Arbolit are building blocks based on cement and wood chips. It has good characteristics, which are significantly better than sawdust concrete. The article will focus on the areas in which wood concrete blocks are used, their advantages and disadvantages, as well as the manufacturing technology.
Concrete is a versatile building material. Its properties directly depend on the filler. It is easy to work with due to its liquid consistency. It is poured into a formwork or a special form and acquires the required dimensions and design strength. Arbolite is also made of concrete, but due to sawdust in the composition it has a number of differences from the usual compositions.
- Arbolite blocks are based on wood chips. Strict requirements are applied to its size and quantity – these two parameters affect the quality of the material and its brand. In addition, there are wood concrete production facilities that use cotton stalks, rice straw or bark..
- The cementing component is cement of a grade not lower than M300. Its brand affects the strength of the finished product and therefore its labeling..
- To improve the connection of the components of the mixture, special additives are added to it, ensuring rapid hardening, etc. In most cases, this is water glass, potassium or aluminum chloride salts..
- Initially, wood chips and cement are poorly combined; in order to milk high-quality and uniform blocks in terms of strength, it is required to correctly set up production with a clear technological process. During which a long and thorough mixing of all components plays an important role.
- The sliver selected for production must undergo strict control. Pine, spruce or beech work best. The nature of the wood is also important – late or early harvesting. The size of the chips should not exceed 10 mm in width and 25 mm in length. Observing these conditions, the material will turn out with high vapor permeability, but durable.
- To achieve the best thermal insulation performance. The mixture is made from wood chips, binder (cement with additives) and water in a ratio of 1: 1: 1.5. If a more durable block is needed for a wall with a high bearing load, then the proportions of the binder change accordingly.
Arbolite blocks video
The most important thing is high energy efficiency indicators in the construction of external walls of the house and the low cost of the material. But due to the low strength, it is admissible only for the construction of low-rise buildings.
Advantages of wood concrete
- In terms of thermal insulation qualities, it is ahead of ordinary concrete or brick. Its thermal conductivity is only 0.08 W / (m * C).
- It has the best qualities of wood, but unlike it, it is fireproof. Arbolite is a flame-resistant material that produces little smoke during a fire.
- When the house heats up and then turns off the heating system, the heat in the room will remain for a long time even at negative temperatures outside.
- In terms of its vapor-permeable characteristics, it is second only to wood. Therefore, there will always be a good microclimate inside the building, even with high humidity. That is why this material is chosen for the construction of a sauna or bath..
- Despite its low strength (it is allowed to build buildings from wood concrete blocks no higher than 3 floors), it resists tensile loads well. This is especially important in case of seasonal heaving of the soil, when the house begins to “walk”. These properties of the material will protect the structure from the appearance of cracks..
- Frost resistance, depending on the brand of the product, can be in the range of F25 – F50, But if humidity and negative temperatures alternate in winter, the shelf life of wood concrete is significantly reduced.
- This inexpensive material is easy to adjust to the desired size, it holds fixed objects quite firmly in it. It will be the best option for small outbuildings or garages..
- The low weight of the blocks allows you to save on the foundation, since the latter will not be subject to high loads.
Disadvantages of wood concrete
- Low strength puts the use of wood concrete blocks in a narrow framework. Only low-rise construction is allowed, interior partitions or as additional thermal insulation.
- The durability of a material depends on its quality. In addition to specialized large factories, today there are a lot of private small firms throughout the country that manufacture blocks and sell them at lower prices. But, unfortunately, the quality of their products often remains low due to the desire to reduce the cost of the product as much as possible and make it attractive to the buyer..
- The material made in accordance with GOST has a cost almost equal to foam concrete. This is due to the fact that in its manufacture it is impossible to do without human labor..
- Due to errors in the size of the blocks, the seams are uneven during masonry. And the material itself does not differ in its beautiful appearance, therefore, a finishing decorative facing of the facades of the house is required.
In total, 2 main types are produced:
- Structural. Differs in the highest density – 500-800 kg / m3. It has a proportionally higher content of cement in relation to wood chips. According to its characteristics, it is suitable for laying load-bearing walls and supports. For greater strength, it is allowed to be reinforced with rods or mesh.
- Heat insulating. Density within 500 kg / cubic meter. Designed for the construction of interior partitions, which are not loaded and as a heat-insulating layer.
Arbolite can have 2 forms:
- As blocks. This is a ready-to-use material of certain sizes. But due to the peculiarities of the material and its manufacture, there may be significant errors in size. Although they are regulated by GOST, in fact, more often inconsistencies exceed these parameters. This must be taken into account even at the design stage and calculation of the required amount of materials. The blocks are large, so the pace of construction is high.
- Monolithic. It is made just before use right on the construction site. After mixing immediately use completely. This method is suitable for creating a thin heat-insulating layer (when wood concrete is poured into a non-removable formwork made of foam or polystyrene foam). After pouring, you will have to stop at work while the composition is setting. It is at least 7 days.
Technical characteristics of wood concrete blocks
- Although wood is present in arbolite on an equal footing with concrete, this class of material refers specifically to building stone. Therefore, it is marked and given a strength class just like any other concrete product..
In shape, wood concrete blocks can be:
- with U-shaped recess. Convenient for door or window frames with lintels;
- wall blocks can be large, medium or narrow;
- rafts. But they necessarily have a layer of strong and dense concrete, since the characteristics of wood concrete cannot meet the necessary, in this case, requirements. The permissible length according to GOST does not exceed 480 cm.
The technological process itself is quite simple, therefore, for small buildings, for example a shed or a chicken coop, you can make wood concrete blocks with your own hands. But due to the slow hardening of the composition, production will take a very long time, especially if there are few molds for pouring. Especially provided that the wood concrete will gain the necessary strength only at temperatures of 12 degrees and above. Of course, you can add special chemical components that make it possible to work at lower temperatures, but this will lead to an increase in the cost of the material..
Stages of the technological process
- Obtaining wood chips. For this, waste from woodworking is suitable, which are abundant at any sawmill. Almost all types of wood are suitable, except for larch and poplar. We must not forget about the strict size restrictions, which are fundamental to the quality of wood concrete. Therefore, manufacturers make chips on their own using various crushers (shredder, hammer, disc or rotary knife).
- Proportions. If professionals use specialized dispensers, then when making self-production, you will have to be guided by weight or volume..
- Connecting components. First, the chip and cement are combined. It will not work to do this manually with a shovel, only long-term mixing in a concrete mixer is allowed.
- Filling the form. The finished mixture is fed through a chute into special forms made of metal or wood.
- Rammer. This is a very crucial stage that should not be overlooked. Manual labor is used here, as the mixture must first be punctured to remove air bubbles. Further compaction is carried out on a vibrating table..
Advice: due to the poor adhesion of cement to chips, tamping should last no more than 20 minutes, otherwise the concrete will begin to separate from the chips and tamp at the bottom.
- Hardening. Occurs in ventilated warehouses where there is no direct sunlight. Forms are removed in a day. Further transportation is possible in 2-3 weeks.
Each city has more than one production of wood concrete blocks. But most often they are made in artisanal conditions and sold through advertisements on local resources. If there is no large plant nearby, then it is better to contact companies that are engaged in the construction of wood concrete houses. As a rule, they always have their own production, which adheres to all technologies.
- The largest enterprise in Russia dealing with wood concrete blocks – EcoDrev Product. They supply their products to major building materials markets. On average, the cost of a structural material is 5500 – 6000 rubles / m3, and a heat-insulating material is 4500 rubles / m3..
- Lower prices from the manufacturer “Arbolit Trade” – 5300 rub / m3 with delivery. They produce not only solid but also hollow bricks.
- Vologda Arbolit Plant also offers its products in most regions. The price of a structural block is from 4100 rubles / m3.
Buying large volumes directly from the manufacturer, you can always negotiate an additional discount.
Special equipment for wood concrete blocks is not required, it is enough to prepare standard tools:
- concrete mixer;
- large metal pallet;
- form for pouring wood concrete;
- delimiter. It is needed if in one form it is planned to fill several smaller blocks or make voids;
- large vibration sieve;
- vibrating table or hammer;
- pitchfork, shovel and bucket;
- Master OK.
Arbolite blocks drawings
This is done in two ways..
- Initially, a large volume of shavings or chips of a suitable type of wood is acquired on any sawmill. As a rule, it is always given free of charge, you only need to pay for the delivery.
- If this is not possible or the material is of poor quality, then using a chipper (which can be rented) the material is prepared independently from lumber.
- Before use, the chips are kept in the open air for 2-2.5 months. During this time, the sawdust is cleared of the sucrose present in it, which negatively affects the quality of the finished blocks (fermentation may begin). During this time, the chips are shaken several times and treated with calcium oxide, turned over. This is desirable so that the air gets into the lower layer. This will prevent decay of the material..
- Limestone is mixed with water to obtain a 1.5% solution. This will require a very large container. A chip is poured into the resulting solution at the rate of 200 l / 1m3 of chips. Stirred 2 times a day for 4 days.
- Then sift through a coarse sieve to separate large debris and leave to dry.
- Approximate proportions for wood concrete blocks look like this: 25-30 kg of cement M400 / 25-30 kg of chips / 1 kg of liquid glass / 35-40 liters of water.
- An electric concrete mixer is needed for mixing. First, fill in the required volume of water, add liquid glass and begin stirring for several minutes, for high-quality mixing.
- Then the chips are poured and mixed. It should be completely wet so that there are no dry areas..
- Next comes the queue of cement. If you fill up the entire volume at once, lumps will inevitably form. Therefore, it is necessary to fall asleep gradually into a working concrete mixer..
- Without stopping the work of the concrete mixer, all the cement is added until it forms a homogeneous mass with the chips. This is only possible if the chips are all evenly wet..
- The finished wood concrete mixture is laid out in split forms or formwork. If there is a vibrating table, then the process is greatly simplified. After filling out the forms, it only remains to wait for the result and extract the finished blocks.
- When self-made wood concrete blocks by a handicraft method, manual labor is most often used during compaction. To do this, you need to prepare a rammer in the form of a sheet of metal to the size of a mold with a handle..
- The form is a box made of metal or boards without a bottom. Install it on an absolutely flat surface, pour a layer of the mixture and tamp it. The number of layers depends on the height of the mold. The more of them, the more high-quality and durable the block will turn out. On average, about 5 layers are poured. To remove excess air, the mixture is pierced after each pouring with a pitchfork or a metal rod..
- For the highest density, ramming should be done in such a way that the ramming appears as little as possible. It is best to alternate between strong and weaker pressure.
- At the end, the excess solution is cleaned off with a trowel.
- The best strength is achieved with a vibrating table. In this case, manual ramming is not necessary. After pouring the mixture into the mold, it is pressed with a load and vibration is turned on for 15-20 minutes.
- Then there is the moment of drying. If the strength of the wood concrete solution is high, it is allowed to remove the mold immediately from the raw blocks and send them to dry. But with a more liquid consistency, this cannot be done. Since the block will lose its geometry.
- The technological process involves drying the blocks for 2 days at a temperature of 60 ° C. But at home, they are dried just outside for 2-3 weeks, previously covered with a film..
Production of wood concrete blocks video
- Finished wood chips can be bought from small manufacturers of wood concrete blocks..
- For easier removal of the block from the mold, its inner part is trimmed with a smooth material, for example, linoleum.
- To gain strength, the blocks must be hydrated. For the first 10 days, they should dry under a film at a temperature of 13-15 ° C.
- If wood concrete blocks are needed only for insulating load-bearing walls, then the technological process can be slightly simplified..
- You can make finishing blocks right away. To do this, a layer of putty is applied to the raw block directly in the mold with a spatula and leveled.