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

Arbolit 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 brand depend on them. Wood chips are strictly controlled before use. The most optimal types of wood for the production of wood concrete are pine, beech or spruce.

Even the time of harvesting the wood - late or early - plays an important 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 the wood concrete is cement with a grade of at least 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 for its rapid solidification, various additives are used, such as potassium chloride salts, water glass. Wood chips and cement do not mix well, so the process of making wood concrete must go without disrupting the 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:

• Heat-insulating wood concrete, with a density of about 500 kg / cu. m. As the name suggests, this material is used as an insulating layer in the construction of interior partitions, which are not loaded.
• Structural wood concrete. Its density is much higher and can reach 800 kg / cu. m. This is due to the fact that the amount of cement in it is much higher than chips. The technical characteristics of such wood concrete make it possible to use it in the construction of load-bearing supports and walls. To give it greater strength, reinforcement with mesh or rods is possible.

Arbolite is produced in two types:

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

The advantages of wood concrete

• Good thermal insulation properties. The thermal conductivity of wood concrete is only 0.08 W, which is much better than that of concrete or brick.
• Fire safety while maintaining all the advantages of wood. Arbolite practically does not burn and emits very little smoke when heated.
• The vapor permeability of carbolite is comparable only with wood. Inside the room, it will always have a very comfortable microclimate. Arbolite is indispensable for the construction of saunas, baths and other premises with high levels of humidity.
• Good resistance to tensile loads. This is very important during seasonal ground movements, when the walls of the house may begin to "walk" and crack.
• Frost resistance. Arbolite is able to withstand a drop in temperature to -50 ° C. Unfortunately, with an alternation of negative temperatures and high humidity, the shelf life of wood concrete is significantly reduced.
• Low weight. When building from wood concrete, you can practically do without a foundation, since the blocks do not exert a large load on the ground.

Disadvantages of wood concrete

• Low strength. It is allowed to erect only low-rise buildings or interior partitions from wood concrete.
• The durability of the material directly depends on the quality of the materials included in it. 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 made in accordance with GOST has a cost comparable to the cost of foam concrete.
• When building a house from wood concrete, external finishing will definitely be required. walls, because due to errors in the size of the blocks, the seams are not quite neat, and the material itself is not too decorative in appearance.

Wood concrete manufacturing technology

The process itself is quite simple, so arbolite can be made independently, for example, for the construction of small outbuildings. The only drawback is the slow hardening of the composition, which is why the start of construction work will have to wait at least three weeks.

And finally, some more information. Wood concrete structures can be erected in any climatic conditions and on any soil. An arbolite house is eight times lighter in weight than a brick house and three times lighter than a house built of foam concrete. The scope of wood concrete in suburban construction is the construction of two-three-story residential buildings, as well as fences, baths, garages, utility rooms. As you can see, the range of possibilities of wood concrete is very large. published by

Due to its composition and characteristics, arbolite has a number of advantages and disadvantages.

The pluses allow wood concrete blocks to compete with traditional building materials, while the minuses make it impossible to use in certain conditions (high-rise construction, humid environment).

Objectively, there can be no building material consisting of solid merits, otherwise it would be used everywhere, and others would be forgotten.

Considering the wood concrete, one cannot fail to mention its shortcomings, without the knowledge of which information about this material will be incomplete.

Material prepared for the site www.site

Pros of wood concrete

1. Increased flexural strength... Thanks to this property, which the versatile oriented wood chips impart to the block, the arboblock does not crack. This ability is indispensable both during transportation and during the operation of an arbolite house.


2. Sound absorption capacity(at a sound wave frequency of 125-2000 Hz, the sound absorption coefficient of wood concrete is 0.17-0.6 units, depending on the density, for example, this parameter for wood is 0.1, and for brick - 0.04) ...


3. Low thermal conductivity(0.07-0.18 W / m).


4. Incombustibility(wood concrete block does not support combustion). Despite the fact that wood chips can occupy up to 90% in the specific weight of the block, wood concrete is considered a low-combustible material. According to the categorization of GOST 12.1.044-89, wood concrete belongs to group G 1 (slightly flammable). According to GOST 30402 - to group B 1 (hardly flammable). According to GOST 12.1.044.89 - to group D 1 (low smoke generating).


5. Convenience of processing... Arbolite has successfully combined the advantages of wood and the strength of concrete. Thanks to this, the block is easy to saw, but it holds well the fasteners twisted into it.


6. Plastic... Again, due to the significant content of chips in the arboblock, it does not break, but is reversibly deformed and is able to restore its shape after removing the load acting on it.


7. Arbolite does not lend itself to decay.


8. Excellent breathability.


9. Light weight- makes the construction process comfortable, and reduces the requirements for the foundation. For comparison, the weight of wood concrete and brick (of the same volume) is correlated as 1: 3.


10. Low cost of building an arbolite house in comparison with other materials. The parameters and the price of wood concrete per cube are given in the table.

Plus, there is another important property that contributed to the revival of interest in wood concrete construction - environmental friendliness... The block contains only 10-20% of cement and chemical components, most of which are food additives.

Cons of wood concrete

1. Inappropriate use in rooms with high humidity levels... Arbolite block is able to absorb from 40 to 80% of moisture from the external environment, which reduces its properties. The drawback can be partially eliminated by additional finishing with any material that will provide reliable adhesion to the block surface (for example, plaster).
   Note. There are wood concrete blocks with facing, i.e. one surface has a decorative coating.


2. Arbolite is unstable to the influence of aggressive gases.


3. The need for additional finishing of the basement of the house and the removal of the cornice... Ensuring dryness is a guarantee of long-term functioning of the material, which is 90% wood. For the same reason, it is necessary to drain water and remove snow from the base.


4. Not perfect block geometry(the overall dimensions of the wood concrete block can vary from 0.5 to 1.5 cm). This does not affect the process and speed of erection of the wall. However, it is impractical to use special mixtures; masters advise laying wood concrete on a cement-sand mortar. In this case, the thickness of the masonry allows you to level the unevenness.

As you can see, the advantages of wood concrete outweigh its disadvantages. For greater persuasiveness, below is a table containing the comparative characteristics of common building materials.

How to choose a wood concrete block

Due to the simplicity of manufacturing the block and the availability of its components, a lot of wood concrete blocks of private production have appeared on the market. Like foam concrete, wood concrete made with violations of production technology is often found, respectively, of poor quality and unsuitable for.

How to determine a high-quality wood concrete and not buy a fake?

Masters advise paying attention to indicators such as:

• low price Is the main criterion. It is unlikely that a manufacturer will sell quality material at a price below market value. A decrease in price may be due to the use of unacceptable components. For example, wood chips can be replaced with sawdust, and environmentally friendly additives with harmful chemicals;

• delamination index (heterogeneity)... The block should not be divided into its constituent parts. According to GOST, this indicator should not exceed 10%;

• lack of certificate... Arbolite blocks are subject to certification. By the way, pay attention to the authenticity of the certificate. Although, the availability of documents is a dubious advantage, since everything is bought and sold, including certificates of quality and conformity;

• significant violations of the block geometry... They can be caused by two factors: either the presence of chips of different sizes, which is unacceptable, or low-quality equipment or a violation of production technology;

• color and foreign matter... Various shades of green and brown indicate that the block is not dry enough even at the manufacturing stage. Natural color is gray. The impurities can be soil, bark, twigs, straw, leaves, etc. Their presence in the composition at the level of 5% is permissible. However, the craftsmen consider such a block to be of poor quality and do not give a guarantee for work;

• oversized chips... Such chips are not completely impregnated with chemical compounds, which ultimately affects the strength of the block (the adhesion of chips and cement is disturbed);

• using sawdust or small chips... This is also unacceptable, since the proper reinforcing bond is not provided. A block made of fine chips is initially fragile. The manufacturer is trying to increase its strength characteristics by increasing the amount of cement in the composition. However, such an arbolite block has a higher thermal conductivity coefficient;

• the volume of voids between chips should not exceed 3%, visually the block should look "tightly knit";

• try to buy wood concrete blocks from the manufacturer or his official representative in the region with the possibility of on-site verification (test tests of selected samples from a batch).

Having familiarized yourself with the pros and cons of wood concrete, as well as recommendations for a relative choice, you can be sure of the correctness of the decision made, building a house from wood concrete blocks.

With this choice, many forget or do not even know about the existence of another material - wood concrete, the construction of houses from which in the 60s was popular throughout the USSR from Kamchatka to Kaliningrad.

What are wood concrete blocks: technical characteristics and properties

Arbolit are blocks or wall panels consisting of wood chips and concrete .

Understanding the technical characteristics of wood concrete blocks is not an easy task, since you need to know special terms for understanding. To understand this "alphabet", you need to spend more than one hour studying special literature. We will ease the situation and tell you about the characteristics of wood concrete in simple language.

Weight and density

Finished wood concrete block size 390x190x190 weighs on average 9 Kg... Let us clarify that this is the average weight of the dried structural block. This property allows you to use a lightweight foundation for building a house and noticeably affects the speed of work on laying walls.

The weight and density of the wood concrete block is slightly higher than that of a gas / foam block of the same size. Density of gas / concrete - 500 kg / m3, wood concrete - 650 kg / m3... This makes it possible to build from wood concrete blocks on a foundation designed for gas / foam concrete, without any significant changes in the project.

An arbolite cube is 3 times lighter than 1m3 of bricks.

Strength

Wood concrete strength - 30kg per square centimeter, for gas / foam concrete this indicator is two times less at the same price. One block with dimensions 390x190x190 can withstand a load of 30 tons. According to the structural qualities of wood concrete blocks in accordance with GOST, load-bearing walls up to 3 floors inclusive can be erected.

For wood concrete, in contrast to gas / foam concrete, you can use a lightweight arm belt 15 cm thick for reinforced concrete floor slabs, which is insignificant, but still reduces the cost of construction and its construction time.

Durability and frost resistance

Frost resistance- the ability of the material to withstand the full cycle of freezing and thawing without deteriorating the basic properties, since moisture, accumulating in the pores of the material and freezing, can cause the destruction of the material.

The greater the porosity of the material, the lower its frost resistance. For wood concrete, frost resistance is equal to F35= 35 complete cycles. In fact, this means that an arbolite house will not change its performance for more than 50 years. And if you plaster it from the outside, it will reduce the water absorption of the material and further increase the life of the building.

For comparison: for houses made of gas / foam concrete, frost resistance is equal to F20.

Durability- this is the property of a material to maintain its strength characteristics during alternating freezing and thawing.

The durability of wood concrete is confirmed by the fact that in Russia there are still houses made of wood concrete built in the 70s-80s, and they look solid and reliable.

Thermal insulation characteristics

The main distinguishing feature of wood concrete from other materials is its thermal conductivity.

Thermal conductivity is the ability of a material to conduct heat. The lower the coefficient of thermal conductivity, the slower the walls of the house will give off heat to the street and the warmer the house will be.

Arbolite block has thermal conductivity of 0.11 m ° C., gas / foam concrete block - 0.17 m ° С, brick and at all - 0.47 m ° С.

If you warm up a house from gas / foam concrete or brick in winter, it will be cold in the building until the walls are warmed up. Residents of wood concrete houses note the fact that the room heats up very quickly and remains warm for a long time, even when the heating is off.

A wall made of wood concrete 400 mm thick does not need insulation and passes according to the SNIP standards for the middle zone of the Urals and Siberia - only expanded polystyrene concrete blocks can boast of this quality, but this material is less environmentally friendly. In addition, the property of wood concrete to retain its thermal insulation characteristics over time eliminates the need to change the insulation and additionally. That. price construction of a house from wood concrete will be cheaper than other materials by 10% -20% due to savings on insulation with a similar foundation.

Shrinkage

Term "shrinkage" means a change in the volume and linear parameters of the material as a result of a violation of its moisture content.

The higher the shrinkage ratio, the more likely the house will lead, resulting in cracks in the walls.

Arbolite has a very low shrinkage coefficient from 0,3-0,4 % ... For comparison: foam block shrinkage - 0.6-1.2%, gas block - 1.5%.

Environmental friendliness

Sustainability is the building motto of our time. In the era of urbanism, people are increasingly making a choice in favor of ecology in order to be closer to nature and take everything of value that it can give. We choose environmentally friendly products, natural fabrics, and build houses from environmentally friendly building materials. In houses made of wood concrete blocks, thanks to their technical characteristics, a good air atmosphere is preserved.

As you can see, the described material solves all problems, therefore construction of houses from wood concrete lately has been gaining more and more popularity. These blocks are eco-friendly, breathable, heat-absorbing and durable.

A bit of history, or Everything new is well forgotten old

Arbolit is not a new material, but undeservedly forgotten in the 90s.

GOST standard 19222-84 for wood concrete approved in 1984, although already in the 60s they began to build the buildings of the polar station at the South Pole from it. At that time, more than 100 factories produced arbolite throughout the Union. Until now, in the Arkhangelsk region, apartment buildings made of wood concrete slabs built in the 70s and 80s have been preserved. According to the residents' reviews, these houses are very warm, despite the venerable age for the houses. This suggests that this building material is durable and does not lose its thermal insulation performance over time.

The progenitor of wood concrete can rightfully be considered one of the most ancient building materials - adobe... In those days, clay was used as a substitute for cement, and straw was used instead of wood filler. The idea of ​​mixing an astringent with natural fillers led to the creation of wood concrete.

In Soviet times, the forest industry was actively developing on the territory of the entire Union, leaving an uncountable amount of unused production waste. It was decided to find a useful use of waste from logging in the production of wood concrete. So arbolite came to the Union, and now it is actively used in modern construction.

Arbolite analog Durisol was patented in Switzerland more than 60 years ago and is still successfully used in Western Europe not only in low-rise construction, but also for industrial buildings and cottages in the premium segment. Europeans appreciate its naturalness.

By appearance, wood concrete is a certain size chip in a cement sheath. The composition of wood concrete blocks is 80-85% wood filling (chips) and high grade cement, not lower than PC500.

In modern production, they mainly use pine chips, although GOST also allows other wood fillers of coniferous and deciduous species. However, it is from pine or spruce chips that the highest quality wood concrete is obtained, since these rocks contain the least amount of organic components (sucrose) that must be neutralized.

Wood concrete chips are treated with special mineralizers that eliminate sucrose, preventing rotting and destruction inside the block during operation. It is important that the supplement used is also natural. Some manufacturers deviate from this rule, and the block acquires a specific smell.

GOST strictly regulates the dimensional characteristics of wood chips from which wood concrete blocks are made. Numerous studies have shown that optimal chip size should be the following: 25mm length, 3-5mm thickness... It is by this form of wood chips that one can determine even at first glance - a real arbolite in your hands or a work of a private master. In real wood concrete, besides wood chips, cement and mineralizer, there can be no other additives. If the block contains sand, cement hardener, etc., then such material cannot be considered a real wood concrete.

Features of the technology for the production of wood concrete blocks

The production technology for wood concrete blocks is not regulated by GOST, however, it should be understood that during manual production and during production at a factory using vibrocompression, blocks in quality, shape and characteristics will be very different.

At factory production a vibrating machine weighing several tons creates strong vibration for the wood concrete mass, thereby strongly compacting the chips. This gives the block the correct shape and tight adhesion of chips and cement.

Then the blocks go to the first stage of drying, into a chamber with a temperature of 70 degrees, where they stay for a day and gain only 40% of their strength. The remaining 60% of the blocks are obtained in a warm warehouse at a temperature not lower than +15 degrees. This is important, because if the technology is not followed, tight adhesion of chips and cement will not occur, and the wood concrete block may crumble after a few years.

Construction of houses from wood concrete is a worthy investment in a healthy future

What is being built from wood concrete? As mentioned earlier, in our country, wood concrete began to be used in the form of wall panels, from which mainly apartment buildings were built. In our time, suburban housing is becoming popular, so arbolite has become very much in demand in private low-rise construction, and also copes with the task excellently construction of baths, despite the average moisture resistance, since it has low hygroscopicity and dries quickly after water procedures. In addition, when heated and at high temperatures in the bath, the block gives off its woody smell, which creates a special aromatic atmosphere. A wood concrete bath is not subject to decay, unlike a wooden bath, since the chips inside the block are insulated and pre-treated with a mineralizer and, accordingly, are more resistant to fire.

Arbolit belongs to the group of low-flammable and non-fire-supporting materials.

Arbolite blocks are successfully used for the construction of poultry and livestock buildings.

The article was prepared based on the materials of the Novintech wood concrete block manufacturer, Nizhny Tagil arbolit66.ru.

Arbolite blocks- a building material gaining popularity with a wide range of useful properties. To better understand where and how it is best used, you need to learn about its properties and characteristics, advantages, and application features. In this case, it will be possible to most fully use the positive properties of wood concrete and minimize the influence of the negative ones.

Arbolit is a type of large-porous lightweight concrete, in which wood chips act as a filler. It is bonded into a monolithic structure with concrete - cement paste. The quality of the stages of the production process of wood concrete blocks is the guarantee of the least number of defects in the finished material.

In construction, wood concrete is used in the following forms:

• large-format masonry blocks;
• hollow blocks;
• mixtures for pouring enclosing structures.

The most widespread are masonry blocks, and they are often implied when talking about arbolite. The most popular standard size of wood concrete blocks: 500x300x200 mm, but now manufacturers offer to buy products of other sizes.

Despite the fact that it is not difficult to make wood concrete blocks, there are strict regulatory requirements that must be observed if the word "wood concrete" is used in the name of the product. Documentation refers to.

• GOST 19222-84 “Arbolite and products from it. General technical conditions ".
• SN 549-82 "Instructions for the design, manufacture and use of structures and products from wood concrete."

Blocks composition

Arbolite blocks are usually made from the following materials:

• wood chips;
• water;
• cement;
• chemical additives.

Wood chips

The strength of the finished product directly depends on the caliber of the chips used. To obtain wood concrete with properties that meet the standards, you need to use chips, the dimensions of which are specified in the GOST, which means that the particle size should not exceed 40x10x5 mm.

The best properties are possessed by blocks with chip sizes in the following intervals:

• in length - up to 25 mm;
• in width - from 5 to 10 mm;
• in thickness - from 3 to 5 mm.

It is important to use wood chips for the mixture with cement that do not contain foreign impurities, for example, bark, tree leaves or soil. Sawdust, wood shavings, straw, tyrsa and other similar materials are not suitable for the production of high-quality wood concrete. Despite this, it is considered acceptable, although not desirable, to have up to 10% bark and up to 5% foliage in the composition. This percentage of impurities does not significantly affect the final characteristics of wood concrete.

Often the reason for poor-quality material lies in the fact that wood concrete is made at non-core enterprises: often these are wood processing enterprises, where impurities get into it during the harvesting of chips.

When preparing chips in specialized enterprises, they usually use powerful equipment: roller crushers, which are able to create chips of the required caliber.

The type of wood from which the chips are made is not important for the final consumer, however, according to the technology of making wood concrete, it affects the dosage of mineralizers and the degree of compaction. For example, using larch chips requires twice as much mineral additives as other conifers. The most common chips are from spruce and pine, but deciduous trees are rarely used.

Chemical additives

Wood contains sugar compounds in its composition, which are an obstacle to the complete adhesion of the binder component (cement paste) with wood particles.

There are two main ways to increase adhesion between the components of wood concrete:

1. wood raw materials are dried in advance for several months;
2. the surface of the chips is subjected to mineralization in a special chemical solution.

However, the best binding of the components can be achieved by combining the above methods. At the same time, they help to solve some other important problems in the manufacture of wood concrete, such as increasing biostability, as well as reducing the moisture permeability of the finished material.

Among the chemical components used for the mineralization of wood chips are substances that meet the standards: calcium chloride (GOST 450-77), liquid glass (GOST 13078-67), lump silicate (GOST 13079-67), alumina sulfate (GOST 5155-74) , lime (GOST 9179-77).

Water

In order for the finished wood concrete to have a full set of the declared properties, an aqueous solution of mineralizers is prepared in advance, while the following proportions of the components are taken:

At the first stage of the process, chips are placed in a special mixer, where water with a mineralizer dissolved in it is evenly distributed over its surface. Gravity concrete mixers are not used for this, since it is impossible to achieve the proper degree of homogenization in them. The chips are mixed with the mineralizing solution for 20 seconds. At the second stage, cement is added to the mixture, mixing with it lasts 3 minutes.

Cement

The type of cement used is of great importance for the strength of the finished material. According to the standards for the manufacture of wood concrete, it should be at least 400, however, even immediately after leaving the plant, cement often manages to lose its brand during storage, therefore, in the production of wood concrete construction materials, it is desirable to use cement of 500 brands.

Arbolite blocks and the process of their formation

Blocks must be fully formed no later than 15 minutes after mixing the components. Mechanical means are often used in the formation. There are several types of formation:

• manual shaping without vibration;
• manual shaping with vibration;
• production on a vibrating machine;
• production on a vibrating machine with a surcharge.

Mechanization of the process makes it possible to achieve greater stability of mechanical parameters and linear dimensions, to obtain higher quality wood concrete blocks.

In handicraft production, the mixture for the blocks is often too fluid, and the blocks have to be forced to stand in the formwork until thickening occurs. In the general case, subject to the production technology, the molds are removed from the blocks without aging, and the raw blocks are left to dry on the floor of the workshop or on a special removable pallet.
Compaction of wood concrete blocks is not done at all with the aim of increasing their density: the main goal is to achieve the most uniform distribution of chips in the cement paste, so that the orientation of its particles is arbitrary, and the surface is completely covered. Even with the same composition, wood concrete blocks can have different characteristics if they have been subjected to different compaction. Vibration can lead to cement settling, therefore it is used sparingly for compaction. When the blocks are compacted, there is no deformation of the grains of chips, only the area of ​​their mutual contact and orientation in space change. Cement acts as an adhesive, and with different degrees of compaction, the thickness of the cement glue layer covering the chip particles changes. Therefore, after compaction, the block size does not change.

Precision in the manufacture of wood concrete

It is very important that the production is carried out in accordance with GOST, and the deviations in the dosage of components were no more than a few percent. With an insufficient amount of water in the mixture, not all of the cement will be moistened, and as a result of its excess, the strength of the product may be reduced, it will acquire excessive flexibility, and the time during which the drying block will initially set will increase.

The optimal proportions of mineralizing substances are selected empirically, since the standards indicate dosages for chips of a certain caliber at a moisture content of 25%. Correctly selected proportions will ensure a long service life of the finished blocks.

It is also important to choose the temperature of the water for the mineral mixture: it must be at least 15 ° C, therefore, in cold weather, the water is heated using mechanical or chemical heating (with a CaCl 2 mineralizer).

Physical properties of wood concrete

One of the most important physical properties of wood concrete is its density. According to the purpose of finished products, the material is usually divided into two types:

• heat insulating;
• constructional.

Arbolite with a density not exceeding 500 kg / m 3 is used as a heat-insulating material. Such a material can be used wherever the load is distributed to other structural elements, for example, even as thermal insulation for external walls, if the weight of the roof and floors is taken by other load-bearing parts.

Structural wood concrete usually has a density in the range from 550 to 700 kg / m 3, however, there are products with extremely high density up to 850 kg / m 3. Despite the superiority in strength, such samples are inferior to lighter ones in thermal insulation properties. The block density is measured after it is completely dry.

For the manufacture of walls, it is possible to use cast wood concrete, their final density will be about 300 kg / m 3, while the bearing capacity of such walls will correspond to stone ones with a density of 550 kg / m 3.

Block strength

The main characteristic of blocks used to classify their bearing capacity is compressive strength, which gives the product a class and brand. It is determined by the average test results performed on the entire batch of samples. The wood concrete class determines its guaranteed strength, and its presence in the party means that at least 95% of its samples correspond to it.

DENSITY, KG / M3	BRAND	CLASS
400 — 500	M 5	B 0.35
450 — 500	M 10	B 0.75
500	M 15	B 1.0
500 — 650	—	1.5
500 — 700	M 25	2.0
600 — 750	M 35	2.5
700 — 850	M 50	3.5

It is customary to establish a relationship between a brand and a class using the coefficients of variation. The gap between these characteristics can tell a lot about the specifics of the organization of production work. It is generally accepted that the smaller it is, the higher the organization of work. The acceptable gap for the first category is no more than 18%, for the highest - 15%.

It usually makes sense to assign a class to large masonry stones, which include wood concrete blocks, while this concept is not applicable to small masonry.

There are recommendations for using classes depending on the task. So, for load-bearing walls of one-story buildings (height up to three meters), materials from B 1.0 class should be used, but if the height of the walls is more than three meters - from B 1.5 class. When constructing two-story and three-story buildings, blocks of classes B 2.0 and B 2.5 are needed, respectively.

Arbolit has a number of advantages in terms of its strength in comparison with foam concrete, aerated concrete and other porous types of concrete: it is much less susceptible to cracking, since it has a high bending strength (from 0.7 to 1.0 MPa), and the value of its elastic modulus can be 2300 MPa. Moreover, its compressive strength is not less - it is typical for porous concrete.

Heat-conducting properties of wood concrete

Another very important parameter of wood concrete is its thermal conductivity. Its dependence on the density of the material is illustrated by the graph:

There is a recommended GOST thickness of enclosing structures made of wood concrete. For temperate latitudes, it is 38 cm, but in practice this value is somewhat overestimated, and very often when building residential buildings, blocks with dimensions of 500x300x200 mm are used, laying them out in one row. In the presence of external and internal finishing of such walls, a normal temperature will be maintained inside the room.

A common type of additional thermal insulation is perlite-containing warm plastering systems (thickness 1.5 - 2 cm).

When building a bathhouse and other premises in which heating occurs periodically, a special type of block laying is often used: on the edge.

Arbolite and moisture

The water absorption of wood concrete is different for heat-insulating and structural blocks: 85% and 75%, respectively. At the same time, water practically does not accumulate inside the blocks, since they are poorly wettable, and water falling on the wood concrete block flows freely through. That is why, in the construction of walls, wood concrete is not used without external, facade finishing with plaster solutions or hinged protection systems.

Arbolite blocks and cold

Building materials deteriorate when exposed to low temperatures due to the fact that the water contained in their pores expands when freezing. This means that the more water a material can absorb, the less frost resistance it has. Wood concrete is characterized by low sorption moisture, which means that it is sufficiently resistant to freezing (from F25 to F50). Even for walls that are not protected from the influence of the environment, the actual service life can reach 7 - 10 years, and if the wall is protected from direct ingress of moisture, it is possible to significantly increase the resistance of wood concrete to low temperatures.

Shrinkage of finished blocks

The main shrinkage processes end at the block manufacturing stage. After that, the size reduction is uncritical (no more than 0.4% - 0.8%), it can occur in the first months of using the block after it has been laid, as well as under the influence of a load in the form of overlaps and roofs. In this regard, one should adhere to the recommendation not to carry out finishing work within the first 4 months after the completion of the main work on the creation of structures.

Non-combustibility of wood concrete

Arbolit has high fire-resistant properties:

• low-combustible material (group G1);
• hardly flammable material (group B1);
• material that generates little smoke (group D1).

Low sound conductivity

Arbolite blocks are excellent sound insulation and surpass ordinary wood and brick in noise suppression properties, the sound absorption coefficient can serve as an absolute indicator, which varies from 0.17 to 0.6 in the range of sound frequencies of 135 - 2000 Hz.

Arbolite blocks and steam

The degree of vapor permeability of wood concrete structures is about 35%, which means that wood concrete allows air to pass through, which guarantees comfort in the house at any time of the year, as well as the absence of excessive moisture. This means that in rooms where the walls are made of wood concrete, mold and mildew will not appear.

Negative properties of wood concrete

Despite the abundance of useful qualities and properties, arbolite also has negative qualities that you need to know about in order to be able to take them into account. So, questions and doubts when choosing a building material can be caused by the following facts:

Positive properties of wood concrete

There are many advantages of wood concrete, which should not be forgotten:

1. Environmental safety of wood concrete.
   
   Arbolite does not emit toxic substances into the air, it is harmless and can be used as a structural material in the construction of residential premises.
2. Water vapor permeability.
   Due to the high vapor permeability in wood concrete buildings, a comfortable level of humidity will always be maintained, the liquid will not collect on the walls and cause the development of mold.
3. Ease.
   The remarkable elastic properties of wood concrete, as well as its lightness, make it possible to do without the construction of a heavy foundation, in addition, seismic threats are not terrible for structures made of wood concrete.
4. Ease of processing.
   Arbolite is easily amenable to all kinds of processing.
5. Ease of editing
   Like wood, you can easily make holes in an arbolite, screw in self-tapping screws, drive in nails, and mount various types of fasteners.
6. Low thermal conductivity.
   Due to the low thermal conductivity of wood concrete, in low-rise buildings, where the loads are not too high, it is possible to achieve a single-layer wall structure, since there is no additional need to install thermal insulation.
7. Good soundproofing.
   Due to the low conductivity of wood concrete for sound waves, under normal conditions in buildings, additional sound insulation of individual rooms can be dispensed with.
8. High strength.
   Due to the strength of wood concrete blocks, during the construction of small objects, it is possible not to reinforce the masonry.
9. Biostability.
   Biological destruction is not terrible for wood concrete, it is not affected by fungus, mold does not develop on it, it is not a favorable environment for the reproduction of microbes.
10. High fire resistance.
    
    Arbolite is able to withstand the influence of high temperatures for a long time, it is difficult to burn, creates little smoke and does not contribute to the spread of the flame.

Arbolit - this building material occupies the first lines in the ranking of the best building materials. Houses built from wood concrete blocks are unmatched in terms of performance. They look very solid and respectable.

Arbolite blocks - description

Arbolite is an ideal material for building a private house. Today it is experiencing a rebirth, since with the introduction of new technologies it has become even better. Arbolite blocks are used more and more actively for the construction of individual houses every year.

Arbolite blocks are produced in the form of three-dimensional square blocks, which consist of an aggregate in a binder shell. The porous structure of the finished material helps to regulate the exchange of air in the room.

Arbolite in its properties is similar to construction materials made of wood, and in addition, it has many additional advantages. It is a durable, environmentally friendly material with excellent thermal insulation properties.

Arbolite blocks are not afraid of loads. If the permissible values ​​of external influences are exceeded, cracks will not appear on it, since this material will simply be uniformly compressed.

Wood concrete is made from wood, more precisely from wood waste. Arbolite blocks are 80-90 percent of wood chips mixed with cement. Biostability to the blocks is given by cement, which protects wood waste from external biological influences.

Arbolite is a refractory, non-combustible material; it can withstand high temperatures for a long time.

Video presentation on wood concrete blocks:

Arbolit has excellent construction qualities:

• Easy to saw.
• It perfectly holds screws and nails, so any materials can be easily attached to arbolite surfaces.
• Arbolite adheres perfectly to concrete and plaster solutions.
• The shrinkage degree of wood concrete is only 0.4%, due to which the building from it is erected in the shortest possible time.

To keep the house warm, after the walls are erected, remove all "cold bridges" through which heat can escape. Previously, they were sealed with cement mortar, but now they are increasingly using polyurethane foam for these purposes.

Arbolite blocks are available in various sizes and types. Blocks can be cut and trimmed during construction.

Arbolit has multiple positive qualities. This material allows you to build low-rise buildings in a short time. It is suitable for the construction of buildings in all areas of our country, as it has unique ones.

Wood concrete composition

Arbolite belongs to the class of lightweight concrete. Blocks consist of aggregates, mineral additives that act as a binder. They also contain small amounts of chemical additives to remove residual sugar from the wood material.

Wood concrete fillers

The fillers are woodworking waste, most often coniferous or hardwood, as well as flax processing waste.

Most common forestry waste:

• sawdust with shavings and chips;

• wood chips;

• shavings;

• sawdust with shavings;

• chips.

If large wood particles are introduced into the wood concrete, the block, when moistened, will greatly increase in size and may collapse. Do not fill blocks with freshly cut wood. Some manufacturers replace the sawdust with flax fire.

The main disadvantages of wood fillers are their high chemical activity. The organic waste contains a large amount of water-soluble substances, the most harmful to arbolite sugar.

To eliminate them, wood raw materials have to be aged for more than three months in the open air.

Mineral binders of wood concrete

Portland cement M-400 or M-500, as well as higher grades, are used as mineral binders.

Chemical additives

The technological properties of construction wood concrete depend on chemical additives. Add them without fail.

Thanks to chemical additives, any filler can be used without preliminary drawing, since they neutralize sugar, thereby improving the quality of the product.

For this, aluminum sulfate, calcium chloride, slaked lime, and soluble glass are used. They react with sugars to make them harmless.

Arbolite blocks photo and short description

The initial stage is a thorough preparation of all the necessary components, then the preparation of the base follows, its casting into molds for the further receipt of blocks.

Types of wood concrete

Arbolite is divided into the following types:

• structural

• heat insulating.

Bearing structures or internal partitions of the structure are erected from the structural part. It has a high density. Heat-insulating wood concrete has a relatively low density and is used for sound, heat and noise insulation.

Including, to types of wood concrete can be attributed blocks with cladding, with the addition of dropout and building blocks.

With cladding

Most often, wood concrete with a finished facing surface is used for construction. To do this, at the production stage, the slabs are faced with cement-sand mortar with facade tiles or granite chips.

The external decorative pattern of the cladding depends on the type of tile, but such wood concrete looks very nice and solid. Concrete armor prevents moisture from penetrating into the slab.

With the addition of dropout

The quality of the blocks depends on careful preparation of the aggregate. The smaller the geometrical dimensions of the filler, the higher the quality of the wood concrete block.

Therefore, the sawdust is crushed on a special crusher, after which they are screened out and sorted from dust and earth. After screening, clean sawdust is mixed with mineral additives.

Construction

Arbolite products are sometimes made without a finishing layer or an inner finishing layer is made of cement-lime mortar, which is mixed with porous sand.

The inner layer should not be less than 1.5 cm thick. This inner layer helps protect building structures from corrosion.

While a rarity in our country, their popularity is growing unchanged. Over the years of its service, the arbolite has established itself only on the positive side. It combines all the best properties of concrete and wood.

Advantages and disadvantages

Many builders consider wood concrete to be a unique material.

TO pluses wood concrete slabs include:

• high thermal insulation properties;

• biostability;

• no wall insulation is required;

• environmental friendliness;

• speed of construction;

• low prices.

Arbolite is the only type of wall blocks with bending strength. An arbolite wall cannot be destroyed, so such houses can be built on soft soils, swampy areas, in places of seismic activity.

But every material, even the best, has its drawbacks. Arbolite also has them.

TO cons wood concrete slabs include:

• Fear of moisture, if the foundation of the house is not properly waterproofed, the blocks can begin to collapse.

• Low accuracy of the geometric dimensions of the blocks, so the walls have to be aligned.