Foam concrete production: from industrial to hand-made. Foam block production, video. Installation type UPB

In the beginning, I would like to say that contrary to the prevailing opinion that foam concrete is concrete with air inside, let's say, these are balloons, the shell of which is ordinary concrete.

The technology for the production of foam concrete is of four types: with the help of a foam generator, with overpressure, turbulent resonant cavitation dispersion, using a foam generator and a dispersant. Let's consider each of them in detail, because each has its own pros and cons.

Any foam concrete must include water, cement and a foaming agent. As a filler, you can use quartz sand (without clay), ash disposal, microsphere, waste water treatment and even dump slag from metallurgical production. As a rule, all non-autoclaved foam concrete, in contrast to.

1 Preparation of foam concrete using a foam generator(the most ancient")

The method is as follows: in a low-speed mixer, as a rule, with a horizontal rotor, a cement-sand mortar is prepared. Separately, a foam solution is prepared in the foam generator. The foam is then mixed with cement mortar.

The pressure at which air entrainment (foaming) is carried out is equal to atmospheric.

A plus:

the ability to use all types of foaming agents: from protein to synthetic.

Minuses:

the presence of unstable bubbles in the foam and its partial destruction (sediment) even before the setting period;
impossibility of obtaining low density foam concrete (grades below 500);
impossibility of high-quality dispersed reinforcement to obtain fibropene concrete;
installations of this type are very cumbersome and do not make it possible to carry out monolithic casting at the construction site.

Outcome: As a rule, blocks obtained by this method have an inhomogeneous structure and are susceptible to cracking due to the internal stress of the material itself. In one batch, the specific gravity can vary up to 100 units.

2 Preparation of foam concrete under overpressure

The method developed by MGSU (Moscow) in 1979. Its essence is that all components are loaded into a baro mixer with a vertical rotor and pore formation occurs at excessive pressure.

Pros:

this mixer can be used as a foam concrete pump, since the foam concrete is removed from the mixer through a hose;
these installations are of different sizes. Small ones (up to 200 liters) can be transported to the construction site.

Minuses:

impossibility to carry out dispersed reinforcement of foam concrete with fiber;
high coefficient of variation of the density of the mixture from batch to batch;
mandatory presence of a compressor;
only synthetic foaming agent is used, and in large quantities;
at the expense of high blood pressure Rapid wear of the rotor seals occurs in the mixer flask.

Outcome: At the expense of high pressure, the foam concrete obtained by this method "crushes" when removed from the mixer. The blocks turn out to be unstable, they crack even in the warehouse and they do not tolerate transportation to the place of masonry extremely well.

3 Preparation of foam concrete using the technology of turbulent resonance cavitation dispersion

Cooking is carried out in open mixers with a vertical rotor. Due to the high revolutions and guides inside the mixer flask, the solution (mixture) is thrown onto the mixer stacks. It turns out a funnel (cavity). At its bottom, a zone of low pressure (up to 0.8 bar) is formed. The mixture is constantly circulating vertically and, in order to compensate for the difference with atmospheric pressure, begins to "absorb" air into itself. This process is called the "physical effect of turbulent cavitation". Moreover, this process occurs evenly.
When the parameters of the installation are coordinated in a special special way, the phenomenon of resonance in the liquid medium occurs at the boundary of the cavity. As a result, cement and sand particles are crushed, and air bubbles are also minimized.
Kneading lasts no more than 6 minutes (with a good foaming agent).
Installations:

pros:

stable foam concrete mixture. Its bubbles do not burst (finely dispersed closed porosity), which increases the thermal resistance of the material by 1.5 times compared to the requirements of GOST;
due to the closed pore, this foam concrete is waterproof (floats in water). Its water saturation is not more than 11%;
the coefficient of variation in density from batch to batch is not more than 4%;
you can use sands with a fineness module 1 - 3, without preliminary grinding;
the possibility of using fibers with a fiber length of up to 70 mm;
all installations are mobile and can be used for filling monolithic walls;
the possibility of using cements of "low" grades (ШПЦ 400);
low shrinkage of foam concrete when it dries;
the possibility of obtaining foam concrete of "low" brands, up to 100.

Minus:

the unit works only with a good synthetic foaming agent.

Outcome: Foam concrete obtained using this technology can comfortably transfer transportation. It can be put on glue, with a layer thickness of up to 3 mm. Due to the use of fiber, there is no "cobweb" on it.

4 Production of foam concrete in a continuous way using a foam generator and a dispersant

Foam concrete using this technology was produced only in laboratory conditions. Unlike the first method, there is a high-speed in-line mixing of a small volume of a mixture of foam and cement-sand mortar. This technology provides for the mandatory presence of a foam generator, a metering unit for mortar mixture and foam flows, and a gerotor pump.

Minus:

large coefficient of variation of densities (15 - 24%). Using this technology, it is impossible to obtain fiber-reinforced concrete, due to which it has a high probability of cracking.

A plus:

these installations can produce ultra-light foam blocks in large quantities.

After considering all the cooking technologies, let's focus on the general the advantages and disadvantages of this material... For comparison, you can see the "" described earlier.

Among the common advantages of foam concrete, It should be noted:

To organize the production of foam concrete does not require large investments and huge workshops.
Production does not require high costs energy.
It is possible to fill floors, roofs and monolithic walls (with certain technologies).
The possibility of fibrillation, thereby increasing strength characteristics, on average by 25%, without increasing the density.
Good workability of the material.
Due to the fact that the pores in the foam are closed - low moisture and vapor permeability. Foam concrete is not blown by the wind.
Due to the fact that cement is used as a binder, over the years, foam concrete only gains its strength characteristics, and does not lose them, like aerated concrete. For comparison;
Due to the fact that foam concrete is not aggressive to metal, it is possible to make large construction elements from it - lintels, floor slabs, etc.

Today, the production of aerated concrete blocks is the most popular among the production of lightweight aerated concrete, this success explains not only simple technology production of foam blocks, but also the output of a high-quality and, in a sense, a unique product. Only such products contain the positive of all traditional materials used for centuries in private and civil construction, so how can you create such a versatile building material?

Manufacturing technologies

Foam concrete blocks can be made by means of two technologies: casting and cutting, it can also be autoclaved and natural aging. During autoclave hardening, the foam concrete mixture is aged in special dryers - chambers at a set humidity and temperature, so, first things first.

Casting

Distinctive features of this production technology - the finished mixture is poured into previously prepared forms, the sizes of such forms can be varied. With this type of manufacture, foam blocks can be sustained both with the help of a steaming chamber and on natural drying. A better quality foam block is considered autoclaved, but if you create optimal conditions in the place of aging, you will get an equally high-quality product.

A concrete mixer, but not an ordinary one, but a special one, its secret is in the inclined blades, which prevent the foam from breaking during mixing. A hose for supplying the mixture or a special container with a volume equal to one batch, but to move it around the workshop, you will need a crane-beam, a steam chamber or a place for holding them, a plastic film. The best option is to purchase a special mini-plant as a whole, it will avoid a large number marriage. As a rule, one goes to such a plant detailed instructions, and selection of the composition foam concrete mix of various densities, in some enterprises selling such equipment, field specialists are attached to it, who are setting up the process. In the future, the production of blocks by means of such factories will minimize the scrap rate due to 80% automation of the production process.

Raw materials

Most a good option, combining the principle of "price - quality" - this is cement M 400 D 20, only if it fully confirms its brand in quality, otherwise it is not a durable foam block.

Sand

Size module 0.02, without debris and foreign bodies, it is important that it has a moisture content of no more than 5%. If the indicator is higher, then before letting it into the construction site, you need to dry it thoroughly. The fact is that when mixing, the sand gives up this moisture to the mixture, and the water-cement ratio increases accordingly, and under such circumstances there can be no question of a high-quality mixture.

Which one is more suitable for your production depends on the type of equipment.

Water- usual lead-in

The reinforcing element will avoid cracking.

The optimal selection of the composition of the mixture is revealed empirically, to identify a high-quality mixture, you need it to have the following data:

Assembly and lubrication of molds, for this purpose, you can use ordinary waste machine oil. It is better to lubricate with a spray gun, so the layer of lubricant will turn out to be as thin as possible.
Cooking begins by mixing water and fiberglass, if added already in concrete mix, then the fiber will not completely dissolve, and the reinforcement effect will be weak.
Next, cement is added to the mixer first, then sand.
While mixing is in progress, we prepare the concentrate, for this we add to the finished foaming agent required amount water, mix and pour into a special container of the foam generator.
After homogeneous mixing of cement with sand, we generate foam, it is important to ensure that it is homogeneous and stable during feeding.
Everything is mixed for no more than 3 minutes, the main thing during this time is to achieve a homogeneous mixture.

Filling shapes

You can use a screw feed of the mixture through a hose, or you can use a bucket, in the first case, the blades of the auger break up the foam and losses occur not only in the volume of the finished mixture, but also in.

Holding

With autoclave production - no more than a day, but with natural drying, in order for the foam concrete to be more reliable, it is recommended to wrap the forms with insulation and cover plastic wrap... On average, exposure is a day.

Removing the formwork of products and storage at the place of holding

After 2 weeks of drying, the blocks are stacked on pallets and sent to the sale. Many neglect this stage, but in vain, if fresh foam blocks are immediately put into a construction site, then under load they can shrink or partially collapse.

Cutting technology

It differs from the previous method of pouring the mixture. The finished foam concrete is placed in one large formwork, where it gains its initial strength, after which this monolith is freed from this form and cut into blocks with a special machine. In all other stages of production, both technologies are identical.

Foam block production, video

Conclusion

The main principle of the production of foam concrete blocks is compliance with all technology rules and quality standards. Indentation from them is fraught with low-quality products and a high percentage of rejects.

Foam concrete is a cellular concrete with a porous structure due to bubbles distributed throughout the volume, resulting from the hardening of a solution consisting of cement, sand, water and a foaming agent.

In the 19th century, builders mixed bovine blood into a cement-lime mortar, and the blood protein, reacting with the solution, formed a foam. Due to the difficulty of obtaining a large amount of foaming agent, then foam concrete did not spread. Foam concrete was “discovered” anew in the thirties of the last century. At that time, a Soviet scientist, experimental builder Bryushkov, added a soap root to the cement mortar. Over the years, specialists in the production process began to try to mix cement with various chemical additives - foam and gas-forming substances, namely: with aluminum powder, with glue-rosin solution.

Foam concrete production technology

general information

Its manufacturing technology is based on mixing pre-prepared foam with mortar mixture... As for the concentrate of the foaming agent and water, when receiving the foam, they are dosed by volume. After that, the ready-made solution is mixed and, thus, a foaming agent for foam concrete is obtained. Further, the production of foam concrete is as follows: the foam concentrate is fed into the foam generator, in which the foam is formed. After that, the foam from the foam generator is transferred to the concrete mixer and this mixture is mixed for about three to five minutes. Then, the ready-made foam concrete is transported through a flexible hose to the place where it is laid in a mold or formwork.

Component consumption during production

The preparation of 1 cubic meter of foam concrete requires 500 kilograms of cement. For the preparation of foam concrete with a density of 300 kilograms per cubic meter you need 270 kilograms of cement. Let's look at what materials are needed for the preparation of a foam concrete mixture. First, there is cement. Second, placeholders. Large aggregates are:, but gravel is not needed for production. Sometimes it is possible to add a lightweight aggregate such as expanded clay. In this case, the strength of porous concrete increases by about 100-200%. Small aggregates are natural or crushed sands. And the most preferable for production is considered river sand... This filler must be absolutely clean, free of various inclusions.

For laying, sands of a fine fraction of about 0.2 millimeters are used. As for clay inclusions, they should not exceed 3 percent. Third, water. Aerated concrete production requires the use of water without any verification. The water content in porous concrete consists of the calculated amount. So, before adding foam, the water-cement ratio of the solution must be at least 0.38. If the water-to-cement ratio is too low, the foam will have a higher bulk density. This can happen as a result of the fact that the concrete during the production process will take the water required for chemical and physical interactions from the foam, while the foam will partially break down, and this will lead to a decrease in its volume in the foam concrete mixture. The most optimal ratio is between 0.4 and 0.45. In this case, the water temperature should not exceed 25 degrees.

Experts advise using protein foam concentrate as a foaming agent. This substance must be stored in hermetically sealed wooden or plastic drums. Such barrels must be hidden from direct contact with them. sun rays... And also they should be stored at a temperature not higher than +30 degrees. Foam concentrate from the moment of preparation can be saved from 15 to 30 days.

Getting a foam concrete mix + video how to do

When preparing the mixture, first of all, sand is poured, after which cement is added and everything is thoroughly mixed until a uniform color of the mixture is formed. It is important enough to distribute the cement well in the sand. Then water is added to the mixture in the amount indicated in the selected production recipe. The mixture is stirred until a homogeneous plastic mass is obtained.

When producing aerated concrete, special attention should be paid to the mixing quality of the components. Only a uniform distribution of cement in the sand will make it possible to obtain the optimal quality of aerated concrete. After all the above, using a foam generator, a certain portion of foam is fed through a hose to the mixer, where for 120-180 seconds it is mixed with the previously prepared cement-sand mixture... If the specified density is controlled in production, then it is quite easy to obtain the required compressive strength of the foam concrete. Cast foam concrete, like any other that is bonded with cement, must create a temperature and humidity regime. This is done, on the one hand, to maintain the process of cement hydration, curing, on the other hand, it lowers the exothermic temperature and prevents cracks from forming in concrete. Because of this, it is recommended to cover immediately after laying the mixture. concrete surface plastic wrap.

How to do video:

Areas where aerated concrete is used

This material is used on roofs and floors as heat and sound insulation. Foam concrete itself is not a structural material. In addition, it is used for tennis courts and filling voids in brickwork underground walls, insulation in hollow core blocks and any other filling where high insulating properties are required. Areas of use of foam concrete are: the production of building blocks for low-rise construction of houses and partitions, monolithic housing construction, heat and sound insulation of walls, floors, slabs, ceilings, filling void spaces.

Foam blocks are quite simple to manufacture, so set them up home production not difficult. To do this, you just need to buy everything necessary materials and equipment. Moreover, some units for the production of foam concrete blocks can be made independently.

General description of the material

Foam concrete is called concrete, which has a cellular structure. These properties are achieved by the presence of closed air bubbles in the thickness of the material. Therefore, foam concrete blocks have low density and thermal conductivity.

They are very often used both as heat-insulating materials (D200-D500 grades), and structural and heat-insulating materials (D600-D800 grades) or structural (D900-D1600) materials.

Foam concrete is especially often used in low-rise construction or when erecting interior partitions... It handles very well and can be trimmed to suit the desired building parameters. Foam concrete blocks are manufactured in accordance with standard dimensions - usually 200x300x600 mm or 100x300x600 mm.

When using foam blocks in private construction, you can get the following:

low material cost;
excellent thermophysical characteristics;
ease of processing and installation;
low weight of the blocks, which does not create additional load on other structures;
environmental friendliness of the material.

The disadvantages of foam concrete include its low strength, the ability to absorb moisture from environment, significant shrinkage.

Features of the production of foam blocks

In order for the profit from the production of foam blocks to be high, this issue should be taken seriously. First of all, you need to choose a method of making the material - classic or autoclave. In the first case, it is necessary to make an ordinary cement mortar, into which air is supplied with the help of a foam generator. After thorough mixing, the mixture enters the prepared molds, where it reaches its design strength.

When using the autoclave method, all the components of aerated concrete are mixed under significant pressure. The finished solution is fed into the molds through a nozzle.

There is also another technology for the manufacture of this material - mixing dry components with subsequent mineralization. It is quite complex, therefore it is mainly used in mass production.

Necessary equipment

Necessary equipment for the production of foam blocks at home:

concrete mixer. You can also use special installation for the manufacture of aerated concrete... It implies a complex unit, which includes a baro mixer, an adapter for a sleeve through which the prepared solution is poured into molds;
compressor. This setting required to submit compressed air in other units - a steam generator device, a mixer for supplying a ready-made solution;
steam generator. This unit produces a special fine-porous foam, which consists of water, air and a special foaming agent;
form. This equipment for the production of foam concrete can be made independently from plywood, chipboard or ordinary edged board.

Foam generator for foam concrete

How much do you need to invest to start a business?

If you plan to establish the production of foam concrete blocks only for your own needs, you can get by with less powerful equipment. In this case, you can buy an ordinary concrete mixer, the average cost of which is 3000 rubles. It is also necessary to additionally purchase a foam generator with a compressor for 20 thousand rubles. If you plan to establish a business for the production of foam blocks, it is more expedient to buy a ready-made set of equipment and forms. In this case, you can use not only new units, but also used ones (in good condition).

Ready-made foam concrete plants are very easy to use. They borrow small area- about 2.5-5 sq. m depending on power and standard configuration... Also, this complex includes a loading grate bulk materials, vacuum gauge, rotary pump, water meter, hoses, control cabinet. For home business there will be an ideal model PBU-300, average price for which is 130 thousand rubles.

It has the following characteristics:

working volume is 300 l;
productivity - 0.9 cubic meters m / hour;
power - 2.2 kW;
weight - 0.38 t;
dimensions - 1.7x1.5x0.85 m.

What to do with forms?

Forms for foam blocks can be made independently, but it is very difficult. It is very important to monitor the accuracy of all parameters so that the resulting material has ideal dimensions. Therefore, for a home business, it is best to find used forms. Their cost will depend on the capacity and material from which they are made. On the market for building materials and equipment, you can find approximately the following prices:

steel molds (36 pieces), where the cell size is 600x300x200 mm - 32 thousand rubles;
steel molds (22 pieces), where the cell size is 600x300x200 mm - 10 thousand rubles;
forms made of plywood (22 pieces), where the cell size is 588x300x188 mm - 6 thousand rubles;
one plastic mold with dimensions 390x190x288 mm - 250 rubles.

The cost of manufactured foam concrete blocks

For example, to build a house you need 20 cubic meters. m of foam concrete blocks. For their production, you need to buy a concrete mixer, a foam generator and plywood molds. In general, about 29 thousand rubles should be spent on the purchase of all equipment.

The cost price of 1 cubic meter m of blocks is determined by all the necessary costs for their manufacture:

materials - cement, sand, foaming agent. To obtain 1 cubic meter. m finished products you need to spend 720 rubles;
electricity - 11.25 rubles;
equipment costs - 29000/20 = 1450 rubles.

It turns out that the production costs of 1 cu. m of foam blocks are 2,181 rubles. The final cost of the material can be reduced by purchasing all materials in bulk at a wholesale price and leasing the equipment after the end of construction.

Professional equipment

When selecting equipment for the production of foam blocks, you should pay attention to mobile mini-factories or stationary conveyor lines.

The first type of device includes a concrete mixer with an adapter, a compressor, a steam generator, a working platform and a batcher. When using such a mini-plant, the ready-made solution is manually distributed into the forms, and after setting, it is removed from them and sent to the autoclave. After final drying, the blocks are completely ready for use. This equipment is delivered to the facility as a complete complex. It can be installed without difficulty and does not require commissioning.

As a result of the production of blocks using mobile mini-factories, material of average quality is obtained. Also, the disadvantages of this equipment include a significant consumption of foaming agents. To obtain a product with optimal characteristics, you need to carefully approach the recipe for the blocks. With the wrong selection of the necessary components, the material will turn out to be of poor quality.

Stationary conveyor lines differ from the previous equipment with a large capacity. It is able to work around the clock, providing a productivity of 5-12 cubic meters. m / hour.

Typically, these conveyor lines are equipped with the following units:

mixing complex, which is additionally equipped with a pneumatic valve and a pump;
foam generator with compressor;
water dispenser, which is equipped with automatic system management;
dispenser for binding materials;
conveyors for sand and cement;
Remote Control;
vibrating sieve.

Considering all the features of the production process for the production of foam concrete blocks, both on a small and a large scale, it is clear that this is a very profitable business. This material is popular in the market, so there will always be a demand for it among buyers.

The use of foam concrete has more than fifty years of history. The operation of structures with its use has already shown the reliability and durability of the material. Foam concrete has high soundproofing properties. Today we will look at the features of the opening own production of this building material.

What is foam concrete

Aerated concrete is concrete with a cellular structure, which is formed by closed air bubbles. This material has low density and thermal conductivity. It can be applied like thermal insulation material(grade D200 - D500), structural and thermal insulation (D600 - D800) and structural with low thermal conductivity (D900 - D1600).

The brand of foam concrete indicates its density. For example, D400 aerated concrete means aerated concrete with a density of 400 kg / m 3. Foam concrete is produced in accordance with GOST 25495-89 “Cellular concretes. Technical conditions". The low density of foam concrete leads to low consumption of materials for its manufacture. For this reason, the cost of foam blocks is significantly lower than that of concrete blocks. The use of such materials is especially beneficial for low-rise construction and the construction of internal partitions.

Foam concrete is very easy to process. It can be cut ordinary hacksaw hammer nails into it. Working with aerated concrete on a construction site has a lot to do with woodworking. Foam concrete blocks are the same foam concrete, formed in the form of parallelepipeds. Foam blocks are made as standard sizes(200 * 300 * 600 mm or 100 * 300 * 600 mm) and larger. At self-production the size of the foam blocks is determined by the size of the selected shape.

The appearance of foam blocks

Advantages of using foam blocks in construction:

low cost and, accordingly, high profitability of production;
high thermophysical characteristics;
ease of processing;
the opportunity to save money during the construction of the foundation due to the low mass of the walls, as well as lower transportation costs;
environmental friendliness.

Foam concrete, like any other material, is not without drawbacks that should be considered when using it. Its strength is significantly lower than that of concrete, and even more so reinforced concrete, it does not work in bending, has a relatively high water absorption and permeability, gives significant shrinkage (it is recommended to hold up to one month before use). But at the same time, the production of foam blocks as a business can bring a fairly high profit.

Production

The production of foam concrete, despite the relatively low cost of factory foam blocks, is very tempting to produce them at home or in a mini-factory.

There is a common misconception that aerated concrete can be produced simply by adding a blowing agent to a standard concrete mix. This is not true.

The production of foam concrete blocks is carried out mainly by two methods. The classic method is to cook cement mix(recipes are given below). Foam is fed into the finished mixture from the foam generator and after mixing, the foam concrete is poured into molds. According to the autoclave method, all components are thoroughly mixed in a mixer under pressure. The resulting mixture is squeezed out through a nozzle into a prepared mold. Technologies based on mixing dry components are usually used in mass production.

Form for foam blocks

For the production of foam concrete, Portland cement of a grade not lower than M400 (preferably M500), sifted and washed river sand, and a foaming agent are used. Sometimes additives are added to the concrete mixture that accelerate the setting (for example, liquid glass), as well as improving the structure of concrete (calcium chloride or calcium nitrate). Sand should be used with fine fractions, since large particles quickly settle (sediment), which significantly reduces the quality of the product.