The construction of residential houses from arbolite blocks is a modern approach to low-rise construction and is becoming increasingly popular. The material compares favorably with brick and concrete and bypasses them in many operational indicators.
What it is?
Arbolit is a type of lightweight concrete and began to be used in construction about 60 years ago. In the Soviet Union there were more than 100 enterprises specializing in the production of this high-quality and durable building material. Then the demand for arbolite somewhat decreased, and until recently, it was not so often used in construction.
Given the latest trends and increased demand for high-quality, warm and fast-built housing, arbolite blocks were again remembered, and today the material is rightfully considered one of the main types of building materials used in low-rise construction .
In order to understand why the material has so many fans, it is worth looking at its composition, which shows that almost 90% of the total volume is wood chips. For the manufacture of blocks, only selected and clean raw materials are taken: without knots, leaves and other garbage associated with woodworking . The remaining 10% comes from high quality cement, chemical additives and bonding agents.
Externally, arbolite is represented by square volume blocks equipped with a special shell consisting of a binder. The structure of the material is quite porous, which contributes to normal air exchange in the room and maintains an optimal level of humidity. In its operational characteristics, arbolite is as close as possible to commercial wood and in many respects surpasses brick and reinforced concrete.
The scope of blocks of wood concrete is quite extensive.
The material is actively used in the construction of residential buildings and industrial structures. In buildings with a height of not more than 7 meters, internal and external self-supporting structures are erected from it, and also used for the construction of curtain walls.
According to existing standards, arbolite blocks can be safely used for the construction of buildings no higher than two floors. The material is used for the manufacture of wall panels and roof ceilings, as well as noise and heat insulation structures in the construction of private houses and summer cottages.
As can be seen from the description, arbolite can be confidently called a universal building material , which, along with its high strength and wide consumer accessibility, makes it a truly folk material.
How is it made?
Arbolitic blocks have very high operational characteristics, which is due to carefully selected raw materials for their manufacture. For example, wood chips, which is the main component of the blocks, have clearly recommended sizes, which should not exceed 40x10x10 mm .
In general, the choice of filler is determined by the region of manufacture of the material. In the northern regions, for example, as well as in the middle lane, where there is no problem in the lack of woodworking waste, mainly spruce, pine and fir shavings are used, as well as poplar, beech, birch and aspen chips. In the southern regions, hemp fire, rice straw and a cotton stalk are used as the main raw materials.
As for additives and fillers, to reduce the thermal conductivity of the material, components that increase its porosity are added to the composition, and bactericides and insecticides are used to protect the chips from rotting.
Of the chemicals present in the composition of arbolite, calcium chloride, sulfate alumina and limestone should be noted. Due to the presence of these components in the composition of the raw materials, a noticeable decrease in the water permeability and thermal conductivity of the material was achieved. Cement for the production of wood concrete is also taken quite high quality.
For example, brand 500 is used for the production of structural blocks, less often 400, while for the heat-insulating wood concrete, the cheaper version of the M300 is often used.
A prerequisite for the manufacture of blocks, determining their technical characteristics in the future, is quick molding. The procedure is performed within the first 15 minutes after the batch and is carried out on special machines or manually . The formation of mass into blocks occurs using vibration technology, which ensures high density and durability of the future product.
Tamping of raw materials into molds is carried out in several stages with the alternate formation of three layers. The optimum temperature for drying the finished blocks is 30-40 degrees . Under such conditions, the material will be ready in a day. If the air temperature does not exceed 20 degrees, then it will take 3 to 5 days to completely solidify the composition.
When lowering external temperatures below the 5 degree mark, the hardening of the concrete mixture ceases.
The manufacture of arbolite blocks at specialized enterprises is strictly regulated, and the composition is determined by the relevant GOST. With the factory manufacturing method, the deviation in the proportions is considered minimal and is usually not more than 2-5%.
Another important indicator that subsequently affects the operational properties of the material is the humidity and temperature of the working solution. Humidity is considered optimal, not exceeding 25% , as well as temperature, which should not be lower than 15 degrees.
Only strict adherence to the formulation of the solution, as well as a strict adherence to the manufacturing technology of arbolite blocks, can guarantee the high working qualities of the material and its ability to last for many years.
The main technical indicator of arbolite is its thermal conductivity, as well as strength, frost resistance and sound insulation.
- The thermal conductivity of arbolite is quite low and amounts to about 0.07-0.18 W / (m * C). This allows the external wall of the building erected from blocks to retain heat in the same amount as brickwork one meter thick is capable of doing.
- The strength of the arbolite block is also quite high and varies depending on the composition within 21-45 kgf / cm². Foam and aerated concrete, also quite often used in low-rise construction, have approximately the same strength indicator. For example, grade M25, corresponding to classes B1.5 and B2, has a compressive strength of 21-27 kgf / cm², while for M50 it reaches 45 kgf / cm². Thanks to this, the blocks do not crack and well tolerate transportation and storage.
- Arbolit is characterized by high frost resistance and is able to withstand from 25 to 50 cycles of freezing and thawing without losing its operational properties. This allows houses built from wood concrete blocks to stand in a cold climate for 50 years or more. In warmer areas, the service life of the material is increased by about half and is about 75 years.
- Sound insulation coefficient is also an important working indicator of the material and determines its use as a soundproofing shield. Sound insulation of blocks is in the range from 0.17 to 0.6 units, which is about 4 times more than the similar indicators of bricks. To ensure noise absorption, a material with a density of at least 500 kg / m³ is used, while arbolite with an index of 550 to 850 kg / m³ is used for the construction of walls.
- An equally important technical characteristic of a material is its weight . According to this criterion, arbolite also surpasses a number of other building materials, which makes it more popular. For example, the weight of one cubic meter of masonry from arbolite blocks is approximately three times less than the same volume of silicate brick and one and a half times the same volume of expanded clay concrete.
- Flammability is also an important performance characteristic. Despite the high content of wood chips in the material, arbolite does not burn itself and practically does not support combustion. According to the regulations of GOST 12.1.0044-89, arbolite belongs to the group of low-combustible (G1), low-flammable (B1) and low-smoke (D1) materials.
Arbolite blocks for the construction of external walls are usually available in the dimensions 300x250x500 and 500x300x200 mm, and blocks for the construction of internal partitions are made in the dimensions 200x250x500 mm.
The high demand for the arbolite block is due to a number of undeniable advantages of this building material.
- The complete environmental safety of arbolite is due to the absence of harmful impurities and toxic additives in its composition. The material mainly consists of natural components, and the chemicals present in a small amount are completely harmless to humans and do not emit toxic substances into the environment.
- The incombustibility of the material is due to the corresponding additives, which several times increases the fire safety of housing constructed from wood concrete.
- The light weight of wood concrete greatly facilitates the design and reduces the load on the foundation. In addition, the universal dimensions of the blocks make them very convenient for construction and transportation.
- Low thermal conductivity and high heat-saving properties of the material can save on insulating materials and help maintain a favorable microclimate in the room. In addition, arbolite is well ventilated, due to which the walls of the building get the opportunity to breathe.
- The material is an excellent sound insulator and reliably protects the room from the penetration of extraneous noise from the street or adjacent spaces.
- The ability to drive a nail into the arbolite wall or screw in a self-tapping screw also distinguishes the material from other building analogues.
- Due to the porous structure and high elasticity, the arbolite blocks are easily cut and divided into parts. The material does not crack, crumble or crumble.
- Arbolite is not interesting for rodents and insects, and is also not a favorable environment for the appearance of fungus and the formation of mold.
- The surface of the blocks has high adhesive properties and does not need additional measures to improve the adhesion between the decorative coating and the wall material.
- Buildings made of wood concrete quickly shrink, while the maximum shrinkage is only 0.4%. This quality allows you to finish the interior almost immediately after the construction of the walls.
However, along with obvious advantages, arbolite still has drawbacks. Firstly, it is a high probability of fake blocks. Unscrupulous manufacturers use construction waste, low-quality sawdust and even broken glass as the main filler. This leads to the release of disgusting quality material, which subsequently translates into big problems during the operation of the structure.
Secondly, arbolite has low moisture protection. This, in turn, necessitates the obligatory facing of walls and the application of protective finishes on them.
The disadvantages include flaws in the geometry. In comparison with a brick or a foam block, the deviation from the standard sizes is quite large and can reach one and a half centimeters. This causes certain difficulties during construction and requires the mason to carefully select the material and high skill.
You should pay attention to the rather high price of arbolitic blocks, which far exceeds the cost of foam block and aerated concrete.
The disadvantages include the inability to use the material for the construction of high-rise buildings , as well as the general instability of the material to aggressive gases.
When building an arbolite house in regions with a large amount of rainfall, it is necessary to equip the drainage system, and in the winter months to clear the basement from snow. In this regard, the use of arbolite blocks for the construction of basement walls, cornices and socles is not recommended.
Classification of arbolite blocks occurs on several grounds, the fundamental of which is the functional purpose of the material.
According to this criterion , two types of blocks are distinguished: structural and heat-insulating . The names of the categories speak for themselves. For example, the former are characterized by a higher density, which can reach 850 kg per cubic meter, and are intended for the construction of the external walls of low-rise buildings. The compressive strength of such products belongs to the high classes of B1.5, B2, B2.5 and B3.5, which corresponds to the brands M25, M35 and M50, which include structures, the design of which ST SEV 1406-78 is not taken into account.
Thermal insulation blocks have an average density of 500 kg / m³ and are used as an additional layer for the arrangement of heat and sound insulation of buildings. The compressive strength indices of such samples correspond to classes B0.35, B1 and B0.75, which indicates belonging to the M5, M10 and M15 grades without taking into account ST SEV 1406-78.
The second criterion for the classification of blocks of arbolite is the presence of additional fillers and a protective and decorative layer.
On this basis, three types of material are distinguished.
- Cladding blocks are widely used for building exterior walls. At the manufacturing stage, the front side of the workpieces is covered with cement-sand mortar, trimmed with facade tiles or form a coating of granite chips. Outwardly, this arbolite looks quite solid and beautiful, and the cement layer does not allow moisture to penetrate inside.
- Blocks made from screenings compare favorably with traditional models made using wood chips. In such models, sawdust is subjected to thorough grinding on a special crusher, after which they are sorted from the remains of solid mechanical impurities and sifting. Such products are characterized by higher performance characteristics and are in high demand.
- Building models also have a protective layer on one side at least one and a half centimeters thick. As a cladding, a cement-lime mortar is used, which is mixed with high porosity sand during application. Such blocks are used as protective structures that help protect the metal elements of the building from corrosion processes.
And the last criterion by which the division of blocks into types occurs is the geometric shape of the products. On this basis, traditional and tongue-and-groove models are distinguished. And if everything is very clear with the former, then the latter are a rather interesting design decision.
Such blocks are equipped with a “groove-comb” mount, which allows you to quickly build interior partitions from them, assembling them according to the principle of a children's designer. The sizes of such models slightly differ from the dimensions of traditional rectangular blocks and are 100x200x500 mm.
How to choose?
The main criterion for choosing an arbolite block is the search for a trusted manufacturer. The best option would be to purchase material from well-known companies that have been present on the building materials market for many years and value their reputation. This is due to the emergence of a large number of private enterprises, most of which violate manufacturing technology and produce products that do not comply with GOST.
According to experts, half of all products entering the market for one indicator or another do not meet the established requirements. Therefore, the purchase of quality material will be the key to successful construction and will not bring problems with the operation of the building in the future.
The main thing that you need to pay attention to when choosing arbolite blocks is their price.
If the material is suspiciously cheap, it means that its composition included inexpensive and possibly harmful components, therefore it is not worth buying such a product.
Very often, unscrupulous manufacturers replace wood chips of noble wood species with low-grade sawdust, as a result of which the cost of the material decreases markedly, while the quality leaves much to be desired.
The second thing that should alert the buyer is the heterogeneity of the block. It should not consist of several visible layers , since subsequently this can lead to delamination of the material.
You also need to pay attention to the violation of the geometric shape of the products. This usually happens when manufacturing products with low quality equipment, as well as when using different sized chips.
Particular attention should be paid to the color of the blocks. A quality and fully dried product is always gray. If the material has green or brown shades, then this means that it was not well dried at the manufacturing stage. In addition, straw, branches and leaves should not stick out of the block. It is also better to refuse to buy such material.
It is necessary to look at the volumes of voids - they should not exceed 3% . The block should look well-knit and not loose.
And the last thing you also need to pay special attention to is the length of the chips. As a rule, it is clearly visible in the structure of the material, and determining its average size will not be difficult.
For example, if there are many small elements in the block, this means that the reinforcing qualities of the chips are significantly reduced, and the strength of such a material will be quite low. In order to somehow rectify the situation, many manufacturers significantly increase the proportion of cement, which is why the thermal conductivity of such a unit increases markedly.
How to determine the number of pieces in 1 cube and pallet?
Before you know the number of blocks in a cubic meter and a pallet, you need to explain why such information may be needed and what it may affect. Firstly, such knowledge is necessary to calculate the optimal cost. Manufacturers differently indicate the cost of their products: someone names the price of one unit, and someone - the whole cube or pallet.
Therefore, in order to navigate prices it was easier, you need to know the exact number of blocks of different sizes in one cubic meter. For example, one cube of products with standard dimensions of 500 × 300 × 200 mm will contain 33.3 pieces, while the volume of each of them is 0.5x0.3x0.2 = 0.03 m³.
With a block size of 300x250x500 mm used for the construction of external walls, one cube will consist of 27 pieces, while in a cubic meter of material used for the construction of internal partitions with dimensions of 200x250x500 mm, there will be 40 pieces .
Secondly, it is necessary to know the exact number of blocks in a cubic meter and a pallet to calculate the amount of material required for construction. As for the number of blocks in the pallet, with standard sizes of 500 × 300 × 200 mm, 48 pieces are placed in it.
Judging by the comments of the owners, arbolitovye blocks are quite convenient to use and practical to operate. According to experts, the main working quality of wood concrete is that while maintaining almost all the operational properties of wood, it is practically non-combustible, and building from it is much simpler than cutting a house out of wood.
Compared to bricks, arbolite structures are much easier and do not require the construction of thick meter walls. Compared to reinforced concrete, arbolite also wins: audibility in houses made of reinforced concrete panels is several times higher than in houses built from arbolite blocks.
In addition, many owners note the ability of the arbolite to independently maintain the necessary level of comfort in the room: in summer in such houses it is not hot, and in winter it is not cold.
Of the minuses, the high cost of the material and the impossibility of its use in the marine and subtropical climate are noted.
You will learn about the pros and cons of arbolite blocks in the next video.