What is better - aerated concrete or foam block: a

When during construction there is a need for an inexpensive lightweight material that has good thermal insulation properties, the choice is usually between foam concrete and aerated concrete. But which one is better to prefer? To answer this question, you should first familiarize yourself with the features of each material, which we will do further.

General information

Foam concrete и газоблок относятся к одной группе материалов – легким или ячеистым бетонам. Они характеризуются наличием в своей структуре множества пузырьков (ячеек), заполненных воздухом, которые улучшают физико-механические свойства бетона.

Gas concrete и пенобетон отличаются по ряду параметров, включая:

• Composition;
• Physical and technical properties;
• Performance characteristics.

Production differences

Foam concrete

Foam concrete представляет собой смесь бетона и специальных добавок для образования пены. Пенообразователь для бетона может быть органического и синтетического происхождения. При производстве материала, смесь заливают в формы, в которых после затвердения получаются готовые блоки (узнайте здесь, как производится демонтаж бетона).

Foam concrete отвердевает и набирает прочность в естественных условиях. В некоторых случаях раствор заливают не в формы, а в опалубку. В этом случае образуется монолитный пенобетон.

Thus, the difference of foam concrete from the foam block in the first place is that it can be made not only in the factory, but also on the construction site.

Instructions for making the material is quite simple. The main thing - to observe certain proportions when mixing components.

Gas concrete

The difference between aerated concrete blocks and foam blocks is that they do not add a chemical foaming agent to their composition. Therefore, the material consists entirely of mineral raw materials.

It consists of the following components:

• Sand;
• Cement;
• Lime;
• Gypsum;
• Water;
• Aluminum paste or powder (as a blowing agent);

Cells in this material are formed as a result of a chemical reaction between aluminum powder and alkali, as a result of which hydrogen is released.

After pre-curing, the material is cut with special strings into separate blocks, which provides them with perfect geometry. As a result, when laying concrete blocks, the minimum thickness of the seams is obtained, which prevents the formation of cold bridges.

According to the method of hardening, aerated concrete is divided into two types:

• Autoclave - hardens at high pressure in an environment of saturated steam.
• Non-autoclaved aerated concrete - hardening occurs in natural conditions or in an environment of saturated steam, but at atmospheric pressure.

Autoclave газобетон набирает окончательную прочность в специальной печи – автоклаве, под воздействием пара, большого давления и высокой температуры. В процессе автоклавирования практически все компоненты вступают в реакцию, благодаря чему материал образует совершенно новую кристаллическую решетку, идентичную природным минералам, таким как гидросиликаткальция или тоберморит.

This material is made on large-scale production, so it enters the construction site in the form of finished blocks. It is impossible to manufacture autoclaved aerated concrete blocks with your own hands in artisanal conditions, since in the process of their formation it is necessary to simultaneously control several dozen parameters and processes.

Modern plants for the production of autoclaved aerated concrete have a high degree of automation (up to 95 percent). Therefore, the influence of the human factor on the production process is almost completely excluded.

Обратите внимание! Autoclave газобетон изготавливается по ГОСТу, соответствие которому проверяется определенными испытаниями. Поэтому, при покупке материала, необходимо проверить наличие сертификата качества.

As for non-autoclaved aerated concrete, its characteristics and operational properties are somewhat inferior to autoclave. However, manufacturers are constantly improving its quality by improving the composition and use of steam processing in the formation of blocks. In addition, it should be noted that the price of non-autoclaved material is lower than autoclaved material.

Material comparison

Strength

Foam concrete и газобетон бывают разной плотности - от 300 до 1200 кг/м3. При этом пенобетон существенно проигрывает прочности и физическим свойствам автоклавному газобетону. Однако, все проекты домов из пеноблоков и пенобетона подразумевают возведение небольших легких строений, так как прочности материалов недостаточно для строительства тяжелых многоэтажных домов.

It must be said that the indicator of the strength of foam concrete depends on the quality of the foaming agent. Given the desire of manufacturers to save on the manufacture of blocks, most often they use a cheap component, resulting in unstable strength indicators, i.e. may differ in different parts of the block. Aerated concrete is absolutely homogeneous material with the same strength throughout the array.

Shrinkage

When laying walls of foam concrete, the risk of cracking is much higher, which is associated with a high rate of shrinkage. However, this disadvantage is present in non-autoclaved gas blocks. Therefore, the degree of shrinkage of the autoclaved material is significantly lower and does not exceed 3 mm / m.

Tip! A high degree of shrinkage is not so critical if monolithic foam concrete is used, i.e. embedded in the formwork.

Environmental friendliness

Gas concrete является абсолютно экологичным и паропроницаемым материалом. Поэтому в домах, построенных из газобетона, образуется благоприятный для человеческого организма  микроклимат, схожий с микроклиматом в деревянных домах. Благодаря способности регулирования влажности в помещении, исключается вероятность образования на стенах грибка и плесени.

In the manufacture of foam used chemical foaming agents, it reduces the level of environmental friendliness of the material. In addition, the foam contains in its structure closed air bubbles, with the result that it is more tight and not able to pass the steam.

Geometry

The accuracy of the dimensions of the autoclave gas blocks is governed by GOST, according to which deviations from the dimensions should not exceed 1-3 mm. In the manufacture of foam blocks, deviations from the size can reach 5 mm.

Violations of the geometry of the foam blocks are related to the manufacturing technology — it is impossible to provide accurate geometry during mold casting, as in the case of cutting the material with strings.

Water absorption

The level of hygroscopicity of the foam block is slightly higher than that of gas blocks, however, the difference is insignificant. Water does not penetrate deep into the aerated concrete, as part of the pores of the material also have a closed structure.

Thermal insulation properties

Thermal insulation properties материалов, будь то газобетон или пеноблок, напрямую зависят от уровня плотности. В целом, показатели практически идентичны.

However, given that the strength of aerated concrete is higher, a less dense material may be used in construction. Accordingly, the level of insulation of the walls of the gas blocks can be better.

Simple treatments

The advantage of all types of cellular concrete is the simplicity of their processing. Cutting blocks can be a regular hacksaw, while for other materials use a more powerful tool. For example, it is allowed to cut reinforced concrete with diamond circles, which is performed using a grinder and takes quite a lot of time.

You can drill a hole in a cellular concrete using a conventional drill, and for reinforced concrete a perforator is used with a blow or diamond drilling of holes in the concrete is performed.

Claydite as an alternative to foam block

It must be said that there is still such light material on the market as expanded clay concrete. Therefore, developers are often interested in what is better - foam blocks or expanded clay concrete blocks? If you briefly describe the expanded clay concrete, then we can say that it is more durable, but it has a lower degree of thermal insulation.

Therefore, choosing which material to use - claydite-concrete blocks or foam blocks, you should decide that it is more important - thermal insulation or strength.

Summing up the comparison of materials, we can distinguish the following points:

• Foam concrete и газобетон являются разновидностью пористого бетона.
• Autoclave aerocrete surpass foam concrete physico-technical properties. In particular, they have greater strength with less weight. True, this does not apply to non-autoclaved aerated concrete.
• Gas concrete является паропроницаемым материалом, благодаря чему стены обладают способностью «дышать», в то время как пеноблок препятствует естественному влагообмену в помещении.
• Autoclave gas blocks have more accurate dimensions and uniform density.
• When building a wall of foam concrete, there is more likelihood of cracking.

Conclusion

Based on the above material, it can be concluded that aerated concrete, especially autoclaved, is a more advanced material than foam concrete. We recommend to get acquainted with additional information on this topic from the video in this article (learn also how to make a drainage well from concrete rings).