material over a huge distance, and the walls only 30 cm thick were supported in these extreme conditions comfort mode.

Unfortunately, in the future, the main emphasis on industrial production building materials were made on reinforced concrete, the problems of energy saving and ecology were then few who worried, and the wood concrete was undeservedly simply forgotten. A fairly wide network of enterprises for its production ceased to exist, no developments were carried out in this direction.

Nowadays, there is a "reanimation" of this direction in the production of wall materials. Arbolit began to be used again in construction, the demand for it increased. Many private entrepreneurs are engaged in the production of wood concrete - machine-building enterprises have even launched the production of special mini-lines. Adhering to certain technologies, it is quite possible to make arbolite blocks with your own hands and at home.

What wonderful qualities this material has, and what benefits it gives from its use:

• The first thing that attention is always drawn to is excellent thermal insulation characteristics. The wood is “warm” in itself, plus the “airiness” of the wood concrete plays a big role. Let's compare - only 300 - 400 mm of wood-concrete masonry resist the cold as effectively as Brick wall about 2 meters thick!

• Arbolite is an excellent sound insulator. Street noises will not penetrate into the house built from it.

• The material is light - its density is from 400 to 850 kg / m³. And this is the reduction in the cost of transportation, construction (no special lifting equipment is needed), the reduction of loads on the base of the building, and it is possible to use a simpler and more inexpensive foundation.
• The lightness of wood concrete does not at all mean its fragility. On the contrary, it has an enviable plasticity and cushioning qualities (compression - up to 10% of the volume) with good bending strength. Under loads, it will not crack or crumble, and after removing the effort, it tries to restore its previous shape - the reinforcing effect of wood chips affects. Strong accented impacts that destroy other wall materials are limited to only a dented surface, but without violating the overall structure of the block.

This is especially important when building buildings on problematic soils or in regions with increased seismic activity - the walls of the house will not crack.

• Wood concrete is environmentally friendly pure material. With proper pre-treatment of raw materials, it will not become nutrient medium for microorganisms, mold, insects or rodents. It does not undergo processes of debate and decay of the material with the release of substances harmful to human health. At the same time, it has excellent vapor permeability, the walls get the opportunity to "breathe", condensate does not accumulate in them.
• The material is practically non-combustible, despite the high component content of wood. When critical high temperatures retains a given shape much longer than other polymer-based insulation blocks.
• Arbolite walls are easily amenable to any kind exterior finish, showing excellent adhesion to most mortars and mixtures used, even without the use of additional reinforcing meshes.
• The plasticity of the starting material allows molding building blocks almost any, even the most bizarre configuration, which opens up a wide scope for architectural design.

• One of the important advantages is the ease of processing wood concrete blocks. They are easy to cut even with a conventional saw, they can be precisely adjusted to the required size during construction. In addition, it is easy to drill a hole of any diameter in the walls of this material, self-tapping screws are perfectly screwed into them and hammered nails are held.

Video: the positive qualities of wood concrete

"Elements" of technology for the production of wood concrete

First of all, it is necessary to make a reservation that all of the above and what will be discussed in the future refer specifically to wood concrete, that is, wood concrete. The fact is that sawdust concrete is often presented under the general term (it is made from sawdust of a fine fraction with the addition of sand), but there are more differences between these materials rather than similarities.

• For the production of wood concrete, wood chips are used, obtained by crushing wood. At the exit from the crushing machine, fragments are obtained with a length of 15 ÷ 20 mm, a width of about 10 and a thickness of 2 ÷ 3 mm. In an industrial environment, this is done special installations, quickly processing non-marketable wood - branches, slabs, tops of sawn trees, waste from woodworking enterprises.

By the way, not all types of wood are suitable for the production of wood concrete. Basically, these are, of course, conifers - pine, fir, spruce, but larch is not used for these purposes. Good material it is also obtained from individual hardwoods - poplar, aspen, birch. Beech waste for wood concrete cannot be used.

• The resulting wood pulp without fail undergoes a special chemical treatment. The structure of wood contains a lot of water-soluble substances of the sugar group, which not only reduce the performance of the material itself and significantly lengthen the time for the complete setting of cement, but can also cause fermentation processes in the thickness of already finished blocks. This can result in the formation of voids, swelling of the surface and other negative consequences.

Neutralization of these substances is carried out with solutions of calcium chloride, aluminum sulfate or "liquid glass" in a certain proportion. In addition, in order to prevent the development various forms biological life in the thickness of the material, wood chips are processed.

• The next stage of production is mixing the chip mass with a binder component - Portland cement. Its specific gravity is approximately 10 to 15%. Plasticizers can be added, but not more than 1% by weight.
• The resulting plastic mass enters the molding section. The technology can be different - pressing or compaction on a vibrating stand, depending on the intended purpose of the products obtained.

• After full filling forms, they are transferred to the drying area, where a certain temperature and humidity regime is maintained. Then comes the removal of molds (formwork), and the resulting blocks are dried in flowingie 2 days at a temperature of about 60 ºС.
• If necessary, finished products undergo mechanical refinement and then arrive at the warehouse for packaging and shipment to consumers.

The percentage composition of the components is not a clearly defined value - it can vary depending on certain limits depending on specific products and their intended purpose.

In the production of large-sized parts, their additional reinforcement can be used, including the installation of embedded technological plates and rigging loops.

Industrially produced wood concrete (you can find the names " Urmalit", " Timfort", " Woodstone", " Dyurizol" - they differ somewhat among themselves in the percentage of additional polymer components) is divided into structural and thermal insulation:

• The density of structural wood concrete reaches 850 kg / m³, surface strength is about M-50, thermal insulation properties are not too high - thermal conductivity is 0.14 - 0.17 W / (m × ° With).
• Thermal insulation wood concrete has a different picture - density up to 500 kg / m³, strength index within M-5 ÷ M-15, but the thermal conductivity is very low - 0.08 ÷ 0.1 W / (m × ° With).

How to make wood concrete blocks yourself

The number of mini-enterprises for the production of wood concrete blocks is growing (for some master entrepreneurs, this becomes very profitable business), and the material is increasingly found in free sale. But home craftsmen who always try to do everything on their own will never be translated.

What is needed for the manufacture of arbolite building parts:

• First of all, the most important material is needed - wood chips. It is clear that a lot of it is needed - it simply does not make sense to start a process because of several blocks. It is good if there are woodworking workshops nearby, where you can agree on an inexpensive purchase of such waste. Self-cooking chipping on a large scale is a very difficult task, unless, of course, a special chipper is available on the farm. craftsmen find original solutions by designing such installations on their own.

Video: homemade wood chipper

• It will definitely be required - manually preparing a significant amount of high-quality wood-cement mixture will not work.
• The required number of forms is prepared in advance. They can be made of wood (boards, thick plywood or OSB), and it is better if they are collapsible - the stripping process will be much simpler. Usually they make a long form with jumpers in order to make several blocks at once in it. To prevent the solution from sticking to wooden surface, the inner walls can be sheathed with old linoleum.

Another approach is a welded or also collapsible structure made of sheet metal with cells fucking blocks of a certain configuration and size. If desired, you can purchase or order factory molds, often even with tools for molding and pressing - they will allow you to make blocks complex configuration, including hollow ones.

• To compact the wet mass in the molds, it is necessary to prepare a rammer. You can also apply the vibrocompression technique. The easiest way is to use a perforator for this purpose with the transfer of its vibration to a stand with a spring-loaded surface. Another method is the manufacture of a stand with an electric motor installed on it, on the rotor of which an eccentric flywheel is installed.

• Certain chemicals may be needed to process wood - we will talk about them a little later.
• It is required to prepare a platform under a canopy to accommodate the filled forms and manufactured blocks for the drying cycle.

In what sequence is the work on the manufacture of arbolite blocks carried out:

1. Wood pulp is prepared. It must be cleaned of dirt, earth, dust. The total volume content of side components (bark, needles or leaves) should not exceed 5%.

Wood chips must be freed from dissolved sugars. The easiest way is to endure her outdoors, stirring occasionally. However, this will take a lot of time - about 3 months. To speed up the process, it is better to treat it with a 1.5% solution of technical calcium chloride at the rate of 200 liters of solution per 1 m³ of wood. The mass is kept in this state for up to 3 days with regular daily stirring. However, it should be remembered that this method is only suitable for conifers.

Another way is the treatment with "liquid glass", but it should be carried out already when the solution is mixed, since the silicate components can lead to sintering of the chip mass. And here there is a nuance - "liquid glass" can be used with any type of wood, but it will significantly reduce the plasticity of the resulting blocks, increase their fragility.

2. Before starting further work, the wood chips should be treated with lime mortar. It must completely neutralize all the chemical components of the tree, plus to this - give it antiseptic properties.

The chips are soaked in a solution of slaked lime (5÷10%) for 3 hours. Then it is laid out on a grid to let the water drain. Raw wood is no longer dried, but is immediately used for further preparation of the working molding mass.

3. The mixture for molding is being prepared. To do this, chips are first mixed in a concrete mixer. with water, with addition"liquid glass" (no more than 1% of total mass planned amount of solution). Upon receipt of a semi-liquid slurry, they begin to add cement (not lower than M-400) and gradually increase the amount of water. The general proportion should be maintained within the following limits: 4 parts of water to 3 parts of wood and 3 parts of cement.

Here, one must be careful not to widespread mistakes of novice masters who begin to measure the components in a volume ratio. The given proportions relate exclusively to the mass of materials introduced into the mixture.

The solution is mixed until completely homogeneous and breaking all possible lumps. As a result, the resulting mass should be plastic, but crumbly enough. When squeezing a lump in the palm of your hand, it should retain its shape without crumbling after the effort is removed.

4. The next step is molding. When the mixture is completely ready, the molds must be lightly smeared with liquid cement milk or oil mining. Wood-cement mass is laid out in them in stages, in 3-4 passes, with careful tamping of each layer. If there is a vibration stand, then this will greatly simplify the task. It makes sense to pierce the mixture several times with sharpened reinforcement in order to facilitate the release of air bubbles.

You can leave a free space on top, approximately 20 mm, and fill it plaster mortar smoothing the surface with a spatula. This will allow you to get blocks with a flat side already plastered.

There is another way to decorate blocks. Pebbles are placed at the bottom of the molds, tiles - whole or in fragments, then poured with ordinary dense concrete mortar to a thickness of about 20 mm, and only then the final molding of the block is carried out.

If reinforcement of the block is required, then first a layer of wood concrete is laid, then it is installed reinforcing mesh and a layer of concrete is poured, completely covering it, and a layer of wood concrete again goes on top.

Forms filled with mass are sent to the pre-drying place.

5. After a day, you can remove the formwork or remove the seized blocks from the molds. They are laid under a canopy for further drying and hardening. It usually takes two to three weeks, depending on air temperature and humidity.

Video - An example of the production of wood concrete at home

A well-organized process, in the presence of a sufficient number of molds and means of "small-scale mechanization", will make it possible to produce up to 80-100 blocks per day with such manual molding. This should fully ensure the uninterrupted construction of a house built from wood concrete.

Sawdust and cement blocks

Now you won’t surprise anyone in construction composite materials. What only yesterday coexisted peacefully, today, using new technologies, complements each other, mixes up. As a result, materials are obtained that have acquired the best quality characteristics from the mixed components, or even new properties in general. These materials 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 twofold: and the waste will go into action, solving the problem of their disposal, and the concrete will become much lighter.

Types of wood-cement materials

Since wood materials of different sizes and structure can be added as a 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;
• - fibrolite;
• - sawdust concrete;
• - CSP (cement particle boards);
• - xylolite.

And since the difference in composition leads to a difference in properties, materials with different performance characteristics are obtained. This allows the use of wood-cement materials in construction quite widely.

Arbolit

This is a lightweight concrete made from wood chips, water, chemical additives and a mineral binder, most often Portland cement. Crusher is obtained from both deciduous and coniferous species, it is even possible to fill concrete with flax or hemp bonfire, chopped straw, chopped cotton stalks.

The technology for the production of wood concrete is as follows:

1. 1. wood waste conveyors are fed into the chipper.
2. 2. The resulting wood chips are sent to the hammer mill.
3. 3. The pneumatic conveyor feeds the resulting product to a vibrating screen, from where dust and fine crushed material go to the waste bin, large crushed material is sent for re-crushing.
4. 4. The desired crushed fraction enters the soaking bath, from there through the dispenser into the mixer.
5. 5. Cement, water and chemical additives are supplied to the mixer through other different dispensers.
6. 6. The resulting mixture in the molds is compacted by presses or vibrocompression units.
7. 7. Molds with arbolite are subjected to heat treatment and drying.

The use of wood concrete: partitions, slabs for floors, ceilings and coatings, large-format wall panels, wall blocks, etc.

Fiberboard

It is a slab made of wood chips and a mineral binder. Chip length over 35 cm and 5-10 mm wide grinds down to wool. Further, the technological process looks like this: the chips are mineralized with potassium chloride, moistened and mixed with cement paste, plates 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 fibrolite as wall material, it should be plastered, and where the humidity is high, it cannot be used at all.

sawdust concrete

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

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

Cement particle boards

Of the wood-cement materials, they are used most often. For their manufacturewood shavings come, 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. However, they can also be used for facade works and for interior decoration. They are not afraid of high humidity, they have proven themselves in restoration work.

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

Xylolite

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

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

Further, the plates are molded under significant pressure (up to 10 MPa), at high temperature (up to 95 ° C) they harden in the curing chambers. Then, for full condition, the plates dry in warehouses for two weeks. In order to increase water resistance, the plates are impregnated with hydrophobic compounds. Most often, these boards are used for the production of floors.

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Arbolite blocks, otherwise wood concrete, is a building material patented in the first half of the last century and successfully used in modern construction low-rise buildings. The production is based on chips from deciduous or coniferous wood. The demand and competitiveness of wood concrete among other materials is due to its affordable cost, light weight, environmental friendliness and ease of use, optimal thermal insulation performance.

Wood chips for wood concrete is the basic component and takes from 75% to 90% of the total volume of the mixture. Depending on the quality of the main raw material, its shape and fraction are directly dependent performance characteristics finished material.

Chips for wood concrete according to GOST

The size of wood chips for wood concrete, the technology of creation, the percentage of initial components are regulated by the regulatory framework for the manufacture and use of wood concrete: GOST 19222-84 “Arbolite and products from it. General technical conditions".

Permissible chip sizes according to GOST:

• length - up to 40 mm;
• width - up to 10 mm;
• thickness - up to 5 mm.

Chips are obtained by grinding rejected wood: tops, knots, slabs. It is preferable to use coniferous wood. GOST allows the presence of crushed bark up to 10% and needles up to 5% of general composition masses.

The needle shape of wood chips will increase the strength of the finished material and create an additional reinforcing effect.

In some cases, manufacturers add cotton, flax, hemp, wood shavings or sawdust for wood concrete to the organic component. In this case, the finished material is less durable, but with improved thermal insulation qualities.

Before using the wood base for the production of wood concrete, it must be processed antiseptics to prevent the formation of fungal infections during the operation of the blocks.

Buy or make wood chips with your own hands

As soon as a private developer has decided to make arbolite blocks on his own, the question arises whether it is more profitable to buy or make wood chips for building blanks. If you plan to build a small country house, then the purchase of ready-made raw materials will reduce working time and financial costs.

Specialized equipment for the manufacture of wood chips is not cheap equipment. Processing with chemicals takes time.

If a decision is made to produce wood-concrete blocks in large quantities, or to engage in construction activities, then it is more profitable to produce wood chips on your own.

The process of making chips for wood concrete with your own hands consists in a sequence of actions:

• selection of suitable wood;
• obtaining chips using special equipment;
• processing chips with chemicals to remove sugars.

For independent production of chips, it is preferable to use pine that is not damaged by pests. Pine chips retain heat to a greater extent and are easier to process with chemicals.

Requirements for wood chips for wood concrete blocks:

1. Absence of foreign impurities: stones, ice, clay, sand.
2. Absence of rot, mold fungi, other damage.
3. The content of tree bark is within 10%, needles - 5% of the total mass.
4. Standard size 40105 mm.

In the manufacture of wood concrete with your own hands, the presence of sawdust up to 30% is allowed. In this case, the consumption of cement increases, and the strength of the finished material decreases. Arbolite blocks with an admixture of sawdust are distinguished by increased heat-saving properties. Used as an insulating building material.

What sawdust is needed for wood concrete? Sawdust of coniferous and hardwood is used, as in the preparation of wood chips. In order to purchase, it is possible to contact woodworking enterprises.

Technological equipment for the production of wood chips

The best option for obtaining chips with the correct needle shape and acceptable fraction size is a woodworking shredder. Its only drawback is its high cost.

Machines differ from each other according to the principle of operation. The choice of an acceptable option is determined by the volume of production, the properties of the feedstock, the possibility of placement on the construction site, and the technical features of processing.

Types of crushing equipment:

1. Chipping machines of disk type. Some of the models have adjustment of the location and inclination of the knives. This makes it possible to obtain chips different size. Able to process wooden blanks of any shape.
2. Drum-type shredders. Allows you to recycle both wooden beams and waste furniture production, logging farms. The machines are equipped with a large loading hopper into which the feedstock is fed. Then there is a drum mechanism with double-sided knives.
3. Hammer type crushers. Are issued with one working shaft, or with two shafts. They are a rotary device equipped with hammers and chippers. Once inside, wood for wood concrete moves between hammers and special dividing plates, wedged and crushed from impacts, after which it is sieved through a sieve into the outlet compartment. The final size of the chips depends on the dimensions of the sieve cell.

All three types of machines have manual loading of raw materials. To ensure labor safety, it is preferable to use long pieces of wood. To load smaller material, you should use a shovel or other the right tool with a long handle.

Raw wood is used to make wood chips. Only in this case, the shape and size of the fraction of the obtained product corresponds to regulatory requirements. The use of dry wood is fraught with the formation of small chips, which will require an increased consumption of the cement mixture.

Preparation of chips for the manufacture of wood concrete blocks

Wood raw materials contain harmful substances - sugars that can increase the setting time of the cement mixture, reduce the strength of finished wood concrete blocks. The primary task of preparing an arbolite mixture is the processing and preparation of wood chips.

The main methods of processing organic filler:

Having studied the theory of how to make wood chips for wood concrete and having mastered practical skills, it is enough just to establish independent production chips for wood concrete. It is preferable to purchase initial organic raw materials from logging and woodworking enterprises. If the wood component is required to build one house, it would be wiser to purchase wood chips or ready-made wood concrete blocks from manufacturers. To obtain a quality guarantee for the purchased materials, you should contact licensed manufacturers who are ready to provide the necessary certificates and documents.