Independent production of wood-concrete blocks. Materials and proportions.

Choosing the material for the construction of homes, many users of our portal opt for wood-concrete blocks.

In order to understand what it is guided by the considerations in this case the developers, you can see Video about the characteristics and advantages of arbolitaAnd we move on to a description of the production technology.

Design features of wood-concrete blocks are governed by two main standards: GOST 19222-84 "Arbolit and articles thereof "and SN 549-82" Instruction on designing, manufacturing and application of structures and products of arbolita ". They should read every one who is going to start producing arbolita. We start this article by considering the feasibility of the production of wood-concrete blocks of its own.

The question is moot, but judging by the lively interest shown in relating to the production of wood-concrete blocksSo many people engaged in independent production arbolita, being able to achieve some success in this business.

Of course, having decided to organize a major production with a decent amount (we are talking about the production of material for sale), you must correctly assess their financial capabilities. The fact that arbolita production in pure form is characterized by a relatively low profitability. Therefore, engaging in the manufacture of this material, it is necessary to look for ways to increase profits.

a991ru (FORUMHOUSE User)

The rate of return on Arbol lower than in any other blocks, so pure production arbolita not a profitable option. If you have a little money (less than 3 million. at all), I would do wood-concrete business is not regarded as a business.

But it is quite another thing - blocks production for their own needs.

cc555h (User FORUMHOUSE):

Statement on the house (110 m³) accurately decide to do yourself, the more so because of the cost (even with the purchase of equipment) is still in the black.

Or launch an adjacent production. provides several options for this case: the provision of construction services using our own wood-concrete blocks manufacturing (because the buyer arbolita - potential customer of construction services) or a combination of blocks production Woodworking.

Chomba (User FORUMHOUSE):

Production arbolita be combined with any woodworking industry, which would complement one another. Chips - his own. Rent, electricity, water - too. 2 production accounting is also one. We give work all year round, so people are willing to work for less money with the cube, but in total, in a calendar year, they get more.

Indeed, the demand for wood-concrete blocks - a seasonal phenomenon, but to ensure stable production of profit should work all year round, and this will need working capital. As practice shows, well-organized production, even with a relatively small area (200 m²), it has a right to exist.

Production technology

Adherence to the process in the manufacture of wood-concrete blocks involves the use of suitable materials, for and determining compliance optimum ratio of additives to the use of the appropriate (depending on the manufacturing methods) equipment.

The structure of wood-concrete blocks includes the following components:

• Excelsior
• Cement (currently used and above M500)
• mineral supplements
• Water

Consider in more detail the characteristics of each component.

wood-concrete chips

Wood chips (filler) and cement - that two main components that are used in the manufacture of wood-concrete blocks. All else - is industrial water and additives which can improve the characteristics of the blocks. As the filler (instead of wood chips) can use waste production linseed (flax fire) or fire hemp. But the acquisition of such material can be difficult, so in this article we will consider the option only with wood chips.

For manufacturing blocks suitable value softwood (spruce, pine, fir, larch or), as well as some hardwood (birch, aspen, poplar or beech).

Wood-concrete chips is considered to be shredded waste wood production, with maximum dimensions - 40h10h5mm and needle-like shape. These parameters are registered in industrial technology. In practice, the owner of a small shop it is very difficult to ensure the manufacture wood-concrete chips, has the ideal size. However, this is not an unsolvable problem.

samogon124 (FORUMHOUSE User):

Hello. I traveled here for one very strong production arbolita and understand such a moment: even if the chips are not needle-shaped, namely plate (not square), it is also a good working version. So much for the needles do not need to chase.

used is wood chips, sawdust and not a part of wood-concrete blocks. Sawdust produced other material - opilkobeton.

Receive the chips a desired configuration by using crushers for crushing waste wood. For crusher, the construction of which provides for adjustment of the size of the chip, obtained at the output (chip geometry is regulated by the distance between the holes in the blades and the mill sieve size). Generally, the required size of the chip can only be achieved empirically. For example, if the wood has a high moisture content (50%... 80%), it is possible to use a sieve with mesh size - 20 mm. For stale timber having humidity - 20-25%, suitable sieve of 15 mm mesh (as, in any case, the user enters Chomba).

Disk hammer crusher can be made independentlyAnd you can buy a ready-made device.

Rambuin (User FORUMHOUSE):

After all "dancing with a tambourine" around the shaker I decided to buy a disk-hammer mill. Here's what happens at the output: managed to chip about 30 mm long. I think - at the time.

Based on comments of users exposed to the pictures, chips 2-3 cm long is quite suitable size for the production of blocks. But at the same time, debugging production technology, it is necessary to control the strength of it made of blocks.

In general, wood-concrete chip production process can build on their own, while some users They prefer to buy ready-made raw materials, a preliminary agreement on the amount of faction representatives woodworking companies. If the filler comprises a large number of chips and dust fractions, for their removal recommended shaker.

Chomba (User FORUMHOUSE):

The size of the holes in the sieve must be chosen by experience: Depending on what you have chips (and it is all different). To get started, try ordinary steel wire mesh with a diameter of 1.5 mm cell. And then adjust according to the result.

Wood-concrete chips can contain up to 30% sawdust and shavings carpentry that does not degrade the quality of the finished blocks, but can lead to cement overrun.

Here is a photo of the filler, which has been successfully used in the production.

Wood chips for the production of wood-concrete blocks must meet a number of additional requirements:

• bark content should not exceed 10% of the total weight of the feedstock, and for leaves and needles, this figure should not be higher than 5%.
• For the production of wood chips is not allowed, which has visible pockets of mold and mildew.
• The material should not contain impurities (earth, clay and the like. D.).

It is not permitted as mixing wood chips with snow or ice.

If the production function all year round, the temperature on the shop floor should be stable and should not fall below + 12 ° C.

An important factor affecting the quality of wood-concrete blocks recognized humidity chips. From it depends directly on the strength of the finished products.

car-lover (User FORUMHOUSE):

With dry chips to work much easier. It is less sugars, and they behave predictably. Wet chips each time is different in its properties, so you have to constantly react to changes. The most capricious turns chipsWaterlogging of fresh forest logging and timber obtained after prolonged rains. Of such chips to make quality power extremely difficult.

Sugar - a constant attribute of wet wood (dry wood chips almost does not contain in its composition of sucrose). And sugar is known to adversely affect the cement hardening process. For example, if we add to cement only 0.05% sugar (based on total cement weight), the strength of the daily cement slurry falls to near zero. Thus after 3 days concrete on the basis of such a solution will collect only 50% of the calculated strength.

The problem of the appearance of sugar in the composition of wood-concrete chips is solved in two ways:

• Raw materials for the production of wood chips (wood waste) 3-4 months dried outdoors.
• A ready-made, but overmoistening chips are treated with special additives (e.g., lime).

Conclusion: The dry chips, in any case, would be preferable, but we shall return to the subject of chemical additives.

Cement

For the production of wood-concrete blocks best suited M500 grade cement and above (minimum - M400). But at least it is not necessary to navigate, because the quality of cement in Russia, tend to be somewhat lower than that stated by the manufacturer. Therefore, buying a cement M500, you actually become the owner of the material, the characteristics of which are close to the mark M400.

Chemical additives and mineralizers

Without pretreatment of wood chips wood-concrete special reagents degree of adhesiveness with cement may be unsatisfactory, and the strength of the finished articles - very low. Therefore, the technology provides for the impregnation of the filler with an aqueous solution on the basis of special chemical additives and mineralizing.

a991ru (User FORUMHOUSE):

The main task of mineralizer is to remove sugar from the wood chips. But the main task of the chemical. additives is to accelerate the hardening, increasing the strength of the material and only then - the mineralization speed chips.

Simply put, chem. Additives to be used in those cases where a quick solidification of the mixture (e.g., in an immediate demolding blocks). If the technology is used, implying stripping block some time after pressing, the use of quick lime (GOST 9179-77) as a mineralizer will be optimal this.

Quicklime is considered the best wood for mineralizer. It effectively neutralizes the sugar, but, unfortunately, does not speed up concrete hardening process.

a991ru:

If you lay the blocks in the form of more than 4-5 hours after production, the working version will be pre-soak chips in quicklime, and then kneading such chips using a small amount of cement and quick lime (50 kg / m3). It is quite possible to do without any chemical. additives.

Members FORUMHOUSE recommended to add a batch of 50 to 100 kg of lime per 1 m³ arbolita finished (if not to use further additives). The precise amount is determined empirically.

Presoaking lime used filler weak solution concentration.

Kostyan32 (User FORUMHOUSE):

To eliminate sugars wood raw material is kept 3-4 months or more in the open air, or organic lime filler was treated with a solution of (calculated: 2-3 kg of lime per 1 m³ filler and 150-200 l water).

User MapasanFor example, practicing soaking wood-concrete slabs (for pouring monolith) in the well with the dissolved lime dust. By the time this method of mineralization takes 12 hours and is carried out on the eve of the batch.

If stripping units will be produced immediately after forming, then no chemical additives with properties both of mineralizer and hardening accelerator, can not do:

• Sulfate alumina (chemical synonyms: aluminum sulphate or aluminum sulphate) - effectively neutralizes sugar and accelerates the hardening (setting) of concrete (the material must comply with GOST 5155–74);
• Calcium chloride (HK) - mineralizer effectively accelerating setting blocks (must comply with GOST 450-77).
• Sodium water glass (LGL) - has a shielding effect (locking sugar in the internal structure of the filler, it increases strength arbolita) in addition, LGL accelerates hardening cement increases the fire resistance and a good arbolita antiseptic (the material must comply with GOST 13078–67).

List of chemical. additives used for the manufacture of wood-concrete blocks, is much wider. We have listed only those that are most commonly used in practice.

The amount of additives is calculated as follows: 10... 12 kg per 1 m³ arbolita (if used Larch chips, the amount of additives increases by a factor of 2).

In the VISITOR 19222-84 contains information about the possibility of combined use of various chemical additives. For example, alumina sulfate to be used in conjunction with lime, and calcium chloride - with a liquid crystal. But this method of mineralization has its opponents, so in the process of development of the technology better to experiment with single supplements.

• When using dry and mature chip HC can be added directly in batch (without soaking). When using fresh and moist filler, it should mineralize (using pre-soaking method), and then add HC in the batch. User a991ru recommends preliminary soak for 2 days, using a calcium chloride solution with a concentration of 3 kg / m³.
• Sulphate of alumina is suitable for both dry and wet wood chips. Provisional mineralization when using this additive may be omitted.
• In accordance with the waterglass CH 549-82 (ZS) to be used in the same amounts used in any other chemical additives. The wood-concrete mixture LLL added after the chips and other chemical additives (cement but before the introduction). waterglass module can vary - from 2.4 to 3.

In fact, many manufacturers arbolita registered on our website, completely abandoned the use of liquid glass. Moreover, according to them, such failure will not lead to a marked reduction units strength. However, the usefulness of this additive can only be determined from practical experience.

Chemical additives (including water glass) should be made in the mill base in the form of an aqueous solution having a recommended density. Density is measured by densimeter. To a solution of calcium chloride, for example, it should be roughly equal to - 1.084 g / cm³ (concentration - 10%), and for waterglass solution - 1.3 g / cm³. Aluminum sulfate is diluted in the ratio: 9 kg additive per 100 liters of water.

We have listed the parameters of the solutions dictated by technological requirements. In practice, the density of the solution often does not meet the specified parameters (someone doing it anymore, and someone - on the contrary).

If you decide to use a combination of various additives, their total amount should not exceed 4% by weight of cement in Arbolit. For example, 2% of calcium chloride and 2% aluminum sulphate.

A little more about how to choose the right supplement.

ShoTBobR (User FORUMHOUSE):

If you need the best mineralizer, this is aluminum sulfate. If you need hardening accelerator, then add calcium chloride. If you want to protect the cement from exposure to sugar, but do not want it to dissolve, then add the liquid glass.

Water

For the production of suitable arbolita water, the basic parameters of which are regulated by GOST 23732-79 - "Water for concrete and mortar." In practice, a pipe and process water, as well as water from boreholes, wells and other available sources.

The main focus in the preparation of water for arbolita should be turned on its temperature: for better setting cement aqueous solution fed to the mixer should have a temperature - from +12 to + 15 ° C and higher. How to ensure that temperature - each manufacturer decides independently. Someone heats the water, someone in the workplace has a large tank in which the water during the storage time to heat up to the desired temperature. Incidentally, dry calcium chloride, when dissolved in water, due to its chemical activity is able to significantly increase the temperature of the aqueous solution.

The proportions of the wood-concrete mixtures

Strict adherence to the proportions - a 90% success rate in the production of solid wood-concrete blocks.

Strict rules governing the amount of cement and wood-concrete chips on 1m³, does not exist. There is only recommended proportions that depend on what brand and what class of material strength to get eventually. According to the strength class (V0,3 - V3,5) wood-concrete blocks can be divided into 2 categories - thermal insulation and construction.

Each class has its own indicator of the compressive strength:

• V0,35 blocks have a compression strength - 5.1 kgf / cm².
• V0,75 - 10.9 kgf / cm².
• V1,0 - 14.58 kgf / cm².
• V1,5 - 21.8 kgf / cm².
• V2,0 - 29.16 kgf / cm².
• V2,5 - 36.45 kgf / cm².
• Durability of blocks is V3,5 about 51 kgf / cm².

After reading the above parameters, one can calculate the approximate content of cement that will be needed to achieve the required strength. For example, for obtaining structural arbolita minimal amount of cement is 300 kg (in 1 m³ of finished blocks). In practice, users of our portal added to a mixture of 300 to 400 kg of cement M500.

a991ru (User FORUMHOUSE):

At least chips on cement, you will have - 300 kg (M500). If you put less than, the results may not be very much.

Estimated consumption dry aggregate must correspond to the data shown in the following table.

As can be seen, the flow rate of dry wood-concrete chips is approximately 220 kg per 1 m³ structural arbolita. If the chips have a moisture content of 50%, then the batch must be put 330 kg of filler (its charge is always proportional to the humidity).

Water is added in the following amounts (provided the use of dry filler).

Water flow (as well as the flow of filler) should be calculated based on the chip humidity. For example, if the relative humidity of the filler - 30%, for the manufacture of 1 m³ arbolita strength class V2,0 we need chips 286 kg (220 kg + 30%). It should be taken into account that already contains the wet filler in the structure 66 liters of water. Therefore, in the kneading we need not expend 380 liters of water (as specified in the table), and 314 l (380l - 66l). You can even less, because to add water to the mix, you can always remove it and there is no longer work.

The optimum ratio of the components is determined empirically: after the trial batches after molding blocks and measuring the strength of ready products.

mixing technology

Mixing is done in the following order:

• Preparing an aqueous solution with the required amount of chemical additives.
• The mixer is filled with the required amount of chips.
• The running mixer, uniformly wetting the entire filler mass are filled with solutions of chemical additives and the necessary amount of water.
• The mixer uniformly fed cement and water is added if necessary.
• It is thorough stirring mixture of (not less than 3 minutes).

Lech-chik (User FORUMHOUSE):

First chips is filled, then the additive. Lime milk - at least, but after it has water glass (if it is at all necessary to add). Then cement, and then water (if still necessary).

Once in the mixer pours cement, water to be added only in extreme cases. Indeed it can lead to cement paste with the filler surface washout and decrease blocks strength.

After stirring, the mixture to be distributed in forms for 10... 15 minutes. If this is not done in a timely manner, instead of high-quality units you get a defective building material.

Wood-concrete mixture in its consistency should be moderately sticky and crumbly. If a ball in the palm compress the mixture it should keep its shape without separating out the cement slurry.

About what are the ways of molding wood-concrete blocks, what equipment is used to manufacture them, as well as warehousing and storage features of finished products, you will learn from the second part of this article. Look for updates on our website.

This article is dedicated to the production of wood-concrete blocks, but many users are interested in our portal Construction of houses from monolithic arbolita. Learn more about this construction technology, you can visit the appropriate section of our forum or read an article dedicated to non-standard building materials. section on principles, techniques and methods of production arbolita It will allow you to take part in the deliberations of the questions and introduces the users, which in practice have mastered the production technology.

Discuss the article and read other materials devoted to country life you can on the websiteFORUMHOUSE.

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