Equipment for the production of foam concrete blocks at home. Production of foam concrete: from industrial to handmade

Foam concrete is a type of concrete that has a cellular structure. Due to the fact that there is air in the cells, the main quality is excellent thermal insulation. This material has such a high fluidity that it is easy to pour it into molds, obtaining blanks of various types.

Comparison table of characteristics

These two characteristics led to a wide development in construction. Various building products are made from it - partitions, wall blocks, floor slabs and much more. This material is also in demand for the manufacture of floors and roofs. It has found especially wide application in low-rise construction.

Foam concrete, the technology of its manufacture is so simple that, if desired, it is easy to reproduce even at home.

The whole production scheme is divided into 3 stages: production of a cement-sand mixture; preparing a foaming agent solution and obtaining a mixture.

Depending on what density the material needs to be obtained, the proportions of the constituent components are selected. The technology of preparation, depending on the ratios of sand, cement, water, as well as foam concentrate or foam, makes it possible to obtain foam concrete density from 200 to 1500 kg per 1 m 3. When preparing medium density, 1:1 is provided. Moreover, for each kg of cement, 3-4 g of foam concentrate is taken.

Cement-sand mixture

The cement-sand mixture for the preparation of foam concrete is prepared similarly to that used in the production of conventional concrete. Portland cement grades M400 or M500 are selected for it. The sand used, having a fineness modulus of not more than two units, must be free of clay impurities, as they will prevent the adhesion of cement and sand. For the preparation of a cement-sand mixture, the usual tap water, which does not contain acids and salts in its composition.

Types and expediency of application

The foam concentrates used in the preparation are subject to certain requirements, the main of which is a technical and economic indicator. In monetary terms, regardless of the manufactured foam concrete, its cost should not exceed $ 2 per 1 m 3 finished products. A more expensive foaming agent leads to an increase in the cost of foam concrete. Moreover, he is not able to increase the quality of products in proportion to the increased cost.

Regardless of the batch and release date, the foaming agent must have the same properties so that you do not have to constantly reconfigure the equipment in the production line, which, in turn, can lead to a decrease in the quality of the finished product.

This component must have a sufficient shelf life. If its shelf life is less than one year, then during the production process it will be necessary to constantly buy the missing amount in small batches, which is economically unprofitable. In addition, at the end of the construction season, preparation volumes are reduced, and the foaming agent may simply deteriorate before the next season.

When choosing the type of foaming agent, you should pay attention to the consumption rate. It should not exceed 1.5 liters per 1 m 3 of the finished solution. This condition is necessary for two reasons. The first is to get more products per batch of the mixer. The second is associated with a decrease in the influence of this ingredient on the properties of the product. After all, with its excess, the time required for the hardening of foam concrete increases, shrinkage increases and strength decreases.

Another requirement that must be observed when choosing a foaming agent is the simplicity of its preparation. It should not consist of many components. The more components in its composition, the more complicated the process of its preparation, associated with difficulties in their dosing. Also, this material should be highly soluble in water.

foam quality

The quality of the foaming agent determines the stability of the foam, which, in turn, largely determines the physical and mechanical properties. Attention should also be paid to the multiplicity of the foaming agent, which should not be less than 10.

The blowing agent must provide sufficient foam stability during the preparation of foam concrete. The resistance factor is determined in the laboratory. The higher it is, the less foam is required for the manufacture of products of a given density and, accordingly, the smaller the amount of foam concentrate. Like any additive, the latter in large quantities can not only slow down, but also completely stop the process of foam concrete hardening. That is why it is so important to use high expansion foam.

And finally, the last one. The foaming agent must comply with sanitary and hygienic standards - be non-toxic, non-explosive and meet radiation requirements.

Solution preparation

After mixing the components of the cement-sand mixture, the prepared foam concentrate solution is added. The most popular in foam concrete technology are synthetic foam concentrates, which can be purchased at construction market. Manufactured industrial way, they allow you to get a more stable and high-quality working solution compared to other.

But the foaming agent can be made independently. This applies to cooking at home. To do this, mix 1 kg of rosin, 150 g of caustic soda and 60 g of wood glue. A mixture of such components is crushed, heated and mixed until completely homogeneous. But it must be taken into account that a mixture prepared according to such a recipe can only be used to obtain foam concrete using a steam generator.

So, adding to the foam concentrate required amount water, a ready-made working solution is obtained.

Cooking scheme

Depending on the type of foaming agent used and the technology adopted, the foam concrete preparation method is selected. But regardless of the method of foaming, any technological process is based on obtaining a heterogeneous system "gas - liquid - solid".

When preparing foam concrete, two types of equipment can be used. In the first case, foam generators are used. In the second - pressure mixers, that is, installations of a cavitation type.

By classical pattern the preparation of the cement-sand mixture takes place in a special container - a forced-type mixer. After preparing the mixture with a foam generator, a foaming agent or foam for foam concrete is added to the same tank. The mixture is ready for pouring into molds after thorough mixing.

The structure of the material is formed by hardening and setting of the binder component. The prepared mixture is transported by means of a pump into a monolithic structure or mold.

Production in a pressure mixer

With foam concrete, the manufacturing technology of which requires a cavitation plant, all the components of the mixture are put into the mixer at the same time, and the supply of foam concrete from it into molds or a monolithic structure is carried out due to the presence of excess pressure in the mixer. With this method, the mass in a sealed mixer is saturated with compressed air.

The technological process of manufacturing this material may include any additional operations that contribute to the acquisition of additional properties. These can be measures aimed at regulating the structure of the mixture, optimizing its composition, using plasticizers, using a blowing agent along with a blowing agent, and the like.

There are other cooking technologies, but at present they are not widely used.

Hardening of foam concrete

Technological scheme of production

Why accelerate curing? The increase in the specified strength of foam concrete is significantly different from that of conventional concrete. The latter gains almost one hundred percent strength during natural hardening. For the same period of time, foam concrete is able to gain only half the strength. It will take him about six months to get the rest.

If in industrial premises the ambient temperature is less than 10 degrees, then the curing time increases significantly, and it takes 2-3 days to remove the block from the mold. To solve this problem, hardening accelerators are used. They may be different. But the simplest known accelerator is calcium chloride. It is added to cement-sand mixture in an amount of 1-2% of the volume of cement contained in it.

There is one point in its application. One of the components of foam concrete - a foaming agent - must maintain the shape of bubbles for a certain time. The accelerator in the form of calcium chloride reacts with it, which can lead to large shrinkage of foam concrete.

Currently, to speed up the hardening process, specially made preparations for foam concrete are used, which can speed up the process by almost 3 times and produce these products at temperatures up to 5 degrees.

Process selection

When choosing a technological scheme, one should be guided by what characteristics of the material are required to be obtained, what types of raw materials are used and what opportunities exist at the enterprise engaged in the preparation of foam concrete. Any technology must be carried out in order to comply with the main condition - obtaining quality material with a well organized porous structure.

In the process of manufacturing foam concrete, such changes occur in the mixture that contribute to the acquisition of its molecular structure by a system consisting of small spherical cells 0.1-2 mm in diameter. The final structure of foam concrete is formed during its final hardening. During the technological process, the density of concrete can be easily adjusted, which is an indispensable quality in the production of material on construction site or in a small business environment.

Pouring methods

On the last step foam concrete is poured into molds, formwork or cassettes. The lubricant used for molds should not contain oil in its composition, since its presence will complicate further puttying and plastering of foam concrete blocks. Ready-made forms to obtain blocks of appropriate sizes are cut on band saw equipment.

On the this moment Another method of obtaining blocks is used - filling in forms. Each of the methods has both its advantages and disadvantages.

With the cassette method of pouring the mixture technological process pretty simple. With the release of products up to 20 m 3 per day, cash investments in equipment will be much less than when using other methods of pouring foam concrete. It is also possible to increase production volumes without significant costs. At the same time, it is possible to produce unique models of blocks, for example, tongue-and-groove.

The disadvantages of this method include low productivity and the use manual labor in large volumes. In this case, the geometric dimensions of the finished block are less accurate, and appearance- not attractive enough.

Another thing is the pouring of the mixture into arrays and their subsequent cutting. With this technology, the resulting dimensions of the finished product are more accurate than with the first method. This method allows the enterprise to produce a large volume of products and easily increase it with minimum investment funds. At the same time, the use of manual labor is low. The disadvantages of this method include the higher price of finished foam blocks and a large number of production waste.

The choice of one or another method depends on the required amount of production. For small volumes, it is preferable to use a simpler pouring into molds, and for larger volumes, a cutting method.

Foam concrete is a popular building material that has good heat and sound insulation characteristics. Self-production foam concrete allows several times to reduce material costs. There are several construction technologies, according to which foam concrete is produced. We offer you to get acquainted with their features and methods of implementation.

Scope of use, types and advantages of home foam concrete

The popularity of foam concrete in the construction industry is explained by its following advantages:

1. Economic feasibility.

The production process does not require special material investments, the material is made from available materials, and the possibility home production greatly reduces its cost.

2. Vapor permeability of foam concrete.

Due to the fact that the material passes air, a favorable and healthy atmosphere is created in the room, mold and fungus do not form.

3. Environmental safety.

Foam concrete is an environmentally friendly material, since no additives are added to it during the production process. toxic substances. The main components are sand, water and cement. Some manufacturers improve performance characteristics material by adding plasticizers and hardeners.

4. The material is light in weight.

This advantage greatly simplifies the process of transporting and laying foam concrete. In addition, such a house does not need a massive foundation, but construction works conducted even in seismic areas.

5. Quick installation.

The use of foam concrete as a building material for building walls allows you to build a house in 2-3 months.

6. High heat and sound insulation performance.

The production of walls from foam concrete reduces the cost of the total cost of the building, as the cost of purchasing heat and sound insulating materials is reduced.

7. High level fire safety.

Foam concrete does not burn and does not support combustion, in addition, it prevents the spread of flame.

8. Versatility of further finishing.

Foam concrete walls are puttied, plastered, sheathed with wood, clapboard or siding. There are no restrictions in this regard.

Among the shortcomings of the material, we note the high porosity, which, on the one hand, improves thermal insulation performance, and on the other hand, reduces strength. Therefore, the transportation of foam concrete is carried out with extreme caution. Walls made of foam blocks are necessarily reinforced in order to avoid the appearance of cracks on their surface after shrinkage. In addition, foam block walls need finishing. The lack of external finishing leads to the absorption of carbon dioxide by the material and a decrease in its strength. quality exterior finish quickly solve this problem. The best option- the use of brick as a finishing layer.

The scope of foam blocks is not limited to the construction industry. The material is used to build walls, load-bearing structures in country houses, residential and office buildings. In addition, foam blocks are widely used in the process of insulating already erected walls, improving sound insulation, during the construction interior partitions. With the help of this material, old buildings are reconstructed and repaired, their number of storeys is increased and sound insulation of floors is improved.

Foam blocks differ in density and in the number of pores in the material. The letter D is used to designate this indicator. The material production recipe directly determines its quality and brand, and these indicators are the main ones in the field of using foam blocks. In relation to the place of application, the material is divided into:

foam blocks, from which internal partitions D100-300 are erected;
heat-insulating material D400-500;
structural and heat-insulating D600-900;
structural foam blocks D1000-1600.

Foam blocks of the highest density have the lowest thermal insulation performance and are used to reinforce ceilings and works constructive purpose. Their cost is much higher than that of D100-300 foam blocks.

Please note that the humidity of the air during the laying of the material should not exceed 60%. Otherwise, a vapor barrier film is applied to the inner surface of the material. For laying the material, both a conventional cement-based mortar and a special glue are used. The use of an adhesive composition has great advantages, since in this case, cold bridges do not form inside the walls. In addition, the amount of adhesive composition for fixing foam blocks is much less than cement.

Do-it-yourself foam block press

The standard two-stage technology for the manufacture of foam blocks involves the use of equipment in the form of:

foam generator and compressor unit supplying air;
mixer, at home, is replaced by a concrete mixer;
molds for pouring the solution and its solidification;
additional devices in the form of a pressure gauge and pumping equipment.

Before starting work, prepare drawings of equipment for the production of foam concrete. Next, purchase the module - the most expensive component. This part of the device converts the foaming agent into a foamy substance, supplying it to the solution.

The feeding module serves as a place for pouring the solution that forms the foam. Any reservoir will cope with this function, right size. Conversion module - recycles the solution, making foam out of it. Dosing equipment - delivers foam in a certain density and quantity, determines the grade of the material obtained.

Among the main parts of the foam generator, we note the elements in the form:

nozzles;
docking flange;
suction pipe;
body part;
displacement chambers;
diffuser.

For self-manufacturing this appliance, prepare two pipes, a pump, a hose, a valve. Also, stock up welding machine and drawings, according to which further work is carried out.

The factory pipe for the foaming agent has a peculiar structure, one part of it has a narrow structure, gradually expanding. Thus, the speed of passage of the liquid through the pipe increases, at the outlet it increases as much as possible.

Next, start making a foam cartridge and a chamber for the turbulent connection of the components. To do this, weld pipes in the amount of two pieces to one pipe. One of them is located in the end part, and the second is a foam supply, with a corner. Make sure that the nozzles are at right angles to the tube.

Install two valves on each of the pipes:

shut-off type - with its help, the supply of the foam former is stopped;
adjusting type - regulates the speed and amount of foam supplied.

Control valves are needed only for initial adjustment, they are not used in the future. Recommendation: the diameter of the side pipe should be twenty percent larger than the end pipe.

The next stage is work on the foam cartridge. The second pipe blank is equipped with a branch pipe, which ensures the exit of the finished composition. A funnel is installed on the outlet pipe, which reduces the rate of exit of the foam concrete mixture. Install a filter inside the workpiece that converts the emulsion into foam. It is possible to buy a ready-made filter or make it yourself from a regular dishwashing brush.

Please note that in this case, use a wire type mesh, not a spiral one. Tamp them along the entire length of the tube, in order to prevent the ruff from falling out, additionally strengthen it with a washer.

Next, the mixing chamber is connected to the foam board. In this case, the installed nozzles are located at opposite ends. To improve the speed of transporting the composition through the pipe, install an element in the form of a nozzle or jet washer between them. Please note that the second option, although cheaper, is worse, as it reduces the efficiency of the device by 30%.

Connect the compressor unit to the end pipe and the connection chamber. Please note that the compressor power must be at least 5 atm, in addition, it must have a receiver, a pressure gauge and a pressure reducing valve.

Place the container on the floor, connect the foam supply hose to the mixer. Connect the resulting installation to a pump that will simplify the supply of foam. This device is not inferior in power to the purchased installation, but its cost is 3-4 times lower.

The next stage is the construction of molds for foam blocks. Suitable for these purposes various materials such as wood, plywood, steel, polymers. The main requirement is to create a solid and even surface that is not prone to deformation. Follow these steps to make a mold:

calculate the size;
create a drawing.

Standard foam blocks in length, width, height in a proportional plan are 4-2-1. By adhering to this ratio, a material is obtained that is suitable for the construction of walls and convenient dressing, without cutting the blocks. That is, with a form depth of 15 cm, in width and height it will be 30 and 60 cm.

In the individual production of foam blocks, thirty forms for a foam block are enough. Mount partitions so that their largest part is located on top. Thus, the foam blocks dry faster and evenly gain strength. It is possible to manufacture multi-level molds.

First, build the bottom of the mold, firmly fix the walls on it and install removable partitions inside. We recommend staying at collapsible version shape, thus, the size of the foam block is changed, if necessary. When making a mold from plywood, connect the parts together with nails and choose its laminated options. Homemade forms allow you to make foam blocks required size and forms. Please note that before pouring foam concrete into molds wooden crafts pre-covered with a film, otherwise, the wood will absorb moisture from the solution and deform the characteristics of the resulting product.

Step-by-step instructions for the manufacture of foam concrete

For the manufacture of foam blocks, you will need special equipment and mixtures. The composition of the solution for foam concrete includes ingredients in the form of:

310 kg of high quality cement;
half a ton of fine sand;
210 liters of water;
1-2% foaming agent in relation to the mass of cement;
modifying additives.

To make a foaming agent at home, mix the components in the form:

150 grams of caustic soda;
1 kilogram of rosin;
60 grams of wood glue.

The foaming agent does not have to be made at home; a variant of ready-made formulations is possible. The instructions for the blower for foam blocks indicate the proportion of addition to obtain a material of one grade or another.

For self-production of a foam concentrate, follow the instructions:

1. Cook adhesive solution. Pour the glue with water in a ratio of one to ten, leave for a day. Next, heat the tank with the composition to a temperature of sixty degrees, stirring constantly, the mass should become homogeneous.

2. Rosin soap is prepared as follows: bring sodium to a boil, add rosin, boil the composition for 120 minutes until smooth. Rosin is pre-crushed.

When the soap cools to sixty degrees, combine the compositions with each other in a ratio of one to six.

Pour the composition into the foam generator to obtain high-density foam. Optimal value foaming is eighty grams per cubic meter. At a lower value, the quality deteriorates. finished material and its thermal insulation properties.

The quality of the foam is determined in this way, fill the bucket with the composition and turn it over. If the foam is firmly held and does not flow out, then the proportions are correct.

The scheme for the manufacture of foam blocks looks like this:

supply of sand with cement;
adding water;
getting the composition into the porizer;
supply of foam concrete into molds.

Please note that quite often the first 3-5 foam blocks do not turn out to be of the desired quality. This is due to such reasons:

the difficulty of adding components in the right dosage;
decrease, increase in water level;
a large amount of foam former;
wrong kneading time;
determination of time for curing;
selection of the material drying mode.

Experimenting, all these indicators lead to the norm. Further recipe for the production of the material is used constantly. Defective foam blocks are used to fill the floor.

Foam blocks of the d900 brand and higher are easier to manufacture, since their composition contains a small amount of pores, however, they have less thermal insulation properties.

Do-it-yourself foam concrete video:

It is quite simple, but in order to establish a really high-quality process, you will have to spoil more than one ton of cement. For a beginner, it is not always clear where to start production. Foam concrete technology is characterized by the presence of quite impressive capital resources at the disposal of a person. This is necessary to create a quality product and deliver it to the market. The foam concrete production technology should be based only on high-quality ingredients and equipment. Only in this case, you can get a really high-quality result.

Due to their reliability, lightness, strength and environmental friendliness, foam concrete blocks are today considered the most popular building material.

The manufacturing technology of foam concrete implies a uniform distribution of air bubbles within the entire mass of concrete. There is such a material as aerated concrete. The technology of its production is largely different from that used for foam concrete. In this case, we are not talking about chemical reactions, but it involves mixing a pre-prepared mixture of foam and concrete. Foam is obtained by whipping active substances that produce a bunch of liquid. It is worth noting that the ease of production is distinctive feature material. The foam concrete production technique involves a series of sequential operations. It is worth talking about them in more detail.

Preliminary preparation of raw materials

Technology modern production foam concrete implies the use of cement grades M400 and M500. Also, clean sand and a certified Russian foaming agent are added here.

The amount of water should be calculated in accordance with the parameters of foam concrete blocks. It should be enough to mix the solution.

Before adding foam, it is imperative to maintain a ratio of cement and mortar of at least 0.38. If you do not maintain this ratio, then in the end you can get a material that will not correspond to the specified density parameters.

This is due to the fact that concrete takes part of the water from the solution, which is used to partially destroy the foam. If we talk about the optimal water-cement ratio, then it should be 0.45-05.

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Foam preparation: features

So, now you can move on to a more detailed consideration of the issue related to the preparation of foam. First you need to soak the previously prepared solution in water in the right ratio. Further, the prepared solution enters the foam generator under pressure. This is where the foaming process takes place. This is done using compressed air, which comes from a special compressor. If we talk about the share ratio of the dissolved foam concentrate, then it is approximately 0.5-1.5 kg per 1 cubic meter of concrete. It is immediately necessary to load at the rate of 4-6 cubic meters foam concrete.

As for the quality of the foam, it can be easily checked. To do this, the bucket is turned upside down. If the foam has White color and does not follow, then the material is prepared really high-quality, and accordingly, you can start cooking directly cement mortar. In fact, the system for the production of foam concrete can be both cutting and casting. Both options are widely used in the modern world.

The cutting technique for the production of foam concrete is considered the most primitive. It involves the use of a huge container, into which the solution is poured. Then, the already finished foam concrete is sawn with a special tool into separate parts according to the specified geometric dimensions. This is done using special cutting machines.

In accordance with the production technology of foam concrete, several types are distinguished. In some cases, apply band saws, and sometimes special strings. It all depends on what exactly is at the disposal of a particular person who is engaged in the production of building material of this type.

There are several undeniable advantages of this foam concrete production technology. The main ones include the following:

There are no chips on all edges and corners of the material, therefore, labor costs for further processing of blocks are significantly reduced.
Great geometry of all blocks. For this reason, they can be installed minimum thickness seam.
There is no lubrication on the surface of the blocks, which contributes to excellent adhesion and improvement of the appearance of the building material. Of course, appearance is not so important. It can always be changed, because in the future additional wall decoration is implied. It is because of this that adhesion has a maximum importance. It greatly simplifies finishing works, that is, plastering.
Possibility of production of foam concrete blocks of the most various geometry. This is achieved due to the fact that the final product has enough big sizes. In this regard, the strings and saws can always be adjusted to the desired pitch. You can always please each specific customer.

It is these advantages that are forcing more and more manufacturers to switch to a similar technology for the production of foam concrete.

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Main production methods

The technology for the production of foam blocks involves the use of three various ways productions. Accordingly, there are 3 types of equipment on the market. These are pressure mixers, special mixers with foam supply and dry mineralization of the foam composition.

Scheme of production of foam concrete: 1 - container for foaming agent solution, 2 - service platform, 3 - compressor, 4 - foam generator, 5 - mixer, 6 - pressure hose, 7 - longline molds.

If we talk about barotechnology, then it implies the direct supply of all necessary components to the mixer in accordance with the dosage. Here a certain pressure value is created. Stirring continues for approximately 3-5 minutes. As a result, already ready mix under pressure is fed into the place of laying the molds. Here ready-made foam concrete blocks are produced.

Dry foam mineralization involves mixing the foam with dry cement and other components. At the same time, the humidity is not artificially increased. It has a constant external climatic value. Next, you should get a foaming agent. For this, the foaming agent and water are diluted in a special vessel. Further, foam is prepared in the foam generator, and it is fed into the mixer. Next, dosing of all other components. Now the foam can be safely served in special shapes for the preparation of foam concrete blocks.

There is also a classic technology for the production of foam blocks. It lies in the most primitive method of obtaining the finished product. Here the mortar mixture is mixed with the foam.

The foam concentrate is mixed in a certain proportion with water.

As a result, the resulting mixture enters the foaming agent. Further, it enters the foam generator. It is here that the final formation of foam occurs.

In a separate container, the components of the solution are dosed separately. As a result, both substances are mixed with each other. Mixing is done in a special mixer. This is where the material enters the molds. This is a classic of the genre. This method is the simplest, therefore it is used by many private manufacturers.

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Some properties of foam concrete

It is worth talking about why foam concrete is one of the most popular materials today. This is made possible by its properties. These include the following:

Excellent thermal insulation. This is achieved due to the porous structure of the material. Its production allows several times to reduce heating costs. This is important in view of the constant rise in energy prices. As for the permissible number of storeys of construction, it is quite high. Today, you can safely build houses from foam concrete up to the 4th floor.
Increased frost resistance, which allows you to build houses from foam concrete blocks, even in the central and eastern regions of the country. As for the cyclicity, it is 35 cycles, and this is a very significant period.
Increased fire resistance. This property allows foam block walls to be used even in the most extreme situations. They are able to withstand up to several hours of direct exposure to fire.
Breathability. This is very important for every home. In connection with these properties, air exchange between the room and environment. This not only allows you to keep warm, but also relieves the walls from various influences of fungus and microorganisms.
The humidity of the blocks does not exceed the value specified by GOST.
Excellent soundproofing properties that will protect all residents of the house from the harmful effects of noise.

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The main elements of the production line

Today, for the correct production of foam concrete, it is imperative to provide a competent technology for its production. Here, without fail, there must be a lot of different devices and devices. These include the following:

Sand storage area. It must be provided with optimal humidity. Of course, it is desirable that the sand always remains dry. This will greatly simplify the process of its production.
Sand belt conveyor. Of course, the supply of this material should not be carried out manually, especially since the organization of the simplest conveyor does not require great expenses.
Sand hopper with auger. In this case, it will be used for portioned backfilling of the material. The auger is exactly the device that will perfectly cope with the task.
The bunker for cement with the screw. Basically, its task is the same as the previous mechanism. Cement must also be supplied to the final product in certain proportions.
Installation for the preparation of material. They were discussed above. The choice depends directly on the desires of a person and his financial capabilities. There are fully automatic units that prepare foam concrete themselves, and there are those that involve human intervention in the process.
Foam generator. This device has also been discussed above. It is needed to make foam.
The form. Most often it is made of metal. This is where all the components come in, which are then turned into blocks.
camera for heat treatment blocks. Without it, the process will not be completed. Here they are kept at a certain temperature. The optimal ratio is from 70 to 80°C.

foam concrete- This is a porous stone that is created artificially and has a porous structure throughout the volume. The pore size reaches up to 3 mm. It is also called cellular concrete. Currently, in the production industry of foam concrete, as well as products from it, there are two main technologies for its production: barotechnology and production using a foam generator. It should be noted that almost the same raw materials are used in both methods, but the differences are both in the method of mixing and in the order of introduction of the basic components. Due to this, the products are of different strength and quality.

Barotechnology

Using the method of barotechnology in the production of this material has both advantages and disadvantages. Products obtained by barotechnology have a low level of strength, but are distinguished by a simpler and less costly process. They do not require expensive equipment and too large premises, and the time for obtaining a conditional unit is significantly reduced. This method of obtaining foam concrete used for these economic reasons. However, if the above qualities are a plus for manufacturers of such building materials, then the consumer receives low-quality products that should not be used in large volumes of construction.

When using barotechnology, in a hermetic mixer introduce the basic components of the stone: sand or fly ash, cement, water, hardening accelerators, foaming agent, and sometimes air-entraining additives. In the technology for the manufacture of mixtures, optionally, they are also introduced additional operations, which are aimed at optimizing the particle size distribution of the components and regulating porous structure, the use of gas and foam formers, as well as the use of functional additives that accelerate structure formation.

Then, under the pressure generated in the mixer, all these components are thoroughly mixed and the mixture is actively saturated with air. This process is called air entrainment.. Under pressure, the resulting solution through the pipeline enters directly into the injection molds. At the same time, the process of atmospheric pressure, which was injected in the mixer with the help of a compressor, stops, after which the foam concrete mixture begins to increase in volume. Visually, this process resembles a shoot yeast dough, which differs only in the speed of "ascension": for the same material at the moment of molding, the increase occurs instantly.

Advantages and disadvantages of the barotechnology method

And now let's take a closer look at the pros and cons of barotechnology for the production of foam concrete. This method is characterized by lower product strength, which is its main disadvantage.. Of course, it is better and more effective to beat more liquid substances. To compare, you need to imagine the consistency of whipped 30% sour cream with milk. Manufacturers are forced to introduce more water into the composition of the mixing, due to which the final strength of the foam blocks is significantly reduced. For a complete hydration process in the production of cement, a larger amount of water is undesirable. The process of hydration is the addition of water, which occurs with the help of chemical reaction clinker components of cement with water. When interacting with water, the cement hardens and turns into the so-called cement stone.

At the same time, in foam concrete, which is produced by barotechnology, fairly large pores. They can be compared to the pores of fine pumice. Air voids in its structure are rarely less than 1-2 millimeters. Naturally, such large pores greatly reduce the strength and bearing capacity blocks in future building designs.

The disadvantage of this method can also be considered the use of synthetic foaming agents., which have low environmental friendliness. The desired mobility of the mixture, without increasing the proportion of water, is obtained by adding plasticizing substances - superplasticizers. Today, not a single modern cement or concrete mixtures does not do without special additives in the production of concrete, which significantly improves the quality of the mixture and regulates the processes of setting and hardening of cement.

Despite the unconditional increase in the quality and mobility of the foam concrete mixture, its use eliminates the use of natural foaming agents, which are used for the production of cellular concrete. It is known that they are obtained in the process of transformation of natural protein macromolecules by hydrolysis in an aqueous solution. In a word, if the consumer decides to build a house from environmentally safe materials, he should initially exclude the use of foam blocks, which are made by barotechnology.

Undoubtedly, essential dignity production of these products by this method is considered lower cost, which significantly increases the economic benefit for the manufacturer. The main advantage of barotechnology is also the use of cheaper technological equipment, which does not require large investments and is organized in any room adapted for this.

If in the application of this technology for producing concrete, all the advantages go to manufacturers, then the description of another method given below can become an advantage in the production of foam concrete to please builders and buyers.

foam generation method

In the first half of the 20th century, the engineer Bayer invented a new method for the production of foam concrete, which differed from barotechnology in that the foam of the product was prepared separately. In its production by foam generation, two stages are distinguished: making foam with a foam generator and mineralization of the resulting foam with cement and sand. Upon receipt of the product using the first method, the main components are kneaded in correct dosage, and the process does not adhere to the principle of changing the water-cement ratio. Due to this, the output products are distinguished by their manufacturability. Main element– foam generator, in this technology is used to obtain finely porous foam from a mixture of air, water and a foaming agent. The latter is used with 20-30% savings. At the same time, despite the scale of production, it is necessary to complete the line with modern and high-quality equipment, which will guarantee high reliability of the products obtained, as well as a long service life.

Here's how the blocks are produced using the foam generator method. Such precisely dosed bulk components as cement and sand are introduced into the mixer, sometimes fly ash can be added as a filler. When replacing sand with the last component, the thermal conductivity of the stone significantly decreases, which, in turn, increases the heat saving of the building. It is necessary to know that those sellers for whom profit is more important than the quality of the products received, use mineral powder and fly ash as a weight additive in their production. The cost of these components is much less than the cost of cement.

After adding the components to the mixer and mixing them, compressed air from the compressor is supplied to the foam generator. At the same time, the personnel must constantly regulate the supply of the working foam concentrate and compressed air, on which the quality of the foam at the outlet depends. This process is no different from the production of concrete. After preparation, the technical foam is fed into a specially made mixer - a foam concrete mixer, the speed of which is not more than 300 rpm. This stage is carried out very carefully, without destroying the resulting foam. Then cement and sand are introduced. This process is called "dry mineralization" technology. And with “wet mineralization”, the foam is fed into a pre-prepared solution of cement and sand. Thanks to the complete controlled process of active mixing of foam with cement-sand mortar, the production of foam blocks is carried out at a higher quality level.

Advantages and disadvantages of the foam generation method

The following are some of the disadvantages and advantages in the foam-generating production process. This method is quite expensive when expensive equipment is used in production, and it takes more time per unit of finished product. Parallel to this, the cost of produced blocks also increases. That is more high price production stems from the high cost of production.

The advantages of this production building materials with a foam generator is a higher quality foam block array. The use of pre-prepared foam helps to produce a product with a correct structure at the exit, thereby avoiding the appearance of large air pockets and aiming for higher and more uniform strength.

It should be noted high environmental friendliness in their production when environmentally friendly foam concentrates are used. Their use in the construction of houses becomes the key to the health of their future residents.

Summarizing the above qualities of the "foam" technology, we can say that this method is rather "for" the consumer, and manufacturers, in turn, try not to choose it. Barotechnology is much more profitable for them and does not require large investments.

To build a warm and environmentally friendly house from hand-made material, it makes sense to master the production of foam blocks at home. This will save money on the purchase of blocks, avoid damage during transportation, make "bricks" right size.

Equipment for the production of foam blocks at home

To make foam concrete blocks, you can not do without a minimum set of equipment and accessories:

foam generator - its performance should be at least 200 l / min;
compressor;
concrete mixer - volume from 250 l;
molds for foam blocks or detachable formwork.

To regulate and control the pressure, it is advisable to connect auxiliary devices and equipment - pressure gauges, pumps.
Forms are made detachable or one-piece. In the first case, they are 2 L-shaped halves of wooden board 20 mm thick, upholstered with sheet metal, or 4 flat steel sheet walls connected with bolts or latches. One-piece equipment is made by welding from a sheet 4–5 mm thick: the walls must be trapezoidal to simplify the removal of products.
It is more convenient to use multiple forms made of moisture-resistant plywood, metal or plastic, which are a frame with cells.

To obtain 1 m3 of material with average parameters, 320 kg of cement, 210 kg of sand, 110 l of water, 1.5 kg of foam concentrate, hardener (according to the instructions) are required.

Production of foam blocks, price and types of equipment

If you plan to make cellular blocks only for yourself, you can buy a small concrete mixer for 3,000 rubles, a foam generator with a compressor for 20,000 rubles. It is economically feasible for a small business to purchase a ready-made complex for the production of foam concrete and molds for blocks (you can even use it).
Foam concrete installations are equipped with everything necessary and occupy an area of 2.5 - 5 m2. Included in equipment, except necessary minimum, includes: a grate for loading sand and cement, a rotary pump, a vacuum gauge, a control cabinet, a water meter, hoses.
The PBU-300 foam concrete plant (average price 130,000 rubles) is very popular with the following technical data:

volume - 300 l:
weight - 380 kg
dimensions - 1.5 x 1.7 x 0.85 m
productivity - 0.9 m3 / hour;
power - 2.2 kW.

Forms for pouring foam blocks can be made by hand. But it is quite difficult to do this in a handicraft way: you need to strictly maintain their dimensions so that the manufactured blocks have the correct geometric parameters. An acceptable option is to buy used equipment. Its cost depends on the material and the total capacity. Estimated prices for molds for foam blocks are shown in table 2.

The price of the received foam blocks

Initial data. It is planned to build a house 8 x 10 x 2.5 m, for this you need (8 + 8 +10 + 10) x 2.5 x 0.2 \u003d 18 m3 + stock 2 m3 \u003d 20 m3 of foam block. It is planned to purchase a concrete mixer - 3,000 rubles, a foam generator with a compressor - 20,000 rubles, plywood molds - 6,000 rubles.
To determine the cost of a cellular block, add up the material costs for the manufacture of 1 m3 of the product and the cost of equipment, divided by the volume of cast blocks.

Materials per 1 m3 (cement, sand, water, foaming agent SDO-M) - 720 rubles.
Electricity (2.5 kW) - 11.25 rubles.
Unit costs for equipment: (3000 + 20000 + 6000): 20 = 1450 rubles.

The cost of a cubic meter \u003d 720 + 11.25 + 1450 \u003d 2181 rubles.
The purchase of cement at a wholesale price and the loading of equipment at the end of construction (for example, leasing) allows you to reduce the price indicator.

Production technology

The technological process consists of several stages.

The technology of cutting foam concrete is less popular. According to this method, the mixture is poured into a large mold, and after drying, cut into blocks of the desired size. At the same time, it is easier to achieve the correct geometry of products, even edges and corners - this reduces the cost of correcting deficiencies. However, the machine for cutting blocks with abrasive wheels is not cheap, and, in addition, it is difficult to determine the moment of cutting.
To make the production of foam blocks at home more profitable, it is recommended, after mastering the technology, to open a small business and produce foam concrete blocks for sale.