The technology of the production of the aerated concrete
The cellular concrete is comparatively new material: if the brick is more than 300 years old, the cellular concrete is not more than 100 years old. It is an artificial porous stone, which can swim in the water. It corresponds to all requirements of the normative documents applied to the construction materials in solidity, deformability, frost-resistance. Its heat-shielding qualities are 3-12 times higher than the brick has. A wall made of this material can "breathe" providing good microclimate in the room. But the cellular concrete unlike the timber having just the same qualities is notable for its fire and biological stability.
Non-autoclave aerated concrete as a type of the cellular concrete having all the merits of the latter has some advantages. The aerated concrete has high water resistance, atmosphere resistance and low water absorbing. The solidity of the non-autoclave aerated concrete increases during its whole service life.
The method of aeration
Company "Astika" uses a method of preparation of the aerated concrete mixture, which avoids the production of the foam generator in the technological scheme, and allows to get aerated concrete of any density in the range of 250-1500 kg/m3 on one equipment using unmodified standard raw components.
This method consists in COMBINATION of the functions of the foam generator and the mixer with the help of one device, in which the process of mixing and the process of poring of the cement-sand mortar with frother admixture go simultaneously. The production of the aerated concrete of very high quality is achieved by special construction of the working organ of mixer and by turbulent-cavitation regime of mixing.
The supply of water and frother without preliminary getting of the foam to the mixer simplifies the technology of the preparation of the aerated concrete mixture and shortens the time of the technological cycle in favour of the aerated concrete.
The mixing of the raw components in the turbulent-cavitation regime allows getting aerated concrete of low density, minimizing power inputs and time for the preparation of the aerated concrete mixture.
The creation of the turbulent-cavitation regime in the mixer is provided by the performance of the working organ in the form of rotor-impeller, set on the shaft, with vanes provided with nozzles. The intensive dispersion of the aerated concrete mixture is provided by the vanes of the rotor-impeller, revolving on the shaft. The air, incoming into the dispersion of the cement-sand mixture, is broken by the vanes of the working organ into the small bubbles less than 1-2mm in diameter. Simultaneously with this process there is the process of condensation (cavitation) pore-formation: revolving, the nozzles leave the trace of large cavitation cavities, which are also broken into the small bubbles by the vanes of the rotor-impeller.
The carring out of the process of the mixing under the pressure 0,05-0,2 MPa during 0,5-3 min allows to get the aerated concrete of small density (from 150 kg/m3 and higher), of homogeneous structure, without the exfoliation of the aerated concrete mixture at height.