The construction market is saturated with a variety of materials; The extensive assortment creates a difficult choice problem. If brick and timber are understandable and familiar to everyone, then newer and more technologically advanced varieties (for example, aerated concrete) cause mistrust. Arbolit is a new (although, in fact, well-forgotten old) product for many, whose advantages and disadvantages are lost behind rumors. Why are houses made of wood concrete good: projects and prices, features of buildings in our article.
Project of a two-story house made of wood concrete
A little history
The idea of combining the warmth of wood and the hardness of stone has visited people more than once and was realized in different ways. Since time immemorial, adobe has been known - a brick made from clay and plant additives, straw or reed. In the dry Central Asian climate, houses made of this material stand for centuries, withstanding summer heat and winter frosts.
A successful option that combines both materials was developed in Holland in the 30s of the last century. It quickly spread around the world under the Durisol brand. In the Soviet Union, they tried to produce similar blocks back in the 30-40s, but their quality was low due to technological shortcomings (low-grade cement, incorrect chip format, mismatched equipment).
High-quality domestic material was developed, standardized and certified in the 60s; it was called arbolite (from Latin arbor - tree). Modern factory-produced wood concrete blocks, produced in compliance with technology, are an effective material with a set of unique properties. The reputation of wood concrete suffers, as a rule, due to the products of folk craftsmen.
Industrial production blocks
Composition and technology
Arbolit, from which houses were built en masse already 60 years ago, belongs to the family of lightweight concrete, which has now won a significant market share from brick. This is a composite (complex in composition) material consisting of the following components:
Wood chips(crushed pine sawdust, crushed cotton stalks, flax or hemp stalks). The organic part is a filler and occupies 80-90% of the volume. Chips have a specific shape and size, which distinguishes wood concrete from sawdust concrete.
Cement. Mineral binder. To make the block durable, Portland cement grades M400-500 are used.
Additives-mineralizers. They neutralize the sugar present in wood and affect the strength of wood concrete (improving the adhesion of wood chips to cement). Calcium chloride, soluble glass, aluminum sulfate are used (the latter is food additive E-520, which is actively used in the confectionery industry and in fish canning factories).
Vibropress at work
The production of blocks is carried out on automated lines and is divided into stages:
Preparations. The wood chips are crushed, soaked and processed chemical composition. If the chips are pre-conditioned for fresh air 4-6 months, no additives needed, sugar breaks down on its own.
Moldings. The required, precisely adjusted amount of wood chips and cement are mixed and formed into blocks.
Drying. On a brick press, the blocks are compacted, obtaining their final density and geometry corresponding to GOST.
Classification
Blocks, panels and slabs are made from wood concrete (another name for wood concrete). According to the state standard, wood concrete products do not require additional insulation. Products vary in density (percentage of sawdust), they are classified according to their purpose:
Structural. Used for the construction of external walls.
Thermal insulation. For interior walls.
Based on their dimensions, blocks are divided into: wide, medium, narrow and connecting. In addition, the elements are marked from 5 to 50 (strength indicator).
Wood concrete house - fast, cheap, energy efficient
Specifications
Arbolite blocks are applicable in all climatic zones(arbolite buildings are found not only in middle lane, but also in Antarctica, at the Molodezhnaya polar station). Such multi-purpose use was made possible thanks to the combination of technical characteristics of the material:
Light weight. The density of structural blocks is 500-850 kg/m 3, heat-insulating blocks - up to 500 kg/m 3.
Low thermal conductivity. In terms of parameter (0.11 W/(m*K)) it surpasses wood. A wall with a thickness of 0.3 m corresponds to 0.6-0.7 m of brick in terms of its ability to retain heat.
Environmental friendliness and biostability Wood concrete is safe for human health; the material does not rot, fungus and mice do not grow in it.
Fire resistance. The material can withstand an open flame at a temperature of 1000°C for up to an hour and a half, then it begins to smolder.
Sound insulation and vapor permeability The block structure absorbs sounds and supports natural ventilation and humidity control, which ensures a comfortable microclimate in the house.
Comparative characteristics of popular building materials
Homemade mistakes
The technological chain for the production of wood concrete is described in one phrase: a mixture of concrete and wood chips is placed in molds and dried without additional heating (firing). External simplicity is deceptive. The absence of obvious technological problems encourages home craftsmen to self-production arbolite blocks. Having decided to save money, a garage manufacturer is guided by the following misconceptions:
Any wood chips will do (even sawdust from a sawmill).
The brand of cement has a slight effect on the strength of the product.
The mixture is concrete, so you can stir it in an ordinary household mixer and neglect the mineralizer.
You can do without a press or assemble it yourself.
The form is easy to construct from plywood or foam concrete. Since the mixture is thick, the formwork can be removed immediately, and the blocks will dry under a shed or in a barn.
Problem areas in masonry made from artisanal wood concrete
The output is a fragile product that crumbles along the edges and has incorrect proportions (not according to GOST). Handicraft production that throws thousands of cubic meters of low-quality blocks onto the market discredits industrially produced material. Until the buyer sees real, strong and smooth products, he will consider wood concrete to be a worthless material.
On our website you can get acquainted with the most popular projects of houses made of wood concrete blocks from construction companies presented at the exhibition of houses “Low-Rise Country”.
Advantages and disadvantages of technology
Thanks to the technical characteristics of the material, building a house from wood concrete blocks is becoming increasingly popular. Houses made of wood concrete blocks have a number of advantages:
Low cost. Wood concrete is cheaper than most building materials (the cost is comparable to foam concrete), which makes it possible to inexpensively build a house from wood concrete; the average price can be around 2.5 million rubles for housing for a family of 4-6 people.
Light weight. Speeds up work and allows the use of a lightweight foundation.
Strength. Good performance impact and bending strength (not prone to cracking, unlike cellular concrete).
Arbolite surface has high adhesion
Simple mechanical restoration . The blocks are easy to saw, drill and hold fasteners.
High adhesion. High-quality adhesion of the wall surface to concrete and plaster (without additional reinforcement).
Frost resistance. For facing blocks, 50 freeze-thaw cycles are guaranteed.
Shrinkage. Minimum, 0.4% (for wood up to 10%).
Building a house from wood concrete has the following nuances:
You can use adhesive for cellular concrete, which eliminates cold bridges from the walls.
The plaster is applied to a dense and uniform surface without a mesh.
There is no need to install forced ventilation.
External cladding hides a boring wood concrete façade
On our website you can find contacts of construction companies that offer the service of building houses from wood concrete blocks. You can communicate directly with representatives by visiting the “Low-Rise Country” exhibition of houses.
When designing a house made of wood concrete, you need to remember the disadvantages:
Hygroscopicity. The problem with many cellular concretes. But if foam concrete block which has absorbed moisture may crack, then the wood concrete swells, remaining intact. The disadvantage is eliminated by plastering.
Blowing. It can be removed with rough plaster.
Appearance . The facade looks unpresentable, which, however, can be easily corrected with decorative exterior decoration.
Features of using technology
Housing built from arbolite blocks combines the strength of brick and comfort wooden building; There are also some disadvantages, which are quite easy to eliminate.
Video description
What are the advantages and disadvantages of this material, as well as detailed characteristics, we analyze it in this video. Let us dispel all fears and misconceptions. What is an arbolite block, what is it made of and what is it for?
1. Design
Any project created for the construction of a house made of wood or stone is suitable for construction from wood concrete. When adapting a project, they must consider next steps works:
Geodetic research. An important parameter is the depth groundwater. High level water is the reason for raising the foundation or changing its type.
Floors. The strength of wood concrete allows it to withstand both wooden beams and reinforced concrete (prefabricated monolithic) floors.
Waterproofing. She needs to be given enough attention; it is possible to use vapor barrier materials or hydrophobic paint.
Insulation. Your estimate will cost you no money on solid thermal insulation; the material is exceptionally frost-resistant.
Finishing. Since wood concrete holds fasteners well, for finishing you can use not only plaster, but also a block house, lining, and facing bricks.
Country house made of wood concrete, lined with brick
2. Foundation
Most often, for houses made of wood concrete, which has a low specific gravity, a lightweight foundation is chosen, usually a shallow strip foundation. This allows you to reduce costs (a conventional foundation accounts for 25-30% of all construction costs). High groundwater forces us to replace the foundation (with a columnar one) or build a basement.
3. Walls
The use of large arbolite blocks facilitates and speeds up construction; The masonry scheme is no different. It is convenient to use a special adhesive for cellular concrete as a mortar for masonry. The seam will not serve as a “cold bridge”, as it will be thin (for masonry 1.8-2 m high, the seam thickness is 1-1.5 cm).
The masonry technology involves wetting the blocks with water or treating them with moisture-retaining impregnation. This prevents moisture from being excessively absorbed into the blocks and deteriorating the quality of the masonry mortar.
Construction of the first floor
4. Partitions, door and window openings
Use for internal partitions narrow blocks will save money without compromising the heat and sound insulation of the rooms. There are no problems when creating openings; blocks are easy to saw hand saw and quickly - with a chainsaw.
5. Roof
The wood concrete frame confidently withstands heavy roofing; You can put slate on the roof or decorate it with natural ceramic tiles. Experts recommend designing wide roof overhangs who can protect arbolite walls from slanting rain.
6. Insulation
Arbolite walls do not need insulation, but heat can be lost in other ways. To identify weak points, conduct a heat audit of the house. The most likely heat losses are through the following parts of the structure:
Floor. Due to its proximity to the ground, 50-60% more heat is lost through the floor than through the walls. For thermal insulation, mineral wool or expanded clay are mainly used.
Thermal imaging diagnostics - effective method checking the thermal insulation of a country house
Ceiling and roof. The ceiling is insulated if attic space non-residential Otherwise, the roof is insulated.
Window. The gaps are filled silicone sealants, seals or polyurethane foam.
Subtleties of design
A country house built from wood concrete looks like wood or stone thanks to its finishing. The choice of material is more a matter of aesthetic preference than functionality.
Video description
About choosing wood concrete in the following video:
Exterior finishing
The main method of finishing wood concrete is plastering. It is important to remember that the consumption of plaster will be 1.5-2 times more than for concrete wall. However, even without a reinforcing mesh, the finishing layer will be strong and even. For finishing it is permissible to use the following types of plaster:
Cement. The standard block will be protected by a 20 mm finishing layer.
Decorative. Latex, lime and acrylic options are used.
Limestone. Needs to additional processing(primer and putty).
So that the walls can breathe, when using cladding, a ventilation gap is arranged (most often wooden sheathing). The following is used as cladding:
Block house, lining or imitation timber. Externally, the housing will not differ from a wooden building.
Vinyl siding. Offers a huge number of options, is non-flammable, practical and easy to attach directly to the wall.
Facing brick . An ideal opportunity to turn your home into a brick house.
Wood concrete house, external finishing with half-timbered style elements
Interior decoration
Some of the most common methods interior decoration arbolite walls:
Plastering and cladding plasterboard sheets (on the frame). Both options allow you to later paint the walls or cover them with wallpaper.
Clapboard finishing. A sheathing is installed for it, playing the role of a ventilation gap and helping to hide communications.
Design styles
House designs made from arbolite blocks successfully reproduce the characteristic features of popular architectural styles, often improving the comfort of a residential building.
1. Chalet
Traditionally, chalet houses are made of two floors, with the first floor being built from stone and the second from wood to convey the spirit of a mountain hut. A feature of original chalets is often high humidity ground floor. Features of building a chalet from wood concrete:
Ground independence. Wood concrete chalets can be built on problematic soils, unlike stone chalets.
Chalet style house. Stone plinth or stone finish?
Facing. For the first floor, basement panels with stone relief are used, for the second floor - a block house or wooden lining. In both cases, installation is carried out on the lathing. A person who did not take part in construction work, is unlikely to determine with certainty what the house is built from.
Microclimate. It will be equally comfortable on both floors.
2. Minimalism
Buildings in the minimalist style are traditionally built from lightweight concrete or brick and constructed using a monolithic method. They are characterized by strict geometry and a minimum decorative elements. Design choice in interior design are subdued colors and finishes with a smooth texture (plaster or tiles predominate)
An arbolite house, the design of which embodies this style, has additional advantages:
A house made of wood concrete does not need an expensive slab or buried foundation, like a building made of monolithic reinforced concrete.
Arbolite wall covered with glass wallpaper
Arbolite walls after finishing will look the same as concrete (brick) ones, but unlike them they are able to breathe.
If the project includes French (panoramic) windows, a house made of wood concrete will have much less heat loss than its concrete or brick counterpart.
3. Loft
The loft arose when savvy city dwellers began to inhabit empty industrial buildings with spacious rooms and huge windows. What was previously considered a disadvantage - open communications and rough finishing (or better yet, its absence) suddenly became a sign of chic and belonging to the elite.
“Real” lofts in industrial buildings are not very practical, so they have become widespread country houses made of concrete or brick, which were specially designed for this brutal style. Arbolite blocks are no less durable, but thermal insulation qualities much (2-3 times) superior to traditional ones stone materials. It is worth taking a closer look at wood concrete if the loft project includes large windows and siding; heat loss will be minimal, and finishing will be easy and quick.
Heat loss large windows compensated by walls made of wood concrete
4. Traditional (ethnic) style
For the construction and decoration of houses in ethno-style, they try to use natural materials, avoiding the use of brick, tile, glass or chrome elements (forged are allowed). Such houses in Asian or folk European (the same chalet) style are environmentally friendly, but often cold and often weakly built. Arbolite houses can give a head start in terms of weight, comfort, fire safety and energy saving.
Video description
How to build a house from wood concrete? What type of foundation does a house made of wood concrete blocks require? How much does a turnkey wood concrete house cost?
5. Rustic
The style is characterized by deliberately rough, minimal processing of stone and wood. The same materials are used for interior decor, the interior is enlivened by natural fabrics, clay dishes and animal skins designed to highlight the natural beauty of nature. The advantages of wood concrete are immediately visible:
Compared with arbolite building, a house made of stone is too heavy for problematic soil, a house made of wood is powerless in the face of fire.
In climates characterized by long wet periods (long autumn and spring rains), owners of a house made of wood concrete do not have to worry about the appearance of mold and rot.
An arbolite house with a block house finish is difficult to distinguish from a wooden one
Projects and prices of wood concrete houses
Many construction companies have own production arbolite blocks, which allows them to offer houses at reasonable prices. The customer can choose a standard (ready-made) project and modify it, or order an individual project with full development. A turnkey house made of arbolite blocks is available in several configurations:
Economy. The foundation is being laid, the walls and roof are being erected. The option will cost from 11,500 rubles/m2.
Standard. In addition to the frame and roof, the customer can count on the installation of windows and doors, as well as insulation of floors. From 12500 rub./m2.
Optimal. In addition to the previous work, facade (exterior) finishing is carried out, the roof and attic are insulated. From 14,500 rub./m2.
Premium. A complete set of construction and finishing works, wiring of communications and other activities provided for in the contract. From 17,000 rub./m2.
Let's look at some projects of houses made of arbolite blocks:
Project country cottage made of arbolite turnkey
Houses made of arbolite blocks, the price of which allows you to keep the budget within reasonable limits, are also pleasing with the construction time: a house with an area of 100 m2 is completed in 2.5-3.5 months (depending on the complexity of the project). Average prices for projects in the Moscow region:
Houses with area up to 100 m 2: 1,470 - 1,860 thousand rubles.
From 100 to 200 m2: 2,350 - 3,470 thousand rubles.
More than 200 m2: 3,980 - 6,295 thousand rubles.
Conclusion
By many parameters Vacation home from wood concrete can become profitable solution for those who are thinking about their own family nest. Thanks to a huge selection of modern finishing materials(plasters, plinth panels, liquid wallpaper) a house made of wood concrete will not lose in appearance to its brick, wood and concrete counterparts. The multiple win will be its unrivaled ability to retain heat.ARBOLIT- This building material is a type of lightweight concrete. The composition of the wood concrete includes M500 cement; water; wood chips of certain sizes, treated with lime, alumina sulfate, or simply aged for at least a month outdoors(chips should be at least 80-90% of the total volume of the block). Arbolite is made without the use of sand. Arbolite is widely used in Russia for the construction of houses, dachas, bathhouses, garages, but mainly in those regions where there is a lot of forest. After all, in order to produce 1 m3 of wood concrete, you need 1.3 m3 of dry wood chips of the sizes determined by GOST. That is why all the main production of wood concrete in Russia is located in regions rich in forests.
Arbolite is a large-porous material that provides excellent air exchange in rooms, thereby making the microclimate in the house very comfortable for living;
wood concrete density is 500-600 kg/m3, which allows saving on the foundation;
wood concrete has low thermal conductivity;
the strength of wood concrete B2 and excellent characteristics of tensile and bending strength make it possible to build houses with a height of 2-3 floors with a wall thickness of 30-40 cm without any problems. In this case, you can use both wooden and reinforced concrete floors;
big and convenient sizes blocks speed up the construction process and save money on paying workers;
despite the fact that wood concrete consists almost entirely of wood chips, it does not rot and is not susceptible to infection by microorganisms and fungi. Wood acquires such properties after processing, provided it is in a solution of high-grade cement and mineral additives.
wood concrete belongs to the class of fire-resistant materials and is able to withstand an open flame with a temperature of at least 1000°C for 45-90 minutes.
Wood concrete is resistant to impact and mechanical stress, and at the same time is easy to drill and saw, and easily holds fasteners.
The specific heat capacity of wood concrete is several times greater than that of brick, which is why houses made of wood concrete are cool in the summer heat, and in the cold of winter, walls made of wood concrete can retain heat for a long time.
Arbolite is manufactured in accordance with current GOST 19222-84 and Instructions for the design, manufacture and use of structures and products made of wood concrete (Approved by resolution State Committee USSR for Construction Affairs dated May 4, 1982 No. 116).
History of wood concrete
Developed and standardized in the 60s. During the years of the USSR, more than 100 wood concrete plants were built.
Wood concrete production technology
For the manufacture of wood concrete and products made from it, it is used following materials:
* mineral binder (Portland cement, Portland cement with mineral additives, sulfate-resistant cement - except pozzolanic - according to GOST 10178 and GOST 22266 grades of at least 300 - for heat-insulating wood concrete and 400 - for structural wood concrete);
* organic fillers (chopped wood from waste from logging, sawmilling and woodworking of coniferous (spruce, pine, fir) and deciduous (birch, aspen, beech, poplar) species, hemp and flax bonfire, chopped cotton stalks and chopped rice straw);
* additional substances (hardening accelerators, steam generator, plasticizers, steel corrosion inhibitors, etc.) according to GOST 24211;
* water according to GOST 23723.
Types of wood concrete
There are the following types of wood concrete - thermal insulation (density from 400 to 500 kg/m³) and structural (density from 500 to 850 kg/m³). It is used in the form of ready-made building blocks or slabs for the construction of self-supporting walls or internal partitions of buildings, as well as as thermal insulation and soundproofing material.
Characteristics
The thermal conductivity of wood concrete is 0.07-0.17 W/(m K). The most important characteristic wood concrete, like any building material, is the compressive strength. The compressive strength of wood concrete varies from M5-M10 for thermal insulation to M25-M50 and even up to M100 for structural.
Wood concrete has increased bending strength and absorbs sound waves quite well.
Wood concrete does not support combustion and is convenient for processing. Structural types have a high flexural strength and can restore their shape after temporarily exceeding the maximum load.
The disadvantages of wood concrete include reduced moisture resistance. The outer surface of wood concrete structures in contact with atmospheric moisture must have a protective finishing layer. It is advisable to maintain air humidity in rooms with wood concrete walls no higher than 75%.
Application of wood concrete
Arbolite is used for monolithic construction low-rise buildings for residential, commercial and industrial purposes, as well as in the form of blocks.
Questions and answers
How many blocks are needed for a bathhouse measuring 2x4 meters?
Approximate calculation for a 2x4 meter bath (according to external dimensions)
Perimeter of the building (2+4)x2= 12 meters, wall thickness 20 cm (block laid on edge)
With a wall height of 2.4 m from the base, 12x0.2x2.4 = 5.76 cubic meters. minus windows and doors.
With a wall height of 2.1 m from the base, 12x0.2x2.1 = 5.04 cubic meters. minus windows and doors.
What kind of solution is used to lay arbolite blocks?
The laying of arbolite blocks is carried out using a cement-sand mixture (CSM). For greater plasticity, a certain amount of fluff lime can be added to the mixture. In order to avoid cold bridges, perlite can be added to the CPS during laying. In the same way, sawdust can be used instead of perlite, but it will require mineralization to neutralize sugars.
Is it possible to use wood concrete blocks as a foundation, or for the construction of a basement?
The use of wood concrete in the foundation is not recommended not because it will not withstand the loads, but because the natural humidity of the earth is much higher than the natural humidity of the air, even during rain, secondly, this humidity is constant, and if water inflow in the form of high water or groundwater, then everything is further aggravated. Arbolite is a material with high water absorption, i.e. it will begin to absorb water from the soil, constantly, and accordingly the material will have increased humidity. But when the humidity begins to differ greatly from the norm, the wood concrete’s thermal conductivity immediately increases and some other characteristics in the wall deteriorate. That is why it is not recommended for foundation. It is impossible to achieve such critical humidity values in a wall, even if you water it with a brassboil during the day; it will dry out overnight and release excess water into the atmosphere.
How tall can you build houses from wood concrete?
Arbolite is divided into structural and thermal insulation. As the name implies, buildings with load-bearing walls made of wood concrete are built using structural wood concrete. The strength of M25 wood concrete blocks is sufficient for the construction of a building of 2.5 floors with floors made of hollow core slabs.
When building a house made of wood concrete, is it possible to use hollow core slabs as floors?
Can be used different kinds interfloor ceilings, such as hollow-core slabs, interfloor floors made of expanded clay concrete, floors on wooden beams, etc. To evenly distribute the load on the walls, it is recommended to make an armored belt between floors.
Is it possible to use a regular concrete mixer instead of a mixing station?
No, concrete mixers are not capable of producing high-quality wood concrete mixture. An example of what happens to a concrete mixer when mixing wood concrete can be seen in our production. At the same time, the mixing station not only mixes the mixture, but also additionally, by grinding the chips with an auger, brings it to the size required by GOST.
Wood concrete is more expensive than foam concrete, why is it better?
Besides the best thermal insulation properties(on average by 70%), allowing you to refuse additional work In terms of insulation, arbolite blocks, when the load is exceeded, under shock loads, do not crack like foam concrete, but shrink, easily restoring their original shape after removing the load. This plasticity not only saves money during transportation and construction, but also protects the house from cracks during operation caused by shrinkage, temperature changes and other factors. In terms of earthquake resistance, houses made of wood concrete have almost no competitors. When building a house from wood concrete, unlike foam concrete, no reinforcement is required, which also significantly reduces the cost of work and materials. By summing up all construction costs, a house made of wood concrete is cheaper than a house made of foam concrete. Arbolite has better frost resistance (the ability to saturated with water able to withstand repeated freezing and thawing without signs of destruction or loss of strength), more environmentally friendly, etc.
Is it possible to make wood concrete not from wood chips, but from sawdust?
It is possible, wood concrete made from sawdust is often called sawdust concrete. The characteristics of sawdust concrete are superior to others in many ways similar materials, although they are inferior to wood chip concrete.
One of the promising areas is the use of wood concrete in combined load-bearing structures of roofing and floor slabs, since in existing projects an even larger share is occupied by wooden structures (coverings and floors, roofing, vestibule, staircases), which are short-lived and not fire-resistant. In our country and abroad, there is experience in residential and industrial construction using wood concrete in combined coatings as load-bearing slabs.
The production association Dneproenergostroyindustry organized the production of load-bearing structures made of wood concrete in the form of volumetric block elements for the construction of residential buildings. The Oktyabrsky DSK of the USSR Ministry of Forestry produced three-layer arbolite slabs for covering and flooring, the top and bottom layers of which were made of heavy reinforced concrete.
Slabs measuring 360x120x18 cm were used for the construction of a three-story 8-apartment building for roofing and roofing according to an experimental project of Giprolesprom (Oktyabrsky village, Arkhangelsk region).
Arbolite structures in coatings and ceilings have small spans. Flexible load-bearing elements with a span of more than 4.8 m are not produced on a mass scale. This is due to insufficient knowledge of the use of wood concrete in bending elements and limited experience in their use. Due to the low strength properties of wood concrete, its use in bending load-bearing elements of coatings and floors can be carried out mainly in the form of combined structures of a composite section in combination with heavy concrete M100-300.
Abroad, durisol slabs reinforced with steel in the tensile zone are successfully used for covering industrial buildings and residential buildings with a combined roof. Depending on the span and load, the slabs are made 10 and 12 cm thick, 350 cm long, reinforcement is carried out using reinforcement bars concreted with heavy concrete.
NIIZHB, together with Soyuznauchplitprom, has developed arbolite floor slabs for residential and public buildings of the 115th series. The panel design is designed for spans of 3.6 and 4.8 m with a thickness of 18 cm. The panel has a layered section: the bottom layer is 3.5 cm thick, the top layer is 2.5 cm thick from M200 heavy concrete, the middle layer is 14.5 cm thick from wood concrete. M25 or M35. Working fittings, made of steel class A-II or A-III, are laid in the form welded mesh(from rods with a diameter of 10-12 mm). In the bottom layer of the panel, the middle layer of wood concrete M25 and M35 with an average density of 700-800 kg/m 3 performs heat-insulating and sound-proofing functions. The weight of 1 m2 of such wood concrete panel is 253 kg. Economic effect the use of wood concrete floor panels is as follows: the cost of floor material compared to the cost of industrial wood is reduced by half; labor intensity of work on construction site decreases by 30-40%, the durability and fire resistance of floor structures increases.
Based on the results of the research, a “Guide for the design and manufacture of wood concrete products” was developed, which provides a method for calculating wood concrete elements and provides the standard and design characteristics of wood concrete. However, their scope of application is limited. They cannot meet the needs of industrial and agricultural construction, where the most effective is the use of 6 m long covering slabs. The production and use of slabs for a span of 6 m would allow for complete unification of load-bearing and enclosing structures.
The design group of the Perm Regional Potrebsoyuz developed working drawings “Large-panel arbolite slabs for covering KAP” measuring 1.5x6.0 m. Constructive decisions large-sized arbolite covering slabs with a span of 6 m were developed by engineer. Baidin with the participation of TsNIIEPselstroy.
Experience in experimental construction of buildings in which wood concrete is used in coatings and ceilings as load-bearing elements with a span of 4 and 6 m, available in the Perm region. For example, in the villages of Verkhnie Gorodki a garage was built and two-storey house, in the village of Komarikhinskaya there is a bookstore. When examining the garage and other buildings after two years of operation, it was found that wood concrete slabs with a span of 4 and 6 m in a combined covering do not have excess deformations. Compared to reinforced concrete, such coatings have a number of advantages, in particular, they do not require thermal insulation.
As the Perm experience has shown, when insulating roofs with mineral wool slabs 10 cm thick for every 100 m 2, according to the standards, 23 man-days are required for laying insulation and 7.35 man-days for installing a vapor barrier, screed and bitumen primer. Total labor costs are 42.13 man-days. When using wood concrete roofing slabs that do not require insulation, labor costs for roof installation are reduced by more than 3.4 times. In roofless combined roofs made of arbolite slabs, immediately after laying them, sealing and leveling the surfaces of the seams, you can glue a waterproofing carpet or sew slate directly to the slabs. The introduction of arbolite load-bearing coatings into construction will reduce the weight of buildings, reduce material consumption, labor intensity of construction, and the cost of constructing objects.
We talk about the installation of monolithic floors in a house made of wood concrete.
Monolithic ceiling- This Basic structure, which divides the building into floors. In fact, it is a floor, so it must meet the requirements for strength and rigidity, and withstand its own weight and the weight of everything that is on it. The ceiling must also have the necessary heat and sound insulating properties and be fire resistant. The construction of a monolithic floor can be divided into stages:
1. Installation of formwork
The formwork consists of a deck and telescopic racks, securely fixed with tripods. The racks are installed at the same distance from each other, which is determined by the thickness of the slab: the thicker it is, the closer the racks are. We lay longitudinal beams on the telescopic racks, then transverse beams perpendicular to them. We check the formwork structure for evenness using a level and a level. The quality of the surface of the future monolithic floor depends on this. Then we make the flooring with laminated plywood sheets 18 mm thick. It performs the function of a deck, which is one of the main structural elements formwork panel. The advantages of using laminated plywood include high moisture resistance - the sheets can withstand repeated pouring cycles without deformation, thanks to the laminated surface plywood sheet monolithic floors are smooth and even. We seal the joints between the plywood with film to prevent concrete from leaking into them during pouring.
2. Floor reinforcement
The reinforcement gives the structure rigidity, preventing the monolithic slab from breaking or bending. We install the reinforcement at a distance of 25-30 mm from the end to eliminate interaction between metal and air and prevent corrosion. Special plastic stops and clamps lift the reinforcement and create a protective layer of concrete underneath it. The size of this layer depends on the thickness of the floor, span length and other factors.
3. Pouring concrete mixture
After reinforcement, we perform grouting using a concrete pump. To compact the concrete mixture, we must use an internal vibrator.
In the first days, concrete must be protected from precipitation and loss of moisture, so when it rains, we cover it with a special film, in cold weather we warm it up and use antifreeze additives, and in hot weather, we moisten it to prevent cracks.
4. Dismantling of formwork
Dismantling of formwork, final stage on installation monolithic slab, occurs 4 weeks after concreting.
What types of floors are used in wood concrete construction? How are they supported on a wall made of wood concrete blocks?
In houses made of arbolite blocks with low number of storeys, the use of various options interfloor ceilings. This:
- floors on wooden, reinforced concrete or steel beams;
- monolithic reinforced concrete floor;
- prefabricated reinforced concrete floor slabs;
- prefabricated monolithic floors.
How to support floors on wood concrete blocks?
The floor structures are based on a distribution belt, which serves to evenly distribute the load on the wall and prevent local chipping of the wall wood concrete blocks. It is recommended to make the armored belt from monolithic reinforced concrete.
If it is not necessary to reduce the influence of base deformation, then for arranging the distribution belt it is allowed to use brick belts- that is, three rows solid brick, reinforced with masonry mesh.
In domestic load-bearing walls, the armored belt should be installed across the entire width of the wall.
Floor ends with outside buildings should be thermally insulated with a 10-15 centimeter layer of wood concrete. In this case, it is necessary to leave a gap of -1-2 cm between the end of the slab and the block and fill it with polyurethane foam or mineral wool (or any other easily deformable insulation).
Wooden beams on wood concrete
Using wooden structures, the ends of the beams turn around roll waterproofing. TO monolithic armored belt beams are secured using studs or anchor bolts mounted before concreting, or with galvanized metal corners.
Wooden beams rest on wood concrete blocks with a depth of at least 15 cm.
Installation of prefabricated reinforced concrete slabs
When using prefabricated reinforced concrete slabs, it is necessary to anchor the external walls to the floors. Bent reinforcing bars Ø8A240 are used - one side of the bar is laid lengthwise arbolite block, the other is attached to the mounting loop of the floor slab. Along the surface of the ceiling, the reinforcement is additionally protected with a layer of DSP. In addition, it is recommended to anchor the slabs together with metal brackets (reinforcing steel Ø8A240).
Monolithic reinforced concrete belt
The distribution belt must be made in one of the following ways:
- in formwork made of special wood concrete;
- with external formwork made of wood concrete 10-15 cm thick;
- belt across the entire width of the wall removable formwork(in this case, insulation of the armored belt is required to eliminate cold bridges).
