We evaluate the quality of aerated concrete
Aerated concrete is a cellular concrete or artificial stone with closed spherical pores with a diameter of 1-3 mm. Aerated concrete is produced from cement, quartz sand or industrial wastes of ash and slag, lime with the addition of a gas generator in the form of aluminum powder.
In the dry mixture, when water is poured, a chemical reaction occurs between the lime and the aluminum powder with hydrogen evolution. The mixture thus increases in size similar to the test. After the beginning of hardening, the mass can be cut into blocks, slabs or panels. Then the final hardening takes place. It turns out the material, which eventually becomes harder, can be easily processed and does not burn.
To build a house made of aerated concrete, you need to know the advantages and disadvantages of this building material. Advantages are more than drawbacks, and they are:
- manufacturability - the block is easily cut with a hacksaw;
- light weight - the block weighs about 36 kg, and 15 bricks - 52 kg. Masonry is carried out on a special adhesive mixture, which is much lighter than cement mortar;
- exact dimensions and a flat surface - do not apply plaster, you can simply sand;
- excellent heat and sound insulation. The air in the voids will be the best insulation.
Disadvantages have been little studied, because the material is used relatively recently. These include the formation of cracks along the blocks, high water absorption, brittleness and poor retention of dowels.
Preparing for the construction of
Aerated concrete is gaining popularity, and if we build a house of aerated concrete, then this is not an exclusive, but a pervasive practice. Construction can be carried out at a temperature of +5 to +25 ° C, if the air has warmed up, ready aerated concrete should be constantly moistened with water.
Aerated concrete can not easily be made by hand. On the ground you need to lay a roofing felt, put molds on the right size, wipe the walls of the mold from inside with cleaning. Cover the dry mixture, mix well and gradually pour in water, continuing to mix. When the mixture "rises" and slightly hardens, the mold needs to be removed and the blocks left in place.
After 12 hours your attempts to make gas blocks with your own hands will be crowned with success, ready bricks should be transferred to the canopy and let stand for at least a day. After that you can stack them. Calculation of aerated concrete blocks is made from such a consideration that 1 block replaces 14-15 bricks. For work it is necessary to prepare tools:
- jugs and carriage for applying glue;
- saw with hard-alloy teeth;
- rubber hammer;
- shtoborez;
- square for cutting at right angles;
- grater with metal teeth;
- coarse-grained sandpaper.
Making a house made of aerated concrete
Building a house from a gas block needs to begin with consultation with the local geodetic service. Specialists will determine the level of groundwater and freezing. Aerated concrete absorbs moisture, and good waterproofing is needed. What kind of foundation is needed, tell the surveyors, but on top of the foundation must be laid a layer of waterproofing overlap. It is necessary to arrange a blind area to prevent unnecessary moisture absorption.
On top of the waterproofing, apply a thin layer of cement for leveling, and then lay the made aerated concrete blocks with your own hands. The first row is of particular importance, it sets the right packing for all walls. It should be laid perfectly smoothly, it should be checked by level or laser device.
When the first row reaches the corner, it is necessary to cut out precisely the size of the remaining distance of the additional block, smear the end surfaces with glue and adjust the position of the entire structure with a rubber hammer.
After laying each row of blocks, the entire surface must be leveled with a grater with metal teeth to remove the slightest level changes. If this is not done, a stress concentration is formed in the masonry, and vertical cracks appear in these places.
The laying of aerated concrete blocks is carried out so that the level and evenness are observed in all rows as accurately as possible. It's easy - everything is cut and cut very simply. It is important that the blocks are adjusted as much as possible, since the gas-block cladding is carried out with minimal use of the adhesive solution.
In places of adhesive joints heat loss is higher than on the surface of aerated concrete, and these places are trying to make as thin as possible. Window and door openings need to be covered with reinforced elements, by the way, there are ready jumpers on sale. The laying of aerated concrete blocks in combination with bridges gives the structure greater durability. Walls made of aerated concrete blocks are completed with prefabricated-monolithic overlap of cellular concrete or light reinforced slabs.