Arbolite or cement chip blocks are a material for the construction of buildings: this is lightweight concrete, which includes mineral binders and aggregates (waste from sawmilling and woodworking, 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 decay, fire resistant and easy to use, suitable for individual housing construction up to 3 floors inclusive. Wood concrete blocks for 80-85% consist of wood filler (wood chips, crushed or shavings from 2 to 25 mm long, 5 mm thick) and high-quality cement, at least ПЦ500.
Production technology
Today, in the manufacture of (CSB, CSP) mainly pine chips are used, but according to GOST 19222-84, other wood processing wastes (from hardwood and coniferous species) are also allowed. Nevertheless, wood concrete of the best quality comes out of pine or spruce shavings, since these rocks have the least amount of organic component (sucrose) that needs to be neutralized.
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 wood damage by a fungus 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 is put on the conveyor in many cities of Russia, but you can make blocks with your own hands if you clearly follow the technological process and acquire a minimum set of tools:
- Special crusher.
- Concrete mixer.
- Forms for blocks.
- Vibropress or vibrating table.
- Drying chamber or space under a canopy.
Types and form of issue of CSB
By density, wood concrete blocks are of the following types:
1. heat-insulating 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 walls (600x300x120 mm).
Dimensions
Dimensions of blocks of cement and shavings for the construction of external walls - 300x200x500 mm (per 1 m3> - 33 pieces), and for internal partitions you can use 120x300x600 mm, 47 pieces per m3, respectively.
In terms of economic and operational characteristics, houses made of wood concrete are much better than structures made of other materials. So, a house made of TsSB or TsSP is dry and warm, its walls are light, fire-resistant, retain heat well in winter and cool in summer, are convenient for decoration, durable and cheap.
Each building material has its advantages and disadvantages, and wood concrete is no exception, consider the pros and cons of such blocks.
Advantages of wood concrete
1. 1 m2 of walls built from wood concrete is 3 times lighter than structures made of expanded clay concrete and 8 times lighter than brick structures. This makes it possible to unload the foundation.
2. The cost of building a residential building from CSB is 40% less than from other materials.
3. Products made of chips and cement stone have a porous structure, which ensures natural air circulation 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 perfectly sawn and cut (you can make the most accurate fit), drilled, chopped, hold screws and nails.
6. Exceeding the maximum permissible loads on wood concrete leads to its compression and subsequent restoration, and not cracking, which allows you to painlessly endure shrinkage at home.
7. The strength of cement-bonded materials (CSB and CSP) in tension and bending allows the use of all types of floors (wood, reinforced concrete).
Minuses
1. Limited number of storeys of the building.
2. The low prevalence of wood concrete and it is difficult to buy it in some parts of Russia.
3. Water permeability, but this drawback is eliminated by plastering the walls.
4. A large number of unscrupulous manufacturers producing blocks of poor quality and different in composition.
As you can see, the positive qualities of this material more than compensate for its insignificant disadvantages.
In terms of thermal conductivity and fire resistance, CSP and CSB are superior to all traditional building materials. The properties of wood concrete, including cement-bonded particle boards, made it possible to use them for the construction of buildings even in the conditions of Antarctica. There are many good reviews about it abroad, it is widely used there and is valued for its energy-saving, heat-storing and sound-proofing properties.
The given technical characteristics of the blocks clearly demonstrate the combination of material qualities that make it possible to build warm and environmentally friendly two-three-story buildings.
Reviews of home owners
“I decided to calculate the cost, and it turned out that for 1 m3 of wood concrete you need Portland cement for approximately 1,200 rubles (already at new prices). Add more work and other materials, additives, then the cost will reach up to 2,500 - 3,000. Considering that a cube of wood in the region of six thousand 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 CSB - construction is going much faster. There is only one thing, but in order to find a conscientious manufacturer of these same blocks and cement-bonded particle boards, I had to search half the Internet and go through a lot of reviews. We were very pleased with the house, it breathes in such a house, as in a wooden one!
Andrey, St. Petersburg.
“From personal experience I’ll say that next time I won’t get involved with wood concrete in any case, and I also don’t advise anyone. The material is undeniably solid, just perfect, but, unfortunately, as often happens, the production is absolutely disgusting.
Elina, Kazan.
“When I come to visit a friend, he has a house from the Central Security Council, it takes so envy that I don’t have this. Honestly, I don’t know the disadvantages of wood concrete, it’s good for everyone! ”
Mikhail Plotnikov, Yekaterinburg.
The cost of cement chip products
You can buy wood concrete from manufacturers or in building 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 format 400x200x200 mm will be 68 rubles, and the cost of 1 m3 will be 4,300 rubles, respectively, excluding transportation.
| Name | standard | structural | septal | hollow | |||
| Price, rub/m3 | 3700 | 3700 | 4300 | 4600 | 4500 | 5000 | 3200 |
| Number of blocks per m3/pc | 33 | 25 | 14 | 23 | 21 | 47 | 27 |
| Length | 500 | 500 | 600 | 500 | 600 | 600 | 500 |
| Width | 300 | 400 | 400 | 250 | 400 | 300 | 300 |
| Height | 200 | 200 | 300 | 350 | 200 | 120 | 250 |
The search for a universal building material, optimal in terms of its thermal, strength and environmental characteristics, was crowned with the invention of wood concrete. It happened in the 50s of the last century in the former USSR.
Having comprehensively studied the unique properties of wood concrete (the second name of wood concrete), Soviet scientists gave it a "green light". The main customer of the new structural and heat-insulating material was the northern regions of the Soviet Union, where the construction of houses from wood concrete advanced at an accelerated pace.
Unfortunately, in the late 90s of the 20th century, the use of this unique material began to decline, since 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 pass by this interesting material and not consider in detail all its pros and cons.
Advantages and disadvantages of wood concrete blocks
It should be noted that in the last century, wood concrete was used not only for the manufacture of wall blocks, but also produced in the form of sheets, which were used for insulation and soundproofing 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's 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 of arbolite with a thickness of only 30 cm retains heat just as well as a meter-thick brickwork.
Therefore, in the reviews of the owners of houses from wood concrete blocks, first of all, significant fuel savings are noted even in the coldest winters.
- Durability
The strength of wood concrete blocks directly depends on their density. For structural and heat-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 practically does not differ 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 wood chips, which reinforce this material, are part of the wood concrete blocks. Therefore, under load, wood concrete does not crack, but only slightly deforms without loss of integrity.
When building a house from wood concrete, you do not have to spend extra money and time on pouring a concrete reinforced belt, which is necessary for fragile walls made of gas and foam concrete blocks.
— Frost resistance
Wood concrete has frost resistance (the number of freeze-thaw 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). In foam blocks, the resistance to freezing and thawing does not exceed 35 cycles.
Speaking about the advantages of wood concrete, it should also be said about its low carbonization shrinkage. This term refers to the process of loss of strength of cement stone due to the reaction with atmospheric carbon dioxide, which results in soft chalk.
- Good soundproofing
For wood concrete blocks in the acoustic range from 125 to 2000 Hz, the sound absorption coefficient is from 0.17 - 0.6. For brick, this figure is almost four times worse. For wood, it is in the range 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 heat-insulating wood concrete weighs almost 3 times less than a brick and almost 1.5 times less than expanded clay concrete. This allows you to significantly reduce the cost of building foundations for wood concrete walls.
- Environmental friendliness and durability
Wood concrete is one of the most environmentally friendly building materials, since it contains only natural components - cement stone, wood chips, water, calcium chloride (used in the food industry) or ordinary milk of lime.
In the wall, this material behaves excellently, because it does not rot, is not afraid of mold fungi and does not burn. In addition, wood concrete breathes well and regulates the humidity in the room, absorbing excess moisture and releasing it when there is a shortage.
— Fire resistance
Arbolit belongs to the group of slow-burning materials (combustibility group G1). In addition, wood concrete is difficult to ignite (flammability group B1) and low-smoke-forming material (D1).
- Ease of processing
Wood concrete is easily processed with any mechanical tool. It can be sawn 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 meshes.
The disadvantages of arbolite blocks include low dimensional accuracy. Therefore, walls made of this material require leveling with plaster mortars or sheet finishing materials (drywall, magnesite, lining, siding).
Since the technology for the manufacture of wood concrete is based on the use of wood chips - a rather expensive material, the cost of wood concrete blocks exceeds the price of aerated concrete by an average of 15-20%.
1 m3 of wood concrete blocks (500x250x400 mm) costs from 4000 to 5200 rubles, while manufacturers offer aerated concrete blocks at a price of 3400 to 3800 rubles.
The wood concrete production business is one of the most interesting at the moment. This is due to the high (and growing) popularity of the material among end customers, the ease of manufacture of wood concrete blocks, and finally, the lack of time-tested manufacturers plays an important 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 already, the former name of the Russian Arbolit company is the Experimental Design Bureau Sfera), but we will also ensure that your capacities are fully loaded with our orders.
We make arbolite blocks ourselves
Considering the rather high price of high-quality wood concrete, many developers have a natural question about the possibility of its self-production. At first glance, it seems that there is nothing complicated in this process: I mixed cement with wood chips, added water and formed blocks for myself.
However, making wood concrete with your own hands on your site will be much more difficult than in theoretical reasoning.
Firstly, almost all home craftsmen presenting their own technologies the manufacture of blocks with the addition of chopped 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 terms of its strength and thermal characteristics.
Secondly, wood chips for wood concrete must meet fairly stringent requirements.. Its thickness should not exceed 5 mm, and its length - 25 mm.
Therefore, in production, all wood is first passed through a crusher 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. To do this, enterprises use safe calcium chloride or aluminum sulfate. At home, you may not have these substances.
If you nevertheless found wood chips suitable for wood concrete fraction, then the sucrose neutralizer can be replaced with a solution of slaked lime. In it, chips must be kept for at least 3 hours. Another option to replace sucrose neutralizers is to store the crushed wood pulp outdoors for 3 months.
The simplest equipment for the production of wood concrete blocks includes a mortar mixer and a forming vibrating machine. The cost of such a kit is about 58,000 rubles, so it will pay off only if there is a large volume of production (building a house or a private business).
The initial mixture for the manufacture 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.
The wood-cement mortar is mixed in a concrete mixer until a homogeneous mass is formed. It should not be watery, but crumbly. When squeezing it in a fist, the resulting lump should keep its shape well and not fall apart.
After laying the mixture in a metal mold, it is vibrated on the machine, after which the finished block is placed under a canopy for 3 weeks to gain brand strength.
Useful video
In accordance with the current legislation, in Russia, concrete with organic aggregates can be used in low-rise construction
Wood concrete material- lightweight concrete with organic aggregates (up to 80-90% of the volume). It was invented by the Dutch around the 30s of the last century. However, in fact, the idea of using organics as aggregate in concrete - sawdust, wood chips, straw, and so on - has a longer history.
In Central Asia, houses were traditionally built from adobe - a mixture of clay and chopped straw. By the way, adobe is still produced in private farmsteads. Bricks were made from a mixture of clay and straw, which were dried in the sun. Wall blocks similar in shape to a melon called "guval" were also popular. They were made from the same material. Such bricks and "blocks" did not have sufficient strength. But in the local climate with poor rainfall, they served for a long time and reliably.
In the USSR, wood concrete became popular in the 60s. GOST was developed, copied from the manufacturing technology of the Dutch material under the DURISOL trademark. By this time, wood concrete had already won a place in the markets of Europe and America due to its environmental friendliness, good heat and sound insulating properties and the low specific gravity of the finished wall structure. Abroad, this material is called differently: "Dyurisol" - in Holland and Sweden, "Woodstone" - in the USA and Canada, "Pilinobeton" - in the Czech Republic, "Centeriboad" - in Japan, "Duripanel" - in Germany, "Velox " - in Austria. It is used in the construction of not only private houses, but also high-rise industrial buildings.
Types of blocks from wood concrete
Composition and tenology of wood concrete very simple - cement, special wood chips, air-breathing additive. For industrial production, equipment is needed - a chip cutter, a concrete mixer, molds.
The Soviet analogue of "Dyurisol" passed all technical tests, was standardized and certified. More than a hundred arbolite plants worked in the USSR. By the way, the material was used for the construction of buildings even in Antarctica. At the Molodezhnaya station, three service buildings and a canteen were built from wood concrete panels. The thickness of the walls was only 30 cm. There are practically no minuses for such a material, but there are many pluses. Foundations for it are required the same as for aerated concrete.
Wood concrete houses quite warm and durable, because such building blocks are made in accordance with the technology. The price of such a house is comparable to the price of a house made of foam-gas-concrete. But at their core, these houses are more environmentally friendly.
However, in the Soviet Union, wood concrete did not become a material of mass use. A course was taken for the construction of large-scale concrete-block houses, for which wood concrete was not suitable due to its characteristics. In the 1990s, the wood concrete industry in Russia fell into decline. But the state of buildings built from wood concrete 60 years ago shows that the material is quite suitable for use in construction. Moreover, technology does not stand still.
Chip cutter for wood concrete Equipment for wood concrete
Today, some foreign manufacturers produce wood concrete based on calibrated softwood chips using special grades of concrete. There is a technology for the removal of sugars from organic matter, which “encourage” the decay of wood, special methods for drying wood chips. Special additives are used that increase the strength and durability of wood concrete, improving its consumer properties. So the initial advantages of wood concrete - the availability of components and environmental friendliness - can be supplemented with new ones. It is difficult to make high-quality wood concrete with your own hands, but it is quite likely. You can buy high-quality wood concrete at a price of 3000 - 3400 rubles / m3.
In our country, rich in forests, wood concrete can be an excellent material for low-rise individual construction.
Sawdust concrete and wood concrete blocks are a lightweight building material with good thermal insulation characteristics. They are used for the construction of private houses, outbuildings and fences. Sawdust concrete and wood concrete can be bought ready-made or made by hand. For manufacturing, you will need the same components as for standard concrete blocks, but with the addition of sawdust or wood chips. They can be both structural and thermal insulation.
For blocks of sawdust concrete, you will need cement, sawdust, sand, quicklime and water. Portland cement is taken at least grade M300. Sawdust is better to use softwood, as they are less prone to decay. If they are old or obtained from other wood, then they must be prepared. Treat with antiseptic agents, for example, a solution of calcium chloride, and dry.
The density of sawdust and cement blocks depends on the proportions of the components. The more Portland cement, the stronger the material, but the worse the thermal insulation properties. This increases resistance to low temperatures, moisture and reduces the likelihood of corrosion in reinforced blocks.
If you add more sawdust, wood concrete blocks will retain heat better, but it cannot be used for the construction of load-bearing structures. Due to the small amount of cement in the composition, it will have weak strength. Therefore, it can only be used as thermal insulation of the finished structure. At the same time, the laying does not require the arrangement of an additional foundation, since it has a light weight.
Blocks from a mixture of cement and sawdust are used for the construction of load-bearing and internal walls of buildings, enclosing structures, for the reconstruction of already rebuilt structures, as well as for the insulation of houses and basements.
Positive and negative characteristics
The advantages of sawdust block material (they are confirmed by the numerous reviews given in the material about):
- easy to process - sawdust concrete can be cut with a regular hacksaw and drilled, just like aerated concrete or foam concrete;
- has good adhesive characteristics - when processed with adhesives, the finish coating is securely fixed to it;
- good thermal insulation properties;
- low combustible - with the right manufacturing technology, sawdust concrete is able to withstand direct exposure to fire for about three hours (if the amount of sawdust does not exceed 50% of the total volume);
- environmentally friendly;
- soundproof;
- simple masonry;
- long service life.
Sawdust concrete acquires fire resistance property as a result of enveloping sawdust with a cement-sand mixture. Compared to concrete with expanded polystyrene granules, sawdust blocks are more fireproof.
The disadvantages include a long time of curing. After manufacturing, building blocks with a thickness of 20 cm are left for 3 months for complete hardening. Only after this period, you can start laying them. Sawdust concrete has poor resistance to water. Therefore, after the construction of the house, a vapor barrier should be equipped to protect it both from the inside and outside of the building.
How to do it yourself?
There are many technologies for making blocks from sawdust. Not only cement, but also gypsum or clay can be selected as a binder. But if the block material will be used for the construction of loadable structures (walls), then Portland cement is taken. To prepare the solution on your own, it is recommended to use a concrete mixer, since a completely homogeneous consistency is required.
According to the technology established in accordance with GOST, in order to make high-quality blocks, it will be necessary to mix the components in the following proportions - 1 part of cement, 1 sawdust, 3 sand and 50% of the volume of binder water. Calcium chloride is taken 40 times less than the amount of cement powder. That is, 20 kg of Portland cement M400 will require 20 kg of sawdust, 59-60 kg of sand and 10 liters of water. Additionally, 0.5 kg of calcium chloride is poured. In percentage terms, sawdust should make up almost 55% of the volume of the entire solution, sand - 26%, cement - about 12%, water - 7%.
Sand is used in medium or coarse fractions. At the same time, about 10% fine fraction is added. Water is poured only clean. Best of all drinking or rain, the main thing - without impurities and dirt.
To make the blocks yourself, you will need forms in which the mixture will fit. It is recommended to make them collapsible so that it is more convenient to pull out the finished material. It can be built from boards with a thickness of 20 mm. Inside, they are covered with sheets of steel so that moisture from the solution is not absorbed into the wooden case. In addition, thanks to the metal, the block material can easily be separated from the mold.
When assembling a box for sawdust concrete or wood concrete blocks, it should be borne in mind that after drying they decrease in size. Therefore, the form must be made 10% larger than the required size of the material. If there are blocks with voids, for example, round ones, then roofing rolled into a tube is placed in the box in advance.
Manufacturing technology: sawdust is sifted through a sieve and mixed with Portland cement and sand. Water gradually pours in. To check the quality, the solution is squeezed in a fist. It should crumple into a ball, water should not flow out. If drops are noticeable, then it is mixed incorrectly. After preparation, the composition must be spent within one and a half hours. The mixture is placed in a mold. Every 20 cm it is rammed to compact and remove air. After filling, everything is left for 4 days. After that, it can be disassembled and stacked block building material in a dry and ventilated room for further hardening.
Peculiarities
For wood concrete blocks, not sawdust with sand, but only wood chips are used, cement and various additives are also needed that improve other characteristics. Compared to sawdust concrete, this material has even better thermal insulation properties. It is also lightweight, frost-resistant and non-flammable. The blocks are environmentally friendly, they are easy to cut and process.
For self-production of such blocks, you will need molds. The solution is mixed in a concrete mixer. To make arbolite blocks, the components are mixed in the following proportions: 3 parts of cement, 3 - chips and 4 - water. First, chips are poured into the concrete mixer and water is poured (not all at once, only to a semi-liquid state). Liquid glass is added (1% of the total volume). After the consistency has become homogeneous, Portland cement M400 is poured in and the remaining water is poured in.
Once the solution is thoroughly mixed, it is placed in a mold for wood concrete blocks. Every 15-20 cm, the mixture is rammed. After a day, if the material has hardened, it is removed from the molds and left to gain strength. Blocks can be used after 2-3 weeks.
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 sawdust concrete.
No matter how similar in composition to each other arbolite and sawdust concrete - there is a difference, and it is, at times, significant.
We will not analyze the differences, we will consider in detail only the sawdust concrete itself.
There are types of sawdust concrete:
- heat-insulating(average density from 400 to 800 kg/m3);
- structural(average density from 800 to 1200kg/m3).
Like any other concrete, sawdust concrete gains strength best in heat and humidity, since moisture does not evaporate quickly and goes to the formation of cement stone.
pros
The main advantages of sawdust concrete are:
- Cheapness of the main components.
- Ease of manufacture.
- The durability of buildings.
- Environmental friendliness.
- Excellent thermal protection.
- A method of manufacture and application developed over decades of use.
Minuses
There is only one main disadvantage: not all sawdust will fit for this material. If, in the case of sugar, they were removed from the chips during resting, 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 sugar decomposition strongly affects the cement itself inside the block.
Manufacturing
In the process of producing sawdust concrete, it is important to take only the most suitable sawdust from those types of wood that have minimum sugar content. Optimal contenders for the second life of waste in sawdust concrete:
- Pine;
- Birch;
- poplar.
Larch, despite the high characteristics of density and strength is in the last place with the highest sugar content.
If in spruce the beginning of strength development begins two weeks after setting, then the end occurs somewhere on the fortieth day after manufacture. But for larch, this period is much longer: from thirty days at the beginning of curing to one hundred and forty at the end.
All works on monolithic sawdust concrete should be done in the spring to be finished by autumn. Due to the released sugars, it is better to bring the sawdust to the condition in the fresh air, including watering the sawdust with water in order to wash away the remnants of sugar breakdown.
A couple of washes with water will already provide the sawdust with an acceptable condition for use in the sawdust concrete manufacturing process. Sawdust structure when stored in bulk, it will prevent the processes of decay and combustion from starting. Since they are not compressed, there is no need to be afraid of moisture.
Compound
Any brand of sawdust concrete contains:
- cement;
- sand;
- slaked lime;
- sawdust.
Differences in proportions observed only in the ratio of the components of the mixture.
Each brand of sawdust concrete has its own proportions.
Components
We prepare sawdust concrete with our own hands. The proportions of the components per 1 m3 of the finished mixture will be displayed in the form of a table:
As you can see, with an increase in the amount of cement, the purpose of the blocks is more reduced to the construction of non-residential buildings. This is due to the change in the coefficient thermal conductivity of blocks, nullifying all efforts to heat the building. When using blocks of the M10 brand, the coefficient is 0.21, which is a very good indicator.
For the M15 grade, this coefficient is 0.24, which is caused only by a slight increase in the requirements for strength, respectively, and an increase in the amount of cement to obtain a durable block for the construction of a two-story house. For the M25 block, the coefficient is already almost 0.39, which is two times higher than that of 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.
Proportions
The proportions of sawdust concrete are shown in the table:
In terms of volume, this means the following. In the manufacture of sawdust concrete:
- Marks M10:
- cement 0.5 buckets;
- a little more than 1 bucket of sand (a bucket with a slide);
- sawdust a little more than 3 buckets.
- Marks M15:
- cement a little more than 0.5 buckets;
- sand 1.5 buckets;
- sawdust almost 4 buckets.
- Marks M25:
- cement 0.5 buckets;
- sand a little less than 1.5 buckets;
- sawdust 3 buckets with two slides.
It is important to follow just such a recipe, because it was worked out for decades, much earlier than wood concrete. The lack of progression in quantity and proportions should not be embarrassing. In each case, the components work differently.
Hydrated lime as a component is used both as a means of sawdust desaccharification, and bypassing this stage, by introducing the required amount of fluff into the mixture.
Preparing the mixture
Surprisingly, the easiest way to prepare the mixture is by hand. When preparing sawdust concrete with your own hands, ordinary concrete mixers will not work. Due to the lightness of some components, they run the risk of remaining on the walls of the concrete mixer, or simply floating on top of the water. Any loading order.
You can first:
- dilute cement in water;
- add sand, sawdust and lime.
Another variant:
- mix sawdust with lime;
- add sand and cement;
- dilute with water.
No matter what other people say, there is absolutely no difference in which option to choose.
As a result of the work, a homogeneous mixture is formed, in the structure of which there is sand with cement. These two components form cement stone. The lime neutralizes the sugars as they are released from the sawdust, and the sawdust itself is the filler. Lightweight concrete classic.
Machine kneading sawdust concrete functionally possible if there is a forced-type mixer, 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 they are no longer afraid of water.
Sawdust concrete based on gypsum binder
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 setting speed of gypsum in combination with water, since these moments have already found a popular solution.
The problem is solved by adding an ordinary detergent to the water, and it, as you know, dispenses water in a dosed manner 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.
Until now, the dispute has not been put to an end - is it possible to build external walls from gypsum-based blocks.
According to some reports, with proven technology (on hand) and when protecting blocks from atmospheric influence, it is quite possible to use these blocks for building exterior walls. You can definitely build internal ones.
The only question is the price for the binder, but in terms of the volume of sawdust and setting strength, we can say that the costs will be slightly higher, and the rate of curing is four to five times higher.
About sawdust size
The size of the sawdust does not matter if there is enough binder.
As a rule, sawdust is taken from a sawmill, and the differences in sawdust from a band sawmill and a circular sawmill are so negligible that they are not taken into account at all.
Here, the chips from the cylindering and calibrating machines will no longer work.
A homogeneous mixture will not work if there are fractions in one volume that differ from each other in volume by several hundred times.
Of the features of the process - it is important to knead so that when a lump of the mixture was picked up and squeezed with his hands, water would 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 the hands.
Including 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 with a shovel:
The use of sawdust concrete
A truly folk building material, as it is the most affordable of materials on the complexity of production. Perhaps people are noticing for themselves a wave-like interest in such materials. If earlier sawdust concrete was a good option for the whole country, then with the wave of Western marketing, people in pursuit of fashion have moved away from a reasonable choice.
It is only now that many have begun to turn to environmental friendliness and practicality building materials, and not something that was designed for completely different climatic conditions. Successfully erected from sawdust concrete:
- houses up to three storeys;
- garages;
- sheds;
- outbuildings;
- technological buildings.
Like any moderately hygroscopic material, sawdust concrete needs an exterior finish, 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, do not be embarrassed by the presence of sawdust in the blocks. A popular insulation that was produced in Germany at the beginning of the last century - ecowool - is generally made from what is collected in landfills.
Therefore, it is still worth figuring out what is more environmentally friendly - sawdust concrete with natural ingredients, or ecowool with hyper-content of bromine salts.