The search for a universal building material, optimal in its thermal, strength and environmental characteristics, culminated in the invention of wood concrete. This happened in the 50s of the last century in the former USSR.
Having comprehensively studied the unique properties of wood concrete (the second name for wood concrete), Soviet scientists gave it the green light. The main customer of the new structural and thermal insulation material was the northern regions Soviet Union, where the construction of wood concrete houses progressed at an accelerated pace.
Unfortunately, in the late 90s of the 20th century, the use of this unique material began to decline, as it became more profitable to build residential buildings from large-sized expanded clay concrete panels.
Today, wood concrete is experiencing a rebirth and every year it is increasingly used in individual construction. Therefore we have no right to ignore this interesting material and not consider in detail all its pros and cons.
It should be noted that in the last century, wood concrete was used not only for the manufacture of wall blocks, but was also produced in the form of sheets, which were used for insulation and soundproofing of floors.
Today, wood concrete is practically not used in this capacity, because its main advantages are revealed during the construction of low-rise buildings. Let us list them in more detail.
— Low thermal conductivity
Wood concrete wall blocks belong to the category of effective heat-insulating materials. This is evidenced by the following fact: a wall made of wood concrete with a thickness of only 30 cm retains heat just as well as brickwork a meter thick.
Therefore, reviews from owners of houses made of wood concrete blocks primarily note significant fuel savings even in the coldest winters.
— Durability
The strength of wood concrete blocks directly depends on their density. For structural and thermal insulating wood concrete with a density of 600-650 kg/m3, it ranges from 20 to 35 kg/cm2. According to this indicator, wood concrete is practically no different from its main competitors - foam and aerated concrete.
An important advantage is the plasticity of this material. This fact is explained by the fact that the composition of arbolite blocks includes wood chips that reinforce this material. Therefore, under load, wood concrete does not crack, but only slightly deforms without loss of integrity.
By building a house from wood concrete, you will not have to spend extra money and time on pouring concrete reinforced belt, which is necessary for fragile walls made of gas and foam concrete blocks.
— Frost resistance
Wood concrete's frost resistance (the number of freezing-thawing cycles in a water-saturated state) ranges from 25 to 50. In practice, this means that a house made of this material will last at least 50 years (confirmed by studies of existing buildings). Foam blocks have resistance to freezing and thawing that does not exceed 35 cycles.
Speaking about the advantages of wood concrete, we should also talk about its low carbonization shrinkage. This term refers to the process of loss of strength of cement stone due to reaction with atmospheric carbon dioxide, which results in soft chalk.
— Good sound insulation
For arbolite blocks in the acoustic range from 125 to 2000 Hz, the sound absorption coefficient ranges from 0.17 to 0.6. For brick, this indicator is almost four times worse. For wood it ranges from 0.06 to 0.1, which is also significantly less than for wood concrete.
- A light weight
1 m3 of blocks made of structural and thermal insulating wood concrete weighs almost 3 times less than brick and almost 1.5 times less than expanded clay concrete. This allows you to significantly reduce the cost of constructing foundations for arbolite walls.
— Environmental friendliness and durability
Wood concrete is one of the most environmentally friendly building materials, since it contains only natural ingredients - cement stone, wood chips, water, calcium chloride (used in Food Industry) or ordinary lime milk.
This material behaves excellently in walls because it does not rot and is not afraid of mold fungi and doesn't burn. In addition, wood concrete breathes well and regulates air humidity in the room, absorbing excess moisture and releasing it when there is a lack.
— Non-flammability
Arbolit belongs to the group flame retardant materials(flammability group G1). In addition, wood concrete is a low-flammable material (flammability group B1) and a low-smoke material (D1).
— Ease of processing
Wood concrete is easily processed with any mechanical tool. It can be sawed and drilled and holds nails and screws well. The rough surface of the blocks is an ideal basis for applying plaster solutions without the use of reinforcing mesh.
The disadvantages of arbolite blocks include low accuracy geometric dimensions. Therefore, walls made of this material require leveling with plaster solutions or sheets. finishing materials(plasterboard, magnesite, lining, siding).
Since the wood concrete manufacturing technology is based on the use of wood chips, a fairly expensive material, the cost of wood concrete blocks exceeds the price of aerated concrete by an average of 15-20%.
1m3 of wood concrete blocks (500x250x400 mm) costs from 4000 to 5200 rubles, while aerated concrete blocks Manufacturers offer prices ranging from 3,400 to 3,800 rubles.
The wood concrete production business is one of the most interesting at the current time. This is due to the high (and growing) popularity of the material among end customers, the ease of manufacturing arbolite blocks, and finally, the lack of time-tested manufacturers plays a significant role.
Federal retail "" invites you to consider purchasing. At the same time, we will not only supply you with the best equipment currently on the market (we have been producing it for 10 years; the former name of the Russian Arbolit company is the Sphere Experimental Design Bureau), but we will also ensure that your capacities are fully loaded with our orders.
Considering the fairly high price of high-quality wood concrete, many developers have a natural question about the possibility of its self-made. At first glance, it seems that there is nothing complicated in this process: mix cement with wood chips, add water and form your own blocks.
However, making wood concrete with your own hands on your own site will be much more difficult than in theoretical discussions.
Firstly, almost all home craftsmen presenting their own technologies making blocks with the addition of crushed wood, in fact, they are not talking about wood concrete, but about sawdust concrete. This is a fundamental difference. Sawdust concrete not only differs significantly in composition from wood concrete, but is also worse in its strength and thermal characteristics.
Secondly, wood chips must meet fairly stringent requirements. Its thickness should not exceed 5 mm, and its length should not exceed 25 mm.
Therefore, in production, all wood is first passed through a crushing machine and only then mixed with cement.
Thirdly, sucrose is a serious enemy of the strength of wood concrete blocks. It is contained in wood and must be neutralized. For this purpose, enterprises use safe calcium chloride or aluminum sulfate. You may not have these substances at home.
If you nevertheless find wood chips suitable for the fraction, then the sucrose neutralizer can be replaced with a solution of slaked lime. The wood chips must be kept in it for at least 3 hours. Another option for replacing sucrose neutralizers is to keep the crushed wood pulp under open air within 3 months.
The simplest equipment for the production of wood concrete blocks includes a mortar mixer and a vibrating molding machine. The cost of such a kit is about 58,000 rubles, so it will only pay off if there are large volumes of production (building a house or private business).
The initial mixture for the production of wood concrete blocks is prepared in a ratio of 4:3:3 (water, wood chips, cement). Sawdust and shavings can be added to wood concrete, but their amount should not exceed 5-10% of the total volume of wood raw materials.
Wood- cement mortar mix in a concrete mixer until a homogeneous mass is formed. It should not be watery, but crumbly. When you squeeze it in your fist, the resulting lump should hold its shape well and not fall apart.
After placing the mixture in a metal mold, it is vibrated on a machine, after which the finished block is placed under a canopy for 3 weeks to gain brand strength.
Useful video
Concrete when using sawdust as a filler on line of concretes closer to the classics than wood concrete.
It's all about the presence of sand in the composition of sawdust concrete.
No matter how similar in composition wood concrete and sawdust concrete are to each other - there is a difference, and sometimes it is significant.
We will not analyze the differences; we will consider in detail only the sawdust concrete itself.
There are types of sawdust concrete:
Like any other concrete, sawdust concrete gains strength best in heat and humidity, since moisture does not evaporate quickly and goes into the formation of cement stone.
The main advantages of sawdust concrete are:
There is only one main drawback: not all sawdust will do for this material. If in the case of sugars from the chips were removed during storage, and according to the ratio of the volume of chips and the specific area of the chips, the decomposition of sugars did not greatly affect the cement, then in the case of sawdust concrete, the process of decomposition of sugars greatly affects the cement itself inside the block.
In the process of producing sawdust concrete, it is important to take only the most suitable sawdust from those wood species that have sugar content is minimal. Optimal candidates for a second life of waste in sawdust concrete:
Larch, despite its high density and strength characteristics is in the very last place, With the greatest content sugars
If spruce begins to gain strength two weeks after setting, then the end occurs somewhere on the fortieth day after production. But for larch this period is much longer: from thirty days at the beginning of strength gain to one hundred and forty at the end.
All works on monolithic sawdust concrete needs to be done in the spring so that everything will be finished by the fall. Due to the released sugars, it is better to bring sawdust to condition for fresh air, including watering the sawdust to wash away any remaining sugar decay.
A couple of washes with water will already provide the sawdust with an acceptable condition for use in the process of manufacturing sawdust concrete. Sawdust structure when stored in bulk, it will prevent the processes of rotting and burning from starting. Since they are not compressed, there is no need to be afraid of moisture.
Any brand of sawdust concrete contains:
Differences in proportions observed only in the ratio of mixture components.
Each brand of sawdust concrete has its own proportions.
We prepare sawdust concrete with our own hands. We display the proportions of components per 1m3 of the finished mixture in the form of a table:
As we see, with an increase in the amount of cement, the purpose of the blocks is more limited to the construction of non-residential buildings. This is explained by the change in the coefficient thermal conductivity of blocks, nullifying all efforts to heat the building. When using M10 brand blocks, the coefficient is 0.21, which is a very good indicator.
For grade M15, this coefficient is 0.24, which is caused only by a slight increase in strength requirements, respectively, and an increase in the amount of cement to obtain a strong block for construction two-story house. For the M25 block, the coefficient is already almost 0.39, which is two times higher than for the M10 block. This means that the M25 block is twice as cold, but from it you can build large rooms.
The golden mean for sawdust concrete is one-story buildings.
The proportions of sawdust concrete are shown in the table:
In volume units this means the following. When producing sawdust concrete:
It is important to follow exactly this recipe, because it was worked for decades, much earlier than wood concrete. The lack of progression in quantity and proportions should not be confusing. In each individual case, the components work differently.
Slaked lime as a component is used both as a means of desugaring sawdust, and bypassing this stage, by introducing the required amount of fluff into the mixture.
Surprisingly, the most easy way preparing the mixture is manual. When preparing sawdust concrete with your own hands, ordinary concrete mixers will not work. Due to the lightness of some components, they risk remaining on the walls of the concrete mixer, or simply floating on top of the water. Any loading order.
You can first:
Another variant:
No matter what other people say, it makes absolutely no difference which option you choose.
As a result of the work, a homogeneous mixture is formed, the structure of which contains sand and cement. It is these two components that form cement stone. The lime neutralizes the sugars as they are released from the sawdust, and the sawdust itself is a filler. Classic lightweight concrete.
Machine mixing of sawdust concrete functionally possible if a stirrer is available forced type, as in the production of polystyrene concrete. But even in that case, the order does not matter, since if the sawdust has already been treated with lime during preparation, then it is no longer afraid of water.
It is worth mentioning a little about a mixture where building gypsum is used instead of cement.
And let people not be afraid of the speed of setting of gypsum in combination with water, since these issues have already found a popular solution.
The problem is solved by adding ordinary detergent, and as is known, it releases water in doses to gypsum molecules that are in an unhydrated state.
Explanation: building gypsum in the form in which it is sold in stores has ability to connect with water, forming a formula already with it, and which is already a solid formation that is not particularly afraid of water.
There is still no end to the debate as to whether it is possible to build external walls from gypsum-based blocks.
According to some data, with proven technology (on hand) and when protecting the blocks from atmospheric influences, it is quite possible to use these blocks for building external walls. Internal ones can definitely be built.
The only question is the price for the binder, but in terms of the volume of sawdust and the setting force, we can say that the costs will be slightly higher, and the rate of strength gain will be four to five times higher.
The size of sawdust does not matter if there is enough binder.
As a rule, sawdust is taken from a sawmill, and the differences in sawdust from strip and disk sawmill so insignificant that they are not taken into account at all.
The chips from rounding and calibrating machines will no longer work.
A homogeneous mixture will not work if in one volume there are fractions that differ from each other in volume by several hundred times.
Among the features of the process - it's important to knead so that when you pick up a lump of mixture and squeeze it with your hands, water does not flow from it in a stream. Although everyone’s strength is different, and you need to approach this issue logically. And after the lump has formed - so that it does not crumble in your hands.
Also for these nuances, lime is present in the solution. She provides mutual adhesion both between sand and cement, and between them and sawdust.
Manual mixing of sawdust concrete using a shovel:
Truly a folk building material, as it is the most affordable of materials according to the complexity of production. Perhaps people notice a wave-like interest in such materials. If before there was sawdust concrete good option for the whole country, then with the wave of Western marketing, people, in pursuit of fashion, moved away from a reasonable framework of choice.
Only now many have begun to pay attention to environmental friendliness and practicality building materials, and not for something that was designed for completely different climatic conditions. The following are successfully built from sawdust concrete:
Like any moderately hygroscopic material, sawdust concrete needs exterior decoration, just like aerated concrete and foam concrete.
If we consider sawdust concrete in comparison with autoclaved aerated concrete, then the water absorption of the latter is generally 200% of the mass of the block. Therefore, there is no need to be embarrassed by the presence of sawdust in the blocks. A popular insulation material that was produced in Germany at the beginning of the last century - ecowool - is generally made from what is collected from landfills.
Therefore, it is still worth figuring out what is more environmentally friendly - sawdust concrete with natural ingredients , or ecowool with a hypercontent of bromine salts.
Construction wall blocks, made from cement and wood shavings, according to GOST 19222-84 are called “arbolite products” and, if necessary, can be made at home on their own.
The technology for making building blocks from wood concrete was developed in the USSR back in the 60s of the last century. A number of factories were built and launched. However, due to the “victory” of panel construction technology, wood concrete was forgotten and returned to it only recently. This is a unique building material that combines excellent thermal insulation properties, low cost and ease of manufacture.
Blocks from shavings and cement on your own - recommendations from specialists:
Before you start pouring internal surfaces The molds are lubricated with grease, machine oil or a special release solution. Next, a mixture of cement with sawdust and additives is loaded into the mold layer by layer. Each successive layer is compacted with a piece of timber covered with galvanized steel or a mechanical vibratory rammer.
The filled and compacted forms are left for a day, after which the blocks are carefully removed, placed in a cool place and covered with plastic wrap. On hot days, to avoid drying out, the blocks are sprayed with water. After 14-20 days (subject to temperature environment 20 or more degrees Celsius) the blocks are ready for use.
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, because this is the most economically profitable due to the low cost and availability of metalwork waste, the block itself can be produced with your own hands.
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 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 of the cement composition will be lower.
The exact proportions of the components of wood concrete depend on the chosen brand.
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 comply in geometry and dimensions with GOST.
Wood chips must be needle-shaped and fit into the following dimensions:
To prepare it yourself, you need to use special chipping machines, which a short time are capable of processing various tree knots and tops, waste from the wood processing industry and slabs into chips. Most often used for making wood chips coniferous trees
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.
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.
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.
disk.
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 point, 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.
Such crushers come in single-shaft and double-shaft types, for home production The first type of apparatus 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.
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. The maximum diameter of the log is 10 cm.
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:
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.
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.
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, they are most often used conifers trees, 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 passed, 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!
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 highest quality material, only chips with dimensions of 40x10x5 mm should be used. The amount of needles and leaves in the filling 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, you need to prepare required quantity 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.
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.
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, it will not be possible to obtain 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 have a negative impact 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.
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 make it easier to get ready-made blocks, it is best to cover their inside 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 from wood, simply covering it with sheet iron to ensure the 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.
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