What is the difference between aerated concrete or foam concrete - a comparison of the advantages and disadvantages
Before you build a house, you need to decide what to build it from. It is the chosen material that determines how strong and comfortable the home will turn out. Good walls and heat will not be allowed outside, and outside noise will not be allowed into the rooms. And they must be environmentally friendly and fireproof. Now at the peak of popularity, light and durable cellular materials for walls. Often, the developer for a long time ponders what to buy: aerated concrete or foam concrete - what is the difference between them. At first glance, it does not exist at all. Let’s take a closer look.
Content:
We understand the terminology
Cellular concrete is called lightweight cement-based materials. Their feature is the presence of numerous cells, so that the material acquires many useful properties - both physical and mechanical. Aerated concrete has several varieties. In addition to the above-mentioned foam concrete and aerated concrete, there is, for example, gas and ash concrete. Porous concrete can be autoclaved and non-autoclaved.
By the method of formation of these cells, materials such as:
- Aerated concrete;
- Foam concrete;
- Foam concrete.
According to the method of solidification, porous concretes are divided into:
- The autoclave method involves hardening the material at elevated pressure in a sealed tank into which saturated water vapor is added.
- The non-autoclave method assumes that the material hardens in a natural environment. At the same time, it warms up with the help of electricity. Processing of concrete with saturated steam is also possible. But, unlike the previous method, the pressure does not increase.
Foam concrete and aerated concrete are quite significantly different from each other. They have different composition and characteristics. And in operation, both materials manifest themselves very differently.
Features of the production of foam blocks and gas blocks
1. To make foam concrete, mix the cement base with special additives. They are necessary for foaming the mass. These foaming agents are both based on synthetic substances, and organic. The foamed mass gets into special forms, where it hardens in the natural environment. The result is foam concrete blocks. The material, called monolithic, is poured not into forms, but into the formwork. After solidification, the removable formwork is disassembled. Fixed formwork remains in place.
The structure of foam concrete.
2. There is a significant difference between foam concrete and aerated concrete. The latter, unlike foam concrete, can only be manufactured under production conditions. In order for it to foam, no special chemical additives are needed. Aerated concrete consists of natural substances - water, cement, lime and gypsum. Also, a certain amount of aluminum is added to it - in the form of powder or paste. It is this substance that promotes gas formation.
Aerated concrete is made in a special container - an autoclave. To give the material strength, it is exposed to high pressure and temperature, as well as water vapor. In the production process, a chemical reaction between the components occurs, and a substance with new properties is formed. And its crystal lattice is similar to the lattice of some organic substances. These are, for example, calcium silicates, in particular, tobermorite. The chemical reaction is accompanied by the release of hydrogen - it is this gas that makes the material porous and fills these very pores.
The structure of aerated concrete.
When aerated concrete finally hardens, it's time to cut it into neat, identical blocks.To do this, strings are used that provide an almost perfect even cut. Due to this, when laying blocks of aerated concrete, the seams are very thin. So the bridges of cold, through which a lot of heat can go into the street, can be avoided.
Video: Production and differences of aerated concrete from foam concrete
Compare the characteristics of foam concrete and aerated concrete
GOSTs for the manufacture of both the one and the other material are the same. Deviations from them are not allowed. It would seem that the characteristics of both porous concrete should coincide. In fact, differences exist.
Moisture absorption and frost resistance
The difference in manufacturing techniques affects these two parameters. So, aerated concrete absorbs water like a sponge. Because of this, during frosts, he manifests himself not in the best way. In foam concrete, water absorption is much lower. But it should be remembered that usually walls made of cellular materials do not leave “as is” - they are covered with a protective layer. It can be plaster, siding or tile cladding. So in practice, you can not take into account the difference in water absorption. But you can know that aerated concrete is losing here.
Video: Aerated concrete drowning or floating
What is stronger
The density of both porous concrete can vary from 300 to 1200 kilograms per cubic meter. If we compare aerated concrete and foam concrete of the same density, it turns out that the latter is less reliable and strong. In addition, the strength of this material directly depends on the quality of the foaming agents. Since a good foaming agent has a high price, some manufacturers trick and replace it with a cheaper one. The strength of foam concrete is unstable over the entire surface of the block. But the aerated concrete block is homogeneous and equally manifests itself at all points.
Environmental Safety
During the production of autoclaved aerated concrete, a reaction occurs between lime and aluminum. The hydrogen released as a result is far from being released during the solidification of the material. Part of this gas (however, quite a bit) can escape during construction, and then, when the walls of the house are already folded. But hydrogen is not a poisonous gas, so it does not produce a poisonous effect on the human body. Foaming agents, both protein and artificial, also contain no harmful substances. In addition, the pores of the foam concrete are closed and tight. It turns out that both of these materials do not have significant environmental disadvantages, and this parameter cannot be decisive in the choice of this or that material.
Video: Is it true that aerated concrete is poisonous and banned in Europe
Which material is more prone to shrinkage
Cracks may occur in a wall lined with foam concrete blocks. After all, the shrinkage rate for this material is from 1 to 3 mm / m. Aerated concrete blocks practically do not crack, since the same parameter for them is no more than 0.5 mm / m.
Heat holding ability
The denser the structure of aerated concrete is, the worse its thermal insulation ability. Therefore, foam concrete with a low density is a better heat insulator than aerated concrete. But the bearing walls cannot be laid out of it - it is not strong enough. Therefore, it is necessary to use a denser material, but make the walls thicker, because its thermal conductivity is higher. For example, for Novosibirsk, the walls of a house made of foam concrete blocks D600 should be no thinner than 65 centimeters. Then the house will be warm enough.
If, under the same conditions, walls of aerated concrete are laid, then they will turn out no thicker than 45 or 50 centimeters. And the density in this case will be sufficient D 400 or D 500. As you can see, aerated concrete is much better able to retain heat, and the wall from it turns out easier and stronger. However, aerated concrete or foam concrete to use for your home, you decide.
Fire resistance
Both materials perform well in this regard. And also these cellular concrete pass the air well, and also contain only substances of natural origin. They are lightweight and easy to operate.With regard to resistance to frost, aerated concrete in this regard is twice as reliable, and sometimes triple.
Compare cost
Foam concrete is significantly cheaper - about 20 percent. After all, the components for its manufacture are not very expensive, and the equipment is not complicated. But during construction it may be needed more than aerated concrete. Therefore, you should not look only at the price of a cubic meter of material - first calculate the entire project of the future home.
It is also important that aerated concrete is laid on the adhesive mixture, and for foam blocks and an inexpensive cement mortar is quite suitable. True, with glue laying is faster, and it will need much less than a cement mixture. As a result, it turns out that the cost of laying foam blocks (including all materials) exceeds the cost of laying gas blocks. In addition, a thin layer of glue, unlike cement, does not provide cold bridges. As a result, the house is more energy efficient.
Compare sizes
Since blocks of aerated concrete are manufactured in the factory, their dimensions are more stable than that of foam blocks. Indeed, foam concrete can be made directly at the construction site - using special installations. As a result, both the consumption of materials for laying and the convenience of the masonry are different for both cellular concrete. But this does not mean that aerated concrete is the winner in all respects.
We hope that this comparison of the advantages and disadvantages of foam concrete or aerated concrete was timely and provided you with assistance. Good luck in the construction!
Video: Which is better? Aerated concrete or foam concrete?
