The production of gas blocks is currently quite profitable. The material belongs to the group of cellular concrete. This means that most of it is filled with gas bubbles, which significantly reduces their physical weight. Moreover, they have good thermal insulation characteristics and strength parameters. Thanks to the listed characteristics, gas blocks have become quite popular in a short time.
General information about gas blocks
If we talk about what constitutes aerated concrete or a gas block, then this is a stone of artificial origin, which is characterized by the presence of a large number of microscopic pores. This material is also often called autoclaved aerated concrete, which gives an idea of the technology for the production of gas blocks.
It is worth noting that building material is also characterized by a high rate of energy saving. This is explained by the presence of the same porous structure. Another good advantage is the low weight of each unit.
The production of gas blocks has also become widely popular because not only partitions for structures, but also load-bearing walls can be built from them. It will not be possible to use such cellular concrete in industrial construction or in the construction of high-rise buildings. The main scope of use is private construction. In this case, one more advantage can be distinguished, which consists in the fact that the blocks do not exert strong pressure on the foundation, since they weigh quite a bit. This helps to save significant funds on the arrangement of the foundation.
Materials for aerated concrete
All the advantages mentioned above appeared due to materials that serve as raw materials for the production of gas blocks. In fact, for the manufacture of the material all three components are necessary - this is cement, quartz sand and a gasifier, the role of which is played by aluminum powder. Although it can be said that some manufacturers still add additional elements to the composition, for example, lime or ash.
Aerated concrete manufacturing
The production of gas blocks is carried out from a group of dry materials that are mixed together with the addition of water. As the latter, you can use any water of a technical type that will be suitable according to the requirements of GOST 23732-79. When adding fluid, it is important to monitor its temperature. If it is hot enough (45 degrees Celsius), this will accelerate the solidification of the block, increase its maximum margin of safety. If we are talking about production on an industrial scale, it will also help increase productivity. Because of these reasons, almost all companies that have gas-block production plants heat water before adding it to dry ingredients. Another plus of using just a heated liquid is that you can save the amount of cement, since hot water stimulates the activity of dry raw materials more strongly.
The choice of sand for production
Mini-production of gas blocks or industrial requires careful selection of an ingredient such as sand. If we consider the issue from a theoretical point of view, then we can apply both quarry and river sand. There is one most important requirement, which is that this raw material should have a minimum of clay and clay impurities. A significant role is played by the size of sand grains - not more than 2 mm.
It is worth highlighting the production of an autoclaved gas block, since during its manufacture sand can be replaced with ingredients such as slag or ash. For example, if ash is used from thermal power plants, the density of the finished product will be reduced, which will reduce manufacturing costs.
Cement and blowing agent
In order to obtain a high-quality product in the production of aerated concrete blocks, foam concrete blocks and other cellular concrete, it is necessary to use such cement grades as M400 or M500. The best option is to choose the raw material that fully complies with its characteristics GOST 10178-85. As for the blowing agent, aluminum powder is usually chosen either from PAP-1 or PAP-2. In rare cases, not a powder, but a special paste is chosen as a blowing agent. It is worth noting that a suspension can also be used, since mixing dusty material is not always convenient.
The essence of the action of powder is as follows. Aluminum will react with cement or lime mortar, which has the properties of alkali. During the course of this process, elements such as calcium salts (aluminates) and gaseous hydrogen are formed. These two substances will form pores, making the structure appropriate.
In order to create a quality product, it is very important to choose the right proportions for each component. To date, there are general recommendations on the technology for the production of aerated concrete blocks: from 50 to 70% cement of the total mass, from 0.04 to 0.09% of the aluminum mixture, as well as from 20 to 40% of sand raw materials. Additionally, industrial water from 0.25 to 0.8% and lime from 1 to 5% will be required. In other words, for example, to get 1 cubic meter of a product, you must have: 90 kg of cement, water up to 300 l, 375 kg of sand and 35 kg of lime. The amount of aluminum powder is only 0.5 kg.
Although it is important to understand that these are just general recommendations for the composition. The number of components can be adjusted already at the factory, depending on the desired end result.
What is needed for production?
As for production technology, it is quite simple. However, despite this, dispensing with home methods or equipment will not work here. In this case, you will have to buy a special machine for the production of gas blocks, if it is necessary to produce cellular concrete for your own purposes.
However, it is worthwhile to understand that it will not be possible to purchase just one machine. The equipment enters the line of production of aerated concrete blocks comprehensively. This is a kind of mini-factory. When purchasing such equipment from the manufacturer, you can get the services of a specialist who will help to understand and establish the process, tell you how to choose the right components and their quantity.
Types of equipment
Fixtures for the manufacture are currently divided into several types. The main criterion for choosing one of them is the required productivity per day. It is also very important to understand how many people will serve such a line.
The first type of equipment is stationary. The daily productivity of such a line is 60 cubic meters. Most often, a warehouse or production room is used for its placement, the total area of which is at least 500 m 2 . The main feature is that the molds are moved to a stationary mixer, where they will be filled with solution. After that, all other technological stages of production are carried out. In order to successfully operate the line, only one additional worker is required.
Conveyor equipment
Conveyor lines are equipped where it is necessary to significantly increase productivity. This parameter of such a complex is 75-150 cubic meters per day. In this case, the production rate is faster, only the duration of the solidification of the blocks does not change, since it does not depend on the line. However, along with this, much more space will be required than for stationary equipment. In addition, at least 8 people are involved in the service, despite the fact that most of the procedures are automatic.
Small complexes
As for mini-lines for production, these are the most inefficient installations, only 15 cubic meters per day. They differ from stationary complexes in that not a form is promoted here, but a mixer. This allows you to greatly reduce the required amount of space to 140-160 m 2 . Most often, they are purchased as a starting option for a gas block production line.
There is another separate view called mobile installations. They are used only during private construction. It is worth noting that according to the calculations of specialists, such installations pay off quite quickly. In addition, they help to save construction costs by about 30%. The peculiarity of mobile installations is that they come with a compressor, and can work even when connected to a regular home electrical network.
Manufacturing steps
It is important to note here that aerated concrete can be autoclaved and non-autoclaved. The difference is that the second option is cheaper, but its strength indicators are less. However, due to the fact that the cost of production is much lower, it is widely popular. For this reason, it is worth considering the stages of material production.
- The first stage is, of course, the selection of all the necessary components in their exact dosage. After this, they must be thoroughly mixed to obtain a solution. If equipment is available, this procedure takes no more than 10 minutes.
- The second stage is that the previously prepared solution must be placed in special forms. Suitable equipment is used for this. It is worth knowing that you only need to fill out the form by half, as the mixture will increase over time due to the formation of gas bubbles. As for the time, the process takes 4 hours, during which the mixture usually fills out the form completely. It also happens that there is not enough space. In this case, the excess must be removed 2 hours after loading.
- The last stage is the exposure of the finished block. This procedure takes approximately 16 hours. After that, you can deal with the removal of material and its unloading on pallets. Next, you need to leave them on pallets so that they gain the so-called tempering strength. In time, this stage takes from 2 to 3 days. After this period, the blocks can be sent to the warehouse, however, they can only be sold on the 28th day, since only by this time the strength will reach the desired indicator.
Production for sale
In the end, it is worth adding that the production of aerated concrete blocks is a highly profitable business. This is clearly visible after comparing the cost and price. The cost of 1 cubic meter of finished products usually reaches 1800 rubles. As for the retail price per 1 cubic meter, it can reach 2500 rubles. As you can see, net profit from just one cubic meter reaches 700 rubles.