Aerated concrete blocks: types, characteristics, pros and cons

Aerated concrete is made from quartz sand and cement using gas generation technology. The result is an artificial stone with a porous structure. The presence of air-filled internal cells gives this building material high energy-saving, thermal insulation and lightweight properties.

Contents of the article:

• Material classification
• Main characteristics of aerated concrete blocks
• Pros and cons of aerated concrete blocks

what are the advantages and disadvantages of aerated concrete blocks?

Material classification

Aerated concrete blocks are of the following types

By type of main binder:

• Calcareous. Such blocks consist of 50% boiled lime. They may also contain gypsum, slag or cement;
• Cement. Up to half the mass of such aerated concrete blocks comes from Portland cement;
• Slag. This material includes a mixture (> 50%) of slag and gypsum, lime or alkali;
• Ash. This type of block is made from very simple ash. This component in its composition is more than 50%;
• Mixture. They are made from slag and lime (or a mixture of them) with the addition of 15-50% Portland cement.

Silica elements by type:

• Natural sand. As a rule, quartz sand is used to produce this type of aerated concrete blocks;
• Use of recycled materials. For this option, waste from the ferroalloy industry and fly ash from thermal power plants are used.

In accordance with the hardening conditions of secondary raw materials:

• Autoclave. This type of aerated concrete blocks is cured in an autoclave oven under high pressure and saturated steam;
• Non-autoclave. In this case, the material hardens in a humid environment, but using atmospheric pressure or electrical heating systems.

Main characteristics of aerated concrete blocks

1. The strength of this material is 10-12 kgf/sq. cm (for non-autoclaved aerated concrete) up to 28-40 kgf/sq. cm (for autoclave-type blocks). High pressure processing ensures maximum strength of the material.
2. Volumetric weight from 200 kg/cu. m. m up to 600 kg/cu. m. m. The lightest aerated concrete is used as thermal insulation. Heavier ones are used in low-layer structures.
3. The thermal conductivity of the blocks depends on the density and averages 0. 12 W/mdegrees. This is the optimal indicator in accordance with the latest requirements for heat transfer resistance in structures.
4. The frost resistance of aerated concrete blocks is F 100. For comparison, for M50 ceramic bricks this indicator corresponds to the F25 level, and for D500 aerated silicate blocks – F35.
5. Sound permeability. This property of aerated concrete blocks is determined by the density of the material, which averages 50 dB.
6. Shrinkage of autoclaved aerated concrete blocks is 0. 2-0. 5 mm/m. For non-autoclave materials that produce crumbs, this parameter is slightly higher – 2-5 mm/m.
7. The absorption is very high, approximately 20%. For brick this coefficient is 1. 5-2 times lower. Therefore, walls made of aerated blocks must be lined.
8. Fire resistance – up to 7 hours. Breathable concrete blocks are made of minerals that will not burn or melt.

Pros and cons of aerated concrete blocks

The list of main advantages of this building material includes:

• Aerated blocks are three to five times lighter than sand-lime brick. Houses made from such blocks are built on average 20% faster than brick buildings of the same size;
• Porous aerated concrete completely retains heat inside the building. The thermal conductivity of aerated blocks is two to three times higher than that of conventional bricks;
• This material can be easily sawed, drilled and made rigid without the use of special tools;
• Another advantage of the aerated concrete block is its high fire resistance. This material does not burn and does not emit hazardous gases when exposed to fire;
• Due to its porous structure, breathable concrete allows air to pass through well. Walls made of this material “breathe”, and a comfortable microclimate is created in the house;
• In terms of environmental friendliness, aerated concrete is second only to wood.

Among the disadvantages of this material are the following:

• Moisture absorption. Breathable concrete absorbs moisture well;
• Shrinkage. Irregular blocks give especially strong shrinkage;
• Insufficient strength. Houses with a height of less than three floors are built from this material.

Considering all of the above characteristics of permeable concrete blocks, we can say with confidence that this is the best material for low-rise construction in any region of Russia Buy Aerobel in Belgorod you can contact the BelSnab company.