As practice shows, the construction of partitions and load-bearing walls takes almost 50% of the building materials needed to build the entire building. To reduce construction costs, consumers choose materials with similar performance characteristics but at a lower cost. Among such materials are gas silicate blocks.
Knowing the properties of these products, their disadvantages and advantages will help to avoid mistakes that can affect the quality of a residential building and its durability.
Product Features
Low cost is the main advantage of gas silicate blocks, a square meter of them costs two times cheaper than when using bricks. The ability to manufacture products of complex shape is also very important, due to which the speed of building construction increases significantly.
Gas silicate is a subspecies of cellular concrete. For its manufacture, an industrial autoclave is used, but it is also possible to manufacture products at home. The following components serve as raw materials:
- Portland cement.
- Aluminum powder.
- Silica aggregate.
- Water.
Catalyst - quicklime, it reacts with aluminum and foams the mixture. As a result, hydrogen is released, forming tiny bubbles. In production in an autoclave, after mixing, the mass is steamed and poured into a mold. After hardening, the plate is cut into elements of the desired size and shape.
Types of block structures
Products by density are divided into several subspecies:
- Gas silicate blocks with compressive strength D700. This material is the best option for the construction of multi-storey buildings, both industrial and residential. In low-rise construction, it is used for the construction of load-bearing walls and partitions.
- Products with strength characteristics D500-D600. They are used in the construction of low-rise (maximum - three floors) structures. In areas with a warm climate, such buildings do not need insulation.
- Heat-insulating products. The strength of the plates of this brand is D400. They are used for insulation of built or newly built objects or for the construction of non-load-bearing partitions.
- Blocks below 400 kg/cu. m. The distribution of such structures is very limited. They can only be used as a heat-insulating material, for example, for heating networks. Due to their low density, the boards do not let heat and cold through at all, therefore they represent the most effective example of thermal insulation.
Note:regardless of the strength of the products, they are used in the construction of multi-storey buildings and industrial facilities only as a heater.
Material specifications
The main specifications are as follows:
- Specific heat capacity. The indicator is measured in kJ / kg° С. For gas silicate, it is equal to one, while for reinforced concrete structures it corresponds to 0.84.
- Thermal conductivity. The density of gas silicate (0.14 W / m° C) is similar to the density of spruce or pine wood, therefore, it conducts heat just as poorly as materials from the wood of these species. For comparison, the density of reinforced concrete is 2.04, so buildings made of this material are hot in summer and cold in winter.
- Sound absorption. Due to the presence of voids inside the blocks, the sound is poorly transmitted.
- Cyclical frost resistance. Depends on the density of the material - the higher it is, the more freeze / thaw cycles the building withstands. So, blocks with a density index above 600 can withstand up to 50 cycles, that is, years. If they are protected from wind and moisture, the service life can be increased by 50%.
Product weight
For building a house, it is very important to know the weight of the products in order to choose a reliable foundation option. Although gas silicate weighs less than brick and stone, it also has its own weight. This parameter depends primarily on the brand of products. For example, a cube of D300 brand gas silicate blocks weighs 300 kg, D500 brand - half a ton, D800 brand - 0.8 tons. The weight of an individual block depends not only on the brand of aerated concrete, but also on its dimensions.
To calculate the mass of one block, the weight of a cubic meter is divided by the number of elements in it. So, for example, a cube of block structures measuring 25x40x60 cm weighs 500 kg and consists of 16 elements. It is easy to calculate that 500:16=31.25 kg. Products of similar dimensions of brand 400 weigh 25 kg, brand 600 - 37.5 kg.
How do I calculate?
Finding out how many gas silicate blocks are needed to build a building of a certain size is not difficult at all - the dimensions of the products are adjusted to the standards of building materials, in particular brick. The thickness of the solution layer was also taken into account. To find out the exact number of blocks needed for operation, you should calculate the volume of one block, clarify the number of elements that are needed for laying 1 sq. m and then calculate the total.
In the prepared project, the dimensions of all partitions and walls must be indicated. By multiplying their total length by the desired height, the desired result is obtained. Just do not forget that from the resulting figure it is necessary to subtract the area of \u200b\u200bwindows and doors. Further, 10-15% is added to the result. This is a calculation for a fight, chips, other defects that may appear during transportation and installation.
Material Values
The following characteristics of blocks can be called advantages:
- Light weight, so you won't need to build a reinforced foundation, likefor brick walls - you can build a columnar structure or a shallow foundation of a tape type.
- Poor thermal conductivity. A house made of gas silicate blocks holds heat 5 times better than a brick building of the same type.
- The ability to build structures of complex and unusual geometric shapes. Moreover, this can be done without much effort, while when working with a brick, it will be necessary to spend a lot of time giving the individual elements the desired shape.
- High vapor permeability. At high humidity, gas silicate absorbs moisture, and when the air becomes too dry, it gives it away. Thanks to this, a cozy and comfortable microclimate for a person is created in the house.
- Fire safety. Gas silicate belongs to low-combustible materials of group G1.
- Ability to do construction work at any time. Today, there is an adhesive for gas silicate blocks on sale, with which you can work even in winter.
An important detail: there is one caveat - it is unacceptable to work in rain or snow, since moisture, getting into the pores, collects in them and begins to destroy the structure from the inside.
Flaws. What are the disadvantages of gas silicate products?
Although today projects from gas silicate blocks are a profitable, justified and modern solution, this material does not take a leading place in terms of demand. The reason for this is its shortcomings:
- High water absorption properties. Having accumulated moisture, the structures lose their strength, so the buildings must be protected from water ingress orsnow. Moreover, in a humid environment, a fungus quickly appears, which will be impossible to remove from the porous structure of the material.
- Shrinkage in the first year after laying the walls. Because of this, finishing work has to be postponed.
- Low mechanical strength. If brick walls were able to withstand even the siege of troops in the Middle Ages, gas silicate blocks can easily crumble with mild blows. Because of this, when furnishing a home, the nails under all the shelves must be fixed in the wall with glue so that they do not slip out.
- Inadmissibility of using sand-cement plaster. A gypsum mixture is used instead.
Structure sizes
The standard size of manufactured structures is 60x30x20 cm. Blocks of such dimensions are considered optimal for the construction of low-rise buildings. But these sizes specified in GOST 21520-89 are not mandatory, so manufacturers can produce products of other sizes that exceed those indicated in length and height.
In addition, products are produced in different types, the sizes of which differ from the standard. This is:
- Direct blocks. Sizes 20x25x62.5 cm, 30x25x62.5 cm or 20x30x62.5 cm.
- Products equipped with tongue-and-groove system and grip handles. Dimensions 37.5/40x25x62.5 cm.
- Pazogrebnevye designs. Sizes 30/37, 5/40х25х62, 5 cm.
- Products for partitions. Dimensions 15/10x25x62.5 cm.
- Designs for U-type jumpers. Dimensions 20/30/40x25x50 cm.
Cost
Like the mass of products, their cost varies by brand.
| Size cm | Brand | Quantity in cubic meters | Weight of one element, kg | Price per cube |
| 20х30х62 | D 500 | 26, 7 | 24, 0 | 2, 9 thousand rubles |
| 20х30х62 | D 600 | 26, 7 | 29, 0 | 3, 0 thousand rubles. |
| 25x40x60 | D 500 | 16, 7 | 39, 6 | 3,05 thousand rubles |
| 20x25x60 | D 600 | 33, 4 | 24, 0 | 3, 15 thousand rubles |
| 10x25x60 | D 500 | 66, 7 | 9, 9 | 3, 15 thousand rubles |
Based on the above parameters, you can calculate the price of gas silicate blocks per piece. For example, if there are 33 pieces in a cubic meter with a total cost of 3,150 rubles, then one element will cost about 97 rubles.
