Wood concrete: characteristics and purpose of building material. Wood concrete - this material is the future in low-rise construction Material for construction wood concrete

Arbolite has been used in construction for quite some time. The requirements for the material are established in GOST 19222*84.

GOST 19222-84. Wood concrete and products made from it. General technical conditions.

For the production of wood concrete, a binder (cement) component, organic fillers and additives are used to adjust the characteristics. The material is used for the construction of structures for various purposes.

The composition of the mixture (content of cement, water and chemical additives) for the manufacture of the material may vary depending on the type and fraction of organic matter.

In accordance with the current standard, manufacturers produce two types of wood concrete.

Table. Types of material.

Material	Density, kg/m3	Compressive strength, grade
	400...500	M5, M10, M15
	500...850	M25, M35, M50

The scope of application of structural wood concrete is the construction of low walls (2, 3 floors) and partitions, installation of lintels over openings and armored belts. Thermal insulation material needed for thermal insulation of walls and ceilings, as well as noise protection. Construction load-bearing structures from products made of wood concrete having a density below 500 kg/m 3 is prohibited.

Important! As the density increases, the thermal insulation efficiency decreases.

The relative humidity inside arbolite buildings should not exceed 60%. The presence of an aggressive gas environment is also not allowed.

Important! When ensuring the protection of structures made of wood concrete (in accordance with building codes) from corrosion restrictions concerning environment, can be removed.

Wood concrete is used to produce blocks, which are most in demand among consumers, and panels (they are mainly used for insulating floors).

What characteristics do wood concrete blocks have?

The thermal conductivity coefficient of the material, depending on the organic filler, can be:

0.08...0.17 W/(m×°C) - for products containing wood;
0.07...0.12 W/(m×°C) - for products with other types of filler.

This thermal insulation ability of the material allows a wall just 30 cm thick to resist the penetration of cold just as effectively as a meter-long brick wall.

When shipped to the consumer, wood concrete should not have a moisture content exceeding 25%.

The frost resistance of the material can be F 25 or F 50. In terms of resistance to biological damage, it belongs to group V. Wood concrete can withstand fire for up to 90 minutes.

Arbolite blocks may be reinforced. In this case, welded mesh or rod steel with a coating that protects against corrosion is used. The thickness of the concrete layer to the reinforcement should not be less than 1.5 cm. Embedded parts can also be installed in the wood concrete.

Prices for construction metal reinforcing mesh

Construction metal reinforcing mesh

Requirements for mixture components

The standard defines standards regarding the raw materials used in the production of blocks.

Important! Many people use sawdust and sand as components in the manufacture of blocks. Sawdust concrete and wood concrete are different materials.

Astringent component

Arbolite mixture can be produced from the following types of cement:

Portland cement;
Portland cement with mineral additives;
sulfate-resistant cement (not pozzolanic).

Brands of approved raw materials:

for heat-insulating blocks - from M 300;
for structural products - from M400.

Prices for cement and basic mixtures

Cement and base mixtures

Organic filler

This component, the content of which in the mixture reaches 80%, is subject to high demands.

Types of filler used in the manufacture of wood concrete:

chopped wood;
rice straw (finely chopped);
flax or hemp fire.

Most often, waste from logging and wood processing enterprises is used as a filling component. To make wood concrete, you need needle-shaped chips. As a rule, it is obtained from croaker.

The wood mainly used is spruce, pine, birch, aspen or poplar. It should be noted that in coniferous trees contains less sugars that prevent cement from hardening and cause fermentation of organic matter in the finished product. The size of such filler should not exceed 4 x 1 x 0.5 cm. The optimal aspect ratio is 1:5. When sawdust is used as a component of the mixture, the strength of the blocks is significantly reduced.

Wood chips are almost impossible to buy in finished form. Manufacturers must resolve the issue of raw materials themselves, namely, install wood grinding equipment.

Important! Raw materials should not contain more than 10% bark and more than 5% pine needles and leaves.

The highest quality filler is obtained as a result pre-treatment lump waste on chippers and subsequent grinding in hammer crushers. The resulting raw materials must be dried for a month; they cannot be put into production immediately. Often material with wood waste in its composition is called wood concrete or chipped concrete.

When using other organics, you need to pay attention to the length of the particles. It should not be more than 4 cm.

The filler should not be contaminated with mold or have foreign inclusions.

Important! To prevent rotting, many manufacturers treat raw materials with a lime solution (15%).

Supplements

The introduction of chemical additives into the composition can improve some of the characteristics of the material. The types of substances are established in GOST 24211*2008.

Additives for concrete and mortars. General technical conditions.

Table. Types of chemical additives for the production of wood concrete blocks.

Some added additives can have a complex effect on the material.

Video - Production of wood concrete and wood monolith

Dimensions of wood concrete blocks

The most popular products among consumers have the following dimensions:

500 x W00 x 200 mm;
500 x 250 x 200 mm;
500 x 250 x 150 mm;
500 x 250 x 300 mm;
600 x 300 x 200 mm.

Wall blocks can also have dimensions of 400 x 300 x 200, 400 x 250 x 350 and 400 x 400 x 200 mm, and partition blocks - 300 x 150 x 200 and 500 x 150 x 250 mm.

Advantages and disadvantages of arbolite blocks

The manufacturing technology and composition of the material endows it with many qualities useful for construction.

Environmental safety for the consumer (the units do not emit harmful to humans and animal substances).
Low thermal conductivity (lower than products made from other types, with the exception of some types of foam concrete).
Excellent sound insulation (4 times higher than that of ordinary brick).
Non-flammability.
Decent frost resistance.
Sufficient strength, which is guaranteed by tightly bonded chips.
Light weight of the material, facilitating the installation process and reducing the load on the foundation.
Slight shrinkage (up to 0.5%).
Ease of processing, allowing you to cut products and install fasteners in them.
Resistance to cracking under load.
No need to use plaster mesh when finishing walls made of blocks.

However, it is necessary to take into account some disadvantages of wood concrete blocks:

high moisture absorption (up to 85%), which has to be combated with waterproofing;
poor geometry, which requires increased flow masonry mortar and leads to heat loss;
high cost of finished products;
not very aesthetic appearance material requiring mandatory finishing;
when laying, a significant part of the solution gets into the cavities, which are heat insulators (but at the same time the structure becomes stronger).

Before purchasing products, it is necessary to check the documentation, otherwise there is a possibility of running into products made in an “artisanal” way, which often leads to a decrease in their quality.

As a rule, problems with geometry are caused by the stripping of blocks immediately after pressing. The elastic mixture expands, as a result of which the deviation in size can be up to 2 cm.

A number of shortcomings are eliminated in a new type of product - an arbolite block with an outer layer of foam concrete. In this case, an organic-based substance should be used as a foaming agent in order to preserve environmental safety products.

Manufacturing technology of arbolite blocks

The diagram of the production line for wood concrete products is shown in the illustration.

The production cycle looks like this:

Organic filler is loaded into a horizontal twin-shaft mixer;
water with aluminum sulfate is added (to neutralize sugars in organic matter) and additives;
after this, Portland cement is introduced;
the mixture is stirred for three to five minutes;
the mass is loaded into molds treated with emulsol for vibration compaction;
You cannot immediately dismantle finished products. The blocks must be in forms, otherwise it will not be possible to achieve good geometry. They are delivered a day after production;
for hardening the products are installed in warm room for 10 days. Some manufacturers use a steaming chamber to ripen their products. This increases the strength of the finished blocks;
finished products are packed on pallets and sent for storage.

The blocks can be used for construction approximately three weeks after production. When using additives that accelerate hardening, this period is reduced.

Important! Many manufacturers for lubrication internal surfaces forms use waste machine oil, which, naturally, is cheaper than emulsol. However, it can leave oil marks on the blocks, which can lead to problems when finishing walls (the coating may not lie on the surface).

Making blocks yourself

You can also make blocks yourself. However, you should be prepared that the result does not always live up to expectations. When manually tamping, it is difficult to achieve the required strength of the material.

The most important thing when making blocks with your own hands is to stock up on organic filler. It is convenient when it is possible to negotiate its delivery at a woodworking enterprise. Installing a crusher on your farm to produce a small number of products is not very justified.

For the work process you will need a concrete mixer and split molds.

It would be better if they were metal. Wooden structures It is recommended to line the inside with linoleum. This will make it easier to remove finished products.

Video - Mold for preparing wood concrete blocks

The block production technology is not complicated.

Step 1. The filler is being prepared. It must be cleared of foreign inclusions.

Step 2. The filler is loaded into the concrete mixer, the unit is turned on.

Step 4. Water mixed with calcium chloride is poured into a running mixer and additives are added. The wood chips should be evenly saturated with water and become dark.

Step 5. Cement is added. Proportions of components (by weight): 1 part water, 6 parts wood chips and 1 part cement. Calcium chloride needs 2% by weight of cement. Mixed until homogeneous (there should be no chips left that are not covered with cement), the mass should be crumbly, but plastic.

Video - Kneading wood concrete

Step 6. The mass is unloaded from the mixer.

Step 7 To produce blocks, metal molds are used, the removable bottom of which is covered with film so that the concrete does not stick to the base. It is more convenient when the matrices can be disassembled. This makes it easier to remove the block.

Step 8 The mixture is poured into the mold in layers. Each layer is carefully compacted.

Step 9 The next day the block is removed and sent to dry. In this case, the product should be covered with polyethylene.

For laying blocks, a cement-sand mixture or adhesive composition, which is a little more expensive. It is not recommended to use DSP when constructing the walls of a residential building, since cold bridges form in the seams. Glue designed for working with cellular concrete is much more energy efficient. You can also use a mixture with perlite, which is called “warm”.

How is wood concrete blocks laid?

Step 1. It is necessary to lay it on the foundation so that moisture from it does not penetrate into the blocks. For this, roofing felt (2 layers) is most often used. The width of the material should be approximately 10...15 cm greater (on each side) than the thickness of the future walls.

Step 2. The installation of walls begins with corner blocks. Masonry mortar is applied. For this you will need a trowel. The thickness of the layer is approximately 6 mm (part of the composition will go into the cavity, leaving a 3 mm seam). Correct installation is checked by level. If necessary, adjust the block using a rubber mallet.

Step 3. Between blocks (with outside) the string is pulled. It will serve as a level for mounting the entire row.

Step 4. Masonry mortar is applied to the vertical end face of the block. The second product is installed tightly. Then its vertical is treated with glue and a new block is laid.

The procedure continues until the entire first row is completed. If you need to adjust the size of the block, you can use any saw: manual, electric or with a gasoline engine.

Prices for the popular range of petrol chain saws

Chainsaw

It is necessary to immediately treat the cut site (chips without cement) with an antiseptic composition (any suitable for wood processing). After finishing the laying of the first row, you need to take a break for several hours to allow the mortar to set.

Step 5. Reinforcing mesh is laid on the blocks of the first row.

It will need to be used every 4 rows of masonry.

Step 6. The laying of blocks continues with the application of masonry mortar to the horizontal surface and ends of the products. They are installed with dressing. Periodically, the horizontal and vertical structure of the structure should be checked with a level.

As you can see, the use of wood concrete blocks in construction is not particularly different from the masonry of other types of products.

Wood concrete blocks are a worthy alternative products made of foam, gas or expanded clay concrete that are familiar to us. Their performance characteristics allow the material to be used in the construction of low-rise buildings for any purpose.

Video - Laying wood concrete blocks

Definition of wood concrete

Nowadays there is a huge variety of building materials. This article will consider a material that represents a synthesis of seemingly incompatible components - wood and concrete. So, what is wood concrete?

According to GOST 19222 84 wood concrete and products made from it, wood concrete is a building material based on cement, organic fillers (mainly wood chips) and chemical additives, including those that regulate porosity. The term arbolite comes from the Latin arbor - tree and the Greek lithos - stone. But that’s exactly what they began to call it in the 70s, when GOST 19222 73 was created. Before that, it was called a cement-wood composition or simply wood concrete.

Photo Wood concrete block

GOST 19222 84 allows the use of components such as wood shavings, flax and hemp bonfire and crushed rice straw. But manufacturers prefer to use wood chips different breeds wood, because it is the high proportion of wood chips that gives the finished product such properties as thermal insulation and sound insulation. The majority of manufacturers produce wood concrete from high-grade cement and wood chips, the dimensions of which are the most important criterion during production quality product. Chips are produced on special chipping machines. The chips contain sugars and other substances that prevent the chips from adhesion to cement; to eliminate this property, they are treated with mineralizers (calcium chloride, slaked lime, aluminum sulfate, etc.). The ratio of components is selected depending on the desired strength class. The main component is wood chips; up to 90% of it can be included in wood concrete. Such a high content of wood filler results in excellent thermal insulation properties. Plus, products made from wood concrete “breathe” just like those made from wood.

Species

According to GOST 19222 84, wood concrete, depending on density, is divided into:

thermal insulation - with an average density of up to 500 kg/m3;

structural - with an average density of over 500 to 850 kg/m3.

Thermal insulation is used as non-load-bearing partitions, in the construction of light one-story buildings, as insulation.

Structural is used for the construction load-bearing walls V low-rise construction(up to 3 floors).

Arbolite, depending on its compressive strength, is divided into classes:

B0.35; B0.75, B1 - for heat-insulating wood concrete;

B1.5; B2; B2.5; B3.5 - for structural wood concrete.

The compressive strength indicator is characterized by brands:

M5, M10, M15 - for heat-insulating wood concrete;

M25, M35, M50 - for structural wood concrete.

Specifications

The main technical characteristics of wood concrete are presented in the table

Indicator	Filler – wood chips
Average density, kg/m3	500 - 850
Compressive strength, MPa	0,5 – 3,5
Bending strength, MPa	0,7 – 1
Modulus of elasticity, MPa	250 – 2300
Thermal conductivity, W/(mS)	0,08 – 0,17
Water absorption,%	40 - 85
Frost resistance, cycle	25 – 50
Shrinkage,%	0,4 – 0,5
Fire resistance	0.75 – 1.5 h
Sound absorption, 126 – 2000 Hz	0,17 – 0,6
Biostability	5 group

Let's now take a closer look at these characteristics.

Density is a fundamental factor in the construction of structures. According to GOST 19222 84, in the production of wood concrete, instead of wood chips, you can use such fillers as hemp and flax, crushed cotton stalks and crushed rice straw. The average density of wood concrete, depending on the type and class, as well as the type of filler, is shown in the table.

Type of wood concrete	Compressive strength class	Axial compressive strength grade	Average density, kg/m3, of wood concrete per
			chopped wood	flax fire or crushed cotton stalks	hemp bonfire	crushed rice straw
Thermal insulation	B0.35	M5	400-500	400-450	400-450	500
	B0.75	m10	450-500	450-500	450-500
	B1.0	M15	500	500	500
Structural	B1.5	-	500-650	550-650	550-650	600-700
	B2.0	M25	500-700	600-700	600-700	-
	B2.5	M35	600-750	700-800	-	-
	B3.5	M50	700-850	-	-	-

Comparison of density with other building materials:

Although the density of wood concrete is not high, thanks to this, the finished structure will weigh much less than a brick one. And if the weight of the building is light, then you can save on the foundation.

Strength means the threshold value of impact above which the material is destroyed. For example, a cube of wood concrete 150*150*150 (mm) with a density of 600 kg/m3 will withstand a load of more than 8 tons. Important Features are bending strength (0.7 - 1 MPa) and elasticity (up to 2300 MPa). Thanks to this, wood concrete stands out from other building materials. Blocks from cellular concrete or brick are brittle materials.

One of the main advantages can be called such a characteristic as the thermal conductivity of wood concrete. It was from it that, in the early 60s, at the Molodezhnaya station in Antarctica, three service buildings and a canteen were built. Moreover, the thickness of the walls was only 30 cm. A wall made of arbolite with a thickness of 30 cm corresponds to thermal insulation brick wall 90 cm thick, and wooden - 50 cm. Along with thermal conductivity, wood concrete has good heat capacity, i.e. the ability to absorb heat when heated and release it when cooled. The heat capacity of wood concrete is comparable to wood.

Photo Arbolit in Antarctica. Molodezhnaya station.

Despite the high water absorption rate, wood concrete is non-hygroscopic, i.e. cement and wood chips treated with mineralizers do not absorb water well. Water poured onto the block passes through it freely, but is not absorbed. The remaining moisture evaporates over time. Therefore it is necessary to do facade finishing.

Moisture in porous materials expands when frozen and leads to destruction of the material. The cycle of freezing and thawing without deteriorating the properties of the material is called frost resistance and for wood concrete it is 25-50 cycles. In fact, this means that a structure made of wood concrete will not change its performance characteristics for more than 50 years. This is due to low sorption moisture absorption. And if you perform façade finishing and thereby prevent moisture from entering the material, this figure will increase significantly. This characteristic of wood concrete is higher in comparison with foam concrete, for which it is equal to 20 cycles.

Shrinkage implies a change in the volume and linear parameters of the material, which can result in cracks in the walls. Wood concrete is almost not subject to shrinkage (0.4 - 0.5%), in contrast to ordinary timber, whose shrinkage coefficient reaches 8%. But nevertheless it is recommended to produce interior decoration 4 months after the production of the block and no earlier than 2 months after the completion of the construction of the house box under the roof.

Fire resistance is the ability of a material to maintain its performance characteristics in a fire. Despite the fact that wood concrete contains up to 90% wood chips, it has good fire resistance and can withstand the burning of an open flame at a temperature of 1000 C for up to 1.5 hours. Also, it itself does not burn, does not smolder and does not spread fire.

Arbolite blocks have good sound insulation, which is superior to wood and brick. In the range from 126 to 2000 Hz, the sound absorption coefficient is 0.17 - 0.6. This property of wood concrete is superior to many other building materials. For example, for brick this indicator is less than 0.04.

Arbolite belongs to group 5 biostability. But it is worth considering that wood chips are dried for several months before production. When cement and water are added, the wood chips are enveloped in cement laitance and isolated from the environment. Therefore, unlike wood, wood concrete does not rot and is practically not susceptible to biological contamination (fungi, mold) and the effects of chemicals.

The practice of using wood concrete in construction proves its durability. The buildings at Molodezhnaya station in Antarctica are still functioning. Below is a video of a house built in 1986, which confirms the durability of wood concrete. Judge for yourself.

Application

The building material wood concrete is used quite widely: as panels and blocks for external and interior walls; floor slabs and coverings; partition slabs; thermal insulation boards in enclosing structures; soundproofing boards; monoliths, etc. Due to its low weight, a lightweight foundation can be used, which has a positive effect on the price of the entire construction project as a whole. Basically, blocks are used in construction, which can be different sizes. The most common blocks for load-bearing walls are 300*200*500, for partitions 200*200*500.

Experience in the use of wood concrete has shown that its performance when used in enclosing structures is not inferior to, and in some cases superior to, concrete based on mineral porous aggregates, including the widespread expanded clay concrete. In terms of thermophysical properties, the use of wood concrete panels in comparison with expanded clay concrete panels makes it possible to reduce the thickness of building walls by more than 1.5 times. Wood concrete has also proven itself well for the construction of poultry and livestock farms, garages, and utility rooms. Despite the average moisture resistance, it has low hygroscopicity, due to which it dries quickly. This allows it to be used in the construction of a bathhouse. Wood concrete has a relatively low density (up to 850 kg/m3), so it can only be used in low-rise construction (up to three floors). But for the construction of a cottage, summer house, bathhouse or outbuildings this does not matter much.

Conclusion

Specifications wood concrete, make it a worthy building material. It has excellent thermal insulation properties, so the house will be warm in winter and cool in summer. It does not transmit sound well, does not burn, does not rot. Due to its elasticity, it does not shrink, therefore, there will be no cracks or distortion of the geometry in the structure. Due to the low weight, the load on the foundation is reduced, so it can be made light. Arbolite is environmentally friendly pure material, since it consists of 90% wood chips. Many years of practice in the operation of buildings and structures made from it proves its durability.

Arbolit is one of the representatives lightweight concrete and is used in the construction of buildings and structures for any purpose. Construction country houses, cottages and outbuildings will become a budget event if you choose wood concrete as the main material. It is used in the form of blocks for constructing external load-bearing walls and internal partitions, and also made from it various slabs and panels.

density: 600-650 kg/m3;
compressive strength: up to 1 MPa;
bending strength: up to 1 MPa;
thermal conductivity: 0.07-0.17 W/mhK;
frost resistance: 50 cycles;
sound absorption: 126-2000 Hz;
moisture absorption: 40-85%;
shrinkage: 0.5%.

Block composition

Wood concrete is made from wood filler, binder, chemical components and water. Wood filler is present in the form of waste from wood processing (spruce, fir, aspen, pine, birch, poplar) and crop production (flax, rice straw, cotton stalks). Very large particles increase in volume after getting wet, this can lead to subsequent destruction, while small ones will take on more cement mortar. Their optimal size is 40x10x5 mm. Its chemical activity is the main disadvantage, therefore the introduction of wood from freshly cut trees into the composition of wood concrete blocks is highly not recommended.

The most popular organic composition is wood shavings and wood chips in a ratio of 1:1 or 1:2. In addition to sawdust, you can take flax waste. The fire should be needle-shaped, 2-5 mm wide and 15-25 mm long. The presence of foreign particles, signs of mold and rot in the composition of raw materials is unacceptable, and in winter period- ice and snow.

The sugar in flax destroys cement, so it is necessary to introduce chemicals into the wood concrete. To improve the quality of lightweight concrete, the fire needs to be treated with lime milk (2.5 kg of lime dissolved in 150-200 liters of water per 1 m3 of filler), left for 2 days and stirred every day. The use of this technology will reduce cement consumption to 100 kg per cubic meter of concrete. Another way to neutralize sugar is to place the fire in the fresh air for 3-4 months, which will give the blocks additional strength.

The mineral binder in the mixture is Portland cement grades 400, 500 and higher. To calculate the amount of cement per 1 cubic meter of wood concrete 16, you need to increase its value by 17 times. It turns out: 16x17= 272 kg. Chemical additives determine the properties of the wood concrete block. Regardless climate zone, where a structure or building from this will be erected building material, their inclusion in the composition is mandatory. Thanks to the ability to neutralize sugar, the chemicals will make it possible to use wood fillers without processing it.

Such additives can be: soluble glass, K 2 SO 4, slaked lime and CaCl 2. Aluminum sulfate, combining with sugars, neutralizes their effect, thereby increasing the strength of the finished product. Chemicals are used both separately and in combination: Al 2 (SO 4) 3 and CaCl 2 in a 1:1 ratio, slaked lime and soluble glass - 1:1. Before use, they are diluted in water, and then combined with wood concrete mixture. The total mass of additives in 1 cubic meter should not exceed 4% of the total weight of cement.

Arbolite grade 30 includes additives: Al 2 (SO 4) 3 and CaCl 2 – 1:1; Na 2 SO 4 and CaCl 2 - in the same ratio and in an amount of 4% of the total weight of cement. Na 2 SO 4 and AlCl 3 – 1:1 in 2% by weight of the binding part. When producing wood concrete, the proportions per 1 m3 of batch must be strictly observed.

Manufacturing technology

Arbolite blocks can be made with your own hands. If you need a large number of them, purchase a concrete mixer, a tamper, molds and a drying oven. Budget option involves making your own molds and purchasing a mixer components solution. The proportions of components in arbolite blocks were discussed above, therefore:

1. Gradually pour wood filler into a concrete mixer and fill it with water and chemical additives, mix everything thoroughly.

2. Pour in Portland cement and, gradually adding water, mix everything again.

3. Process the form inside lime mortar.

4. Place the finished mixture into molds, compacting each layer tightly. The volume is filled to a level of 2 cm from the edge.

5. Place the plaster mortar on the free space. Level the surface with a spatula.

The resulting block should be in the mold for about 24 hours, after which it is removed and placed under a canopy for two weeks for gradual drying.

As you can see, the technology for making wood concrete blocks with your own hands is quite simple, and compliance required proportions will allow us to obtain a building material that fully complies with its technical characteristics.

Advantages and disadvantages of blocks

high sound and heat insulation;
increased fire resistance;
resistance to mold and rot;
has sufficient strength;
there is no need for a powerful foundation;
ease and simplicity of installation;
environmentally friendly, low cost.

Possessing a certain moisture permeability, arbolite structures can be used in dry conditions. In all other cases, the walls must be protected from moisture insulating material. When constructing walls in basements and ground floors the use of arbolite blocks is not recommended. Impact protection atmospheric precipitation This is done by painting them hydrophobically or plastering the walls on both sides.

Before you start making wood concrete blocks yourself, you need to correctly calculate and think about everything. If the production technology is strictly followed, houses made from this building material will be comfortable, warm and inexpensive.

Wood concrete or wood concrete is a type of lightweight concrete with a somewhat unexpected filler - wood chips. Its properties differ markedly from the more familiar sawdust concrete, and in favor of wood concrete.

He found a wide variety of applications. About the composition of wood concrete, its proportions, advantages and disadvantages of blocks and wall panels, price per cube, owner reviews will be discussed in this article.

Concrete, in general, consists of filler, binder and any additional ingredients. Concrete differs from conventional building material in the way it is used: it is placed in a mold or formwork in liquid form and, when dried, acquires its design strength.

Wood concrete differs from conventional types of concrete in composition and, accordingly, in some qualities.

The video below provides a review of the pros and cons of wood concrete:

Description and features

filler– wood chips, which are quite strictly limited in size, as well as crushed rice straw, flax seeds, cotton stalks, and even pine needles and bark;
astringent– the corresponding brand. This depends on the expected strength of the material, but not lower than M300;
chemical additives– provide best connection components, rapid hardening and so on. Mainly chloride salts of potassium, calcium, aluminum are used, as well as “ liquid glass».

The raw material is no less important: the size of the chips is important - no more than 25 mm in length and 10 in width, a certain degree of roughness, the type of wood - spruce, pine, beech, and even the nature of the wood - early or late. If all GOST standards are observed, the material turns out to be porous, “breathable”, but at the same time durable.
The composition of the starting components affects the result to no less extent. For thermal insulation material, the ratio is usually as follows: 1 share of binder, 1 share of wood chips and 1.5 shares of water, or, more precisely, a solution with salts. To obtain a structural material, the proportion of binder increases within certain limits.
During production, it is not the proportions that are regulated, but the resulting properties of wood concrete. If they comply with GOST or TU, then the composition is considered suitable for use.

Pros and cons

Advantages

Like any material, wood concrete has its advantages and disadvantages. Thus, wood concrete is not intended for the construction of high-rise buildings due to its low strength, but it has been used as a heat insulator for a long time and successfully.

Thermal insulation properties are the most remarkable feature of wood concrete. The thermal insulation material has a thermal conductivity equal to 0.08 W/(m*C), that is, it is ahead of any kind of concrete and brick.
In addition, wood concrete is an accumulating material and retains heat: in a house made of wood concrete there are no sudden changes in temperature.
Unlike wood materials Wood concrete is a substance that is difficult to ignite, difficult to burn and produces a minimum of smoke. It can be safely called fireproof.
Arbolite has very high vapor permeability. Of course, it is inferior to wood in this indicator, but still, it is preferable to build baths from wood concrete rather than another type of stone.
The strength of the material, if we mean structural, reaches class B3.5, which is not too much: buildings no higher than 3 floors can be built from wood concrete. However, it has another valuable property: wood concrete is resistant to tensile loads, which means that when the foundation moves and shrinks, the material is compensated and does not become cracked.
Frost resistance different types wood concrete ranges from class F25 to F50. However, the combination of frost and dampness significantly reduces this figure.
Wood concrete is excellent at sawing, cutting and holds fasteners perfectly. This is an excellent solution for outbuildings.
The material is lightweight, which greatly facilitates construction, especially independent construction.

Flaws

The disadvantages are associated with the advantages of wood concrete.

Water absorption - wood concrete must not be used in the construction of premises in which the humidity will be known to be high - 75%. Wood concrete absorbs moisture by 75–85%, but does not retain it. If you immerse a block in water and then remove it, all the collected water flows out and the wood concrete dries out. This property allows the use of wood concrete in the construction of baths, although the humidity there is even higher. However, the dwelling belongs to premises that are constantly heated, unlike baths, so here the restriction on the amount of humidity continues to apply.
The relative fragility limits the scope of application - in fact, this is low-rise construction and thermal insulation.
The question of the durability of the material still remains open: too little data has been accumulated and too much depends on the quality of the wood concrete.
Wood concrete is not at all a cheap pleasure, as is mistakenly believed. The material made in accordance with GOST has a cost quite comparable to foam concrete, since its production technology is poorly automated.

Species

They produce 2 types of wood concrete:

structural– with a higher cement content and higher density – from 500 to 800 kg/cu m. It is allowed to build self-supporting and load-bearing walls from structural wood concrete. If necessary, the material can be reinforced with mesh and rods;
thermal insulation– with a larger share of chips and lower density – up to 500 kg/cu. m. Partitions can be built from it, and used as a heat insulator for load-bearing walls.

Wood concrete can have two forms of release.

Blocks– finished products of certain sizes. GOST regulates not so much dimensional parameters as deviations from them. In practice, the error in dimensions is much higher, which should be taken into account during construction: the seams between the blocks will be of different thicknesses.

It is produced on the construction site and used immediately: the material cannot be stored. Monolith is most often used specifically for thermal insulation of walls and floors. However, it is also possible monolithic construction small buildings.

Manufacturing a monolith reduces the cost of construction, but reduces the speed: like all other types of concrete, wood concrete needs long term to achieve design strength.

Specifications

The combination of wood chips and cement is not an analogue of wood. This is, nevertheless, concrete and should be considered as a building stone, not wood. Accordingly, materials of different types are assigned a strength class and grade, like any other concrete.

Type of wood concrete	Compressive strength class	Strength grade (axial compression)	Average density, kg/cube m.
Thermal insulation	B0.35	M5	400–500
	B0.75	–	500–650
	B1.0	M15	500
Structural	B1.5	–	500–650
	B2.0	M25	500–700
	B2.5	M35	600–750
	B3.5	M50	700–850

Based on the data provided, the weight of the products, the load on the foundation during construction, the required transport capacity, and so on are calculated.

Wood concrete is produced if we are talking about a finished product in the following forms:

blocks– medium, large, narrow, intended for laying walls;
U-shaped blocks– for window and door lintels, as well as other types of recesses;
slabs– combined with a layer of heavy concrete, since the material itself cannot provide the proper strength. Their length according to GOST should not exceed 4.8 m.

The dimensions of blocks and slabs can fundamentally vary within fairly wide limits upon agreement with the customer.

Production and Application

is a fairly simple technological line, but the process itself, due to the length of the curing period, turns out to be extended in time and quite significantly. In addition, hardening of wood concrete in molds is possible only at a temperature not lower than +12 C, which limits either the production time or increases the cost of the material.

Consists of the following steps.

Receiving wood chips– they use waste from the timber processing industry for production, but with some restrictions. For example, wood species such as larch or poplar are not allowed. In this case, the dimensions of the chips must exactly correspond to GOST, otherwise the quality of the final product will be questionable. The following crushers are suitable for this: disc crushers, rotary knife crushers, shredders, but the best is considered to be a hammer crusher, where the chips are obtained in the required size.
Dosage and mixing– in production, special dispensers are used for this. At self-production The main thing is not to get confused: the composition is determined by weight or volume ratio.
Mixing produced in a cyclic mixing mechanism - a concrete mixer. Because they seize wood fibers and cement is bad, mixing takes at least 10 minutes.
Laying in molds– the finished mixture is fed into molds, metal or wood, by a bunker-stacker.
Tamping- even in industrial conditions does not exclude manual labor. It is important not only to compact wood concrete, but also to settle it, for which purpose the mixture is first pierced with a sharp metal tool, at least with a pitchfork. Then they are compacted using a regular tamper or on a vibrating table.

when insulating walls, floors, and ceilings, both monolithic and block wood concrete are used for this. As a heat insulator, the material is more effective than foam concrete and has much higher vapor permeability.

Popular manufacturers and average cost of production

Wood concrete, although lightweight, is still concrete, and therefore it is more profitable for the builder to contact the nearest manufacturer, if, of course, the quality of its products is really worth a good word. Very often, wood concrete is produced using a rather artisanal method, which significantly affects it and its reputation.

Most often, companies offering the construction of buildings from wood concrete produce it themselves

The EcoDrev Product company is one of the largest manufacturers in Russia, producing more than 1000 cubic meters. The cost of finished blocks depends on the type of material: the price of thermal insulating wood concrete per piece is 4600 rubles. per cubic meter m, and structural - from 5400 to 6200 rubles. per cubic meter m.
The wood concrete products plant offers blocks of various sizes. Average cost products - from 3600 rub. per cubic meter m.
The construction and trading company "Arbolit Trade" produces solid and hollow wood concrete at a price of 5,250 rubles. per cubic meter. The price here also includes delivery of the material.
The Velizh house-building company has been producing wood concrete blocks since 2007. The cost of products is from 3900 rubles. per cubic meter m.
The Vologda wood concrete plant offers structural wood concrete for 4,200 rubles. per cubic meter m.

Arbolite is a building material based on cement and wood chips, which has good technical characteristics

Arbolite is a building material based on cement and wood chips, which has good technical characteristics and differs in its properties from both ordinary concrete and sawdust concrete.

Since wood chips are based on wood chips, the highest requirements are applied to its size and quantity in the mixture, since the quality of the material and its grade depend on them. Before use, wood chips undergo strict control. The most optimal types of wood for the production of wood concrete are pine, beech or spruce.

Even the time of wood harvesting - late or early - plays a big role in the quality of the material - this directly affects its final properties. The dimensions of the chips should not exceed 25 mm in length and 10 mm in width.

The binding component in wood concrete is cement of a grade no lower than M300, since the strength of the finished material depends on the grade. To improve the connection of the components of the mixture with each other and to quickly harden it, various additives are used, such as potassium chloride salts and liquid glass. Wood chips and cement do not mix well, so the wood concrete manufacturing process must proceed without disruption technological process. One of its important stages is long and thorough mixing of both components.

Types of wood concrete and its technical characteristics

At the moment, two main types of wood concrete are produced:

Thermal insulating wood concrete, with a density of about 500 kg/cu.m. m. As the name already implies, this material is used as a thermal insulation layer during construction interior partitions, on which there is no load.
Structural wood concrete. Its density is much higher and can reach 800 kg/cubic meter. m. This is explained by the fact that the amount of cement in it is much higher than wood chips. The technical characteristics of such wood concrete allow it to be used in the construction of load-bearing supports and walls. To give it greater strength, it can be reinforced with mesh or rods.

Wood concrete is available in two types:

Blocks. This is a building material that is completely ready for use and has certain geometric dimensions. Unfortunately, due to the characteristics of wood concrete, there may be errors in its dimensions. Despite the fact that they are regulated by GOST, in reality the inconsistencies can be very serious. This feature must be taken into account when designing and calculating required material. Arbolite blocks can have a U-shaped recess, and can also be large, medium or narrow.
Monolith. Wood concrete of this type is made directly on construction site immediately before installation. The batch after mixing must be used completely. This method is most suitable for creating a thin thermal insulation layer in a room.

Advantages of wood concrete

Good thermal insulation properties. The thermal conductivity of wood concrete is only 0.08 W, which is significantly better than that of concrete or brick.
Fire safety while maintaining all the advantages of wood. Wood concrete practically does not burn and emits very little smoke when heated.
The vapor permeability of arbolite is comparable only to wood. It will always create a very comfortable microclimate indoors. Wood concrete is indispensable in the construction of saunas, baths and other premises with high level humidity.
Good resistance to tensile loads. This is very important during seasonal soil movements, when the walls of the house may begin to “move” and crack.
Frost resistance. Arbolite is able to withstand temperatures down to -50° C. Unfortunately, when alternating negative temperatures and high humidity, the shelf life of wood concrete is significantly reduced.
Light weight. When building from wood concrete, you can do without practically a foundation, since the blocks do not exert much load on the ground.

Disadvantages of wood concrete

Low strength. Only low-rise buildings or interior partitions are allowed to be built from wood concrete.
The durability of a material directly depends on the quality of its constituent materials. Unfortunately, on the market you can find wood concrete made from low-quality raw materials in violation of technology. Such blocks will not last long.
Arbolite manufactured in accordance with GOST has a cost comparable to the cost of foam concrete.
When building a house made of wood concrete, you will definitely need external finishing walls, because due to errors in the size of the blocks, the seams are not quite neat, and the material itself is not very decorative in appearance.

Arbolite manufacturing technology

The process itself is quite simple, so it is quite possible to make wood concrete yourself, for example, for the construction of small outbuildings. The only drawback is the slow hardening of the composition, which is why it started construction work you will have to wait at least three weeks.

And finally, a little more information. Wood concrete structures can be erected in any climatic conditions and on any soil. Arbolite house the weight is eight times lighter than a brick one and three times lighter than a house built from foam concrete. Area of application of wood concrete in suburban construction- construction of two-three-story buildings residential buildings, as well as fences, bathhouses, garages, utility rooms. As you can see, the range of possibilities of wood concrete is very wide. published