Aerated concrete or foam block: comparing competing building materials

Aerated concrete and foam blocks are frequently mentioned as the best options when it comes to selecting the materials for your next construction project. Both are well-liked for being lightweight and having good insulation, but they have unique qualities that may make one more suitable for your purposes than the other.

The ingredients for aerated concrete, sometimes referred to as autoclaved aerated concrete (AAC), are cement, lime, water, and a tiny bit of aluminum powder. Its lightweight structure comes from the tiny air bubbles created by this mixture. It is renowned for being very user-friendly, fire resistant, and thermally insulated. Conversely, foam blocks are usually created by combining foam agents with cement. As a result, the material is not only lightweight but also easily shaped and cut, and it provides good sound insulation.

The needs of the particular project will often determine which of these two materials is best. Because of its well-known longevity and energy efficiency, aerated concrete is a great choice for structures where fire safety and insulation are essential. Although foam blocks are lightweight and insulating as well, their flexibility in design and ease of handling may make them the preferred option. You can make an informed choice that fits your budget and building requirements by being aware of the subtle differences between each.

The concept of foam block

The primary characteristics of a foam concrete block are its porous structure and unique way of forming during the manufacturing process. This occurs as a result of incorporating a foaming agent into the mixture, which causes the mixture to swell.

Let us examine the properties that this material possesses at its output.

Main properties and qualities

It is worthwhile to examine the primary set of characteristics of the material that point to the viability and longevity of the future structure in order to perform a thorough comparison. Here is a list of foam concrete’s mechanical, technical, and physical characteristics:

Name	Value
Frost resistance	From 35 to 80 cycles
Thermal conductivity in a dry state	From 0.09 for thermal insulation foam concrete to 0.38 – for structural
Strength kg / cm2	15-25
Density grade	400-1200
Water absorption	10-16% by weight

We will now use the table to analyze the operational and practical characteristics as well.

Additional features of foam concrete include:

Characteristic name	Value
Shrinkage	From 0.5 mm/m2
Price category of the material	The material is one of the most inexpensive
Construction speed	Quite high
Sound insulation	Average level
Vapor permeability	Capable of vapor permeability
Environmental friendliness index	2
Fire resistance	Does not burn

All of the aforementioned indicators, or more accurately, their values, are generally more than adequate to satisfy the fundamental needs of the majority of developers. Still, it’s too soon to make judgments.

Classification and scope of application

According to GOST, foam concrete is divided into multiple categories based on the composition, production variability, and other attributes of the product.

Depending on the density of the material, foam concrete can be:

• Heat-insulating. It has a minimum density, which varies within the range of up to D500. Such foam concrete is used as insulation, since it cannot withstand any significant loads;
• Structural and heat-insulating. Its strength is much higher: 500-900. It is used in the construction of walls and partitions;
• Structural foam concrete – the most durable, the indicator is equal to a numerical value from 1000 to 1200. It is used in the construction of buildings several stories high. It can withstand quite significant loads.

Additionally, structural-porous foam concrete can be distinguished. It has a density of up to D1600. GOST does not control this kind of content. It can only be produced in response to specific orders.

Apart from the aforementioned domains of utilization, foam concrete finds use in:

• When filling the frame of reinforced concrete structures;
• Monolithic foam concrete is used in the construction of screeds:
• When constructing structures using formwork;
• When insulating the roof, and in many other cases.

Depending on the accuracy category of the products, foam concrete is divided. Think about making use of the table.

According to GOST 21520-89, the accuracy categories of foam concrete blocks are as follows:

Deviation name	Blocks of accuracy category 1	Blocks of accuracy category 2	Blocks of accuracy category 3
By thickness and length	No more than 1 mm	No more than 3 mm	No more than 5 mm
By height	No more than 2 mm	No more than 4 mm	No more than 6 mm
Diagonally	2 mm	4 mm	6 mm
Facies and edges	1 mm	3 mm	5 mm
Broken corners (no more than 2 on one product)	Up to 5 mm	Up to 10 mm	Up to 15 mm

Furthermore, in compliance with GOST 25484-89, the content is separated into:

• Products of autoclave or synthetic hardening method;
• Products of non-autoclaved or hydration hardening method.

In the first scenario, the blocks are processed in special autoclave machines at high temperatures and pressures. In the absence of an autoclave, foam concrete solidifies naturally. There is no temperature increase above 100 degrees.

The final products differ in terms of appearance, block geometry, and quality attributes. It is also important to keep in mind that the proportions of raw materials used in handicrafts and home production may vary, which will surely cause a shift in technical indicators.

Products can vary depending on the kind of siliceous component used.

• On sand, most often quartz;
• On ash;
• On other secondary industrial products.

Depending on the primary binder type, the material can be:

• On cement;
• On sand;
• On ash;
• On slag;
• On a mixed binder.

In this instance, the main component’s concentration relative to the total mass ranges from 15 to 50%. It is important to note that some producers of foam concrete blocks give them a facing side. They don’t require any further external finishing.

Strengths and weaknesses of the material

To help get rid of unwanted features of the future structure, it is vital to weigh all the benefits and drawbacks of the materials when comparing foam block and aerated concrete.

Among foam concrete’s benefits are:

1. The lightness of the material eliminates a large load on the foundation;
2. Ease of processing partly guarantees high construction speed;
3. Foam concrete is made from a mixture of sand, cement, water and foaming agent. These components do not have a harmful effect on the environment and humans, which means that the products are environmentally friendly. The numerical indicator of environmental friendliness is 2-um, which is only 1 point higher than that of wood.
4. Fire resistance is another significant plus. Foam concrete does not support fire.
5. Price. The products are among the most inexpensive. And if you compare them with the cost of brick, then the construction costs when using this material will be about 15% less.
6. Foam concrete is quite durable.
7. Frost resistance of products varies from 35 freeze-thaw cycles, which is undoubtedly a pretty good indicator.
8. The advantages also include the ability to make blocks with your own hands. This can save a little budget. Those who want to organize a small business will be able to try themselves as a manufacturer. We will talk about the profitability of production later.
9. The prevalence of the material, a large selection of sizes.
10. The closed pore structure is a significant advantage. Thanks to this, foam concrete absorbs moisture somewhat less than some wall materials.
11. Foam concrete is not affected by the biological environment, unlike, for example, wooden buildings. Mold and fungus do not form on it.

The following are the primary drawbacks:

1. First of all, the material is fragile. This is especially evident during the transportation of goods and construction work. Products are easy to cut, but also easily break and crumble.
2. When fixing elements to a wall made of aerated concrete, it is necessary to use only specialized hardware. This is directly related to the special structure of the material. If you want to secure heavy elements with a high level of tear-out, the fixing units will have to be planned and reinforced in advance.
3. The presence of handicraft production increases the chances of buying low-quality products.
4. The ratio of strength and thermal conductivity is somewhat worse than that of other wall materials.
5. Bending strength is also relatively low.

Building shrinkage is an inevitable and common occurrence.

Characteristics of aerated concrete

It’s now time to examine the properties of aerated concrete and its derivatives. To begin, let us ascertain the principal characteristics and attributes of the material that ascertain its competitiveness within the building materials industry.

Physical, mechanical and technical characteristics

Characteristics and attributes:

Name of the indicator	Value and comments
Thermal conductivity in a dry state	From 0.09 for thermal insulation aerated concrete
Frost resistance	From 35 to 150 cycles
Brand of strength	From B 1.5 in accordance with GOST for non-autoclaved aerated concrete, the average indicator at D500 is B3.5
Density	300-1200
Shrinkage	0.3 mm/m2
Water absorption	About 25%
Recommended wall thickness	From 0.4
Environmental friendliness	2
Fire resistance	Does not burn, withstands up to 120 minutes of exposure to high temperatures

Types of aerated concrete

According to GOST, since foam concrete blocks and aerated concrete are both varieties of products made of cellular concrete, they fall under the same classification. It would be pointless to conduct another in-depth analysis of it.

Since some of the indicators of autoclaved and non-autoclaved aerated concrete differ significantly, let’s just use the table to compare them.

Features of aerated concrete blocks: contrasting autoclaved and non-autoclaved goods

Characteristic	Its importance for synthetic hardening aerated concrete	Its importance for hydration hardening aerated concrete
Vapor permeability	0.2	0.18
Frost resistance	35-150 cycles	15-35 cycles
Shrinkage	0.3 mm/m2	From 0.4 mm/m2
Strength grade	B2.5-B5	B1.5-B2.5
Thermal conductivity	From 0.09	From 1.7
External wall thickness	From 400 mm	From 650 mm
Durability promised by manufacturers	Up to 200 years	Up to 50 – 60 years

Given that there are different types of aerated concrete based on density, let’s examine how the products’ thermal conductivity varies.

Relationships between density and thermal conductivity

Type of aerated concrete	Density	Thermal conductivity of products in dry condition.
Structural	D400	0.09-0.1
	D500	0.1-0.12
Structural and heat-insulating	D500	0.13-0.14
	D600	0.15-0.18
	D700	0.18-0.21
	D800	0.21-0.22
	D900	0.22-0.23
Structural	D1000	0.23-0.29
	D1100	0.26-0.34
	D1200	0.29-0.38

Advantages and disadvantages of products and buildings constructed from them

Aerated concrete has certain benefits that are strikingly similar to foam concrete products. Among them are:

1. Low weight of the material, which allows for some savings on the construction of the foundation due to the absence of serious loads;
2. Ease of processing. Aerated concrete is also easy to saw, cut and sand. At the same time, unlike, for example, a ceramic block, highly specialized equipment is not required. You can use a regular hacksaw or any other tool suitable for such purposes.
3. Due to the presence of the above characteristics – high construction speed.
4. Environmental friendliness and fire resistance are also characteristic of aerated concrete.
5. High production efficiency, low cost of products.
6. Possibility of almost any interior and exterior decoration, subject to technology and technical compatibility.
7. Frost resistance indicator enviable for other wall materials. Some manufacturers promise up to 150 freeze-thaw cycles, and set the service life at up to 200 years.
8. High strength characteristics, sufficient for the construction of a multi-story building and, at the same time, a low thermal conductivity coefficient.
9. Resistance to atmospheric – partly biological impact.

The following are the drawbacks:

1. Hygroscopicity of the material. Aerated concrete absorbs moisture better than other products. It has an open pore structure, which only enhances this ability.

During times of below-freezing temperatures, this is particularly dangerous with products. when moisture has the ability to crystallize and start the block’s internal destruction.

Kindly take note! Aerated concrete walls need to be finished correctly from the inside and outside of the building in order to prevent unfavorable effects.

1. With hardware, the situation is the same as with foam concrete. The structure of the material is similar, so when fixing elements, developers face the same problem.
2. Fragility is also characteristic of aerated concrete. It requires careful handling.
3. Shrinkage. It is not uncommon for cracks to appear on finished walls.

This is the extent of the principal drawbacks. As you can see, there are still more benefits, and the majority of the drawbacks can be eliminated with the right finishing and adherence to wall-building protocol.

Comparison of the properties and qualities of materials

Now that we’ve covered every important characteristic and attribute of the materials, let’s examine them and determine which is superior: foam concrete blocks or aerated concrete blocks.

• Thermal conductivity in the comparison of "aerated concrete – foam block". In this indicator – there is no obvious winner. Both one and the other material have close numerical values. Aerated concrete wins only slightly in the strength-thermal conductivity ratio.
• Frost resistance. In this case, aerated concrete definitely wins. It is significantly superior to its competitor in its ability to withstand a large number of freeze-thaw cycles. This is especially true for autoclaved products.
• The materials are environmentally friendly and fire resistant – the same.
• The vapor permeability and construction speed indicators are also similar. Both products are easy to process and have impressive dimensions. Allowing you to erect a building fairly quickly.
• But the geometry of the block is better for autoclaved aerated concrete.
• Foam concrete is significantly ahead of the latter in moisture absorption, which is directly related to the closed pore structure. It absorbs less moisture.
• Soundproofing characteristics are somewhat better for aerated concrete.
• If we talk about appearance, then, according to developers, aerated concrete looks more attractive.
• What is cheaper foam block or aerated concrete? Definitely – foam block. The difference in price is not big. But still it is there.
• The most significant differences between these materials are in their composition and the method of pore formation. The porous structure of foam concrete can be achieved by introducing a blowing agent into the solution. The cells of aerated concrete are obtained as a result of a chemical reaction of lime and aluminum powder, which acts as a blowing agent.

Foam concrete is made up of cement, sand, water, and a foaming agent. Lime, sand, cement, and aluminum powder (or equivalent) make up aerated concrete.

• As for the variability of finishing, as has already been said, there can be a lot of options for both materials. The main thing is to strictly adhere to the rules of application and installation technology. Internal and external finishing must be technically compatible.

Counseling! Finishing from the inside needs to be sealed if the block is bricked from the outside without a ventilated facade near the wall. This is because, in this instance, the block and brick wall layer should not be exposed to moisture or vapor generated within the room. In other words, the possibility of condensation accumulation and its detrimental effects must be ruled out.

• Shrinkage is more characteristic of foam concrete. Aerated concrete also sits down, but the numerical indicator is still lower.
• If we compare the recommended wall thickness, then it can be less for aerated concrete. For foam concrete, this is 63 cm, and for aerated concrete – at least 40 cm.
• It is also worth noting that fragility is characteristic of both products – this is their general drawback. The same applies to fixing fasteners.
• The standard dimensions of the products are also similar. In their assortment, they have both wall and regulations.
• Foam concrete is distinguished by the availability of products with facing, which do not require further decoration. Aerated concrete can not boast of their presence.
• Separately, I would like to note the fact that when decorating both materials, additional costs of processing and reinforcing the surface will be needed. The fact is that both aerated concrete blocks and foam concrete blocks are characterized by low adhesion to finishing materials. This necessitates priming and reinforcing the surface.

The table indicates that aerated concrete still prevails in a higher number of attributes. On the other hand, foam concrete is ideal if low cost and moisture absorption capacity, for example, are your top priorities. As a result, your decision-making process should be primarily driven by your unique preferences and needs for the future building.

Production features

Since the qualities have already been compared, it is important to comprehend how these materials’ production technologies differ from one another. Which of them makes the most sense to produce economically and profitably?

Aerated concrete is a good place to start.

Production of aerated concrete

A specific set of equipment must be purchased in order to plan production. It might vary:

1. Conveyor line. The most automated set of equipment. Human participation is practically excluded. The price is quite high, but the production volume is large.

1. A stationary line is the most budget option. You can choose the completeness yourself, but the speed and daily volume of production will depend on it.

1. Mini line is an economical option. Suitable for home production or small businesses. Used in the manufacture of non-autoclaved aerated concrete. Additionally, you can save money by independently constructing some units, moreover, after producing the required number of products, the equipment can be sold or rented.

Supplies needed for manufacturing:

• Quartz sand;
• Cement;
• Aluminum powder;
• Water;
• Lime;
• Specialized additives.

In a factory, the following steps are involved in the manufacturing process:

1. All the necessary components are fed into the dispenser;
2. It, in turn, feeds them into the aerated concrete mixer, where they are thoroughly mixed;
3. After this, the finished solution enters the mold;
4. Then the process of gas formation occurs;
5. A single block slab is tilted and sent for cutting, which is carried out automatically.
6. The last stage is autoclaving of the products, after which they are sent to the finished goods warehouse.

In theory, home production without an autoclave is not all that dissimilar from the procedure described above. Everything is done by hand, which involves much more time and labor expenditures.

After gas formation, the excess mixture is usually cut off and the finished mixture is poured into ready-made molds of the necessary sizes. Within 28 days, the blocks acquire technical strength as they harden in the open air. They are occasionally further moistened.

Step-by-step analysis of the foam concrete production process

There are some similarities in the production process of foam concrete.

The following is a list of the gear that is required:

• Again, this can be an automated conveyor-type line with maximum productivity;
• A stationary, less expensive line. Requires a certain number of workers. The volume of manufactured products will also be smaller.
• Mini-line for small-scale and home production.

Several technologies can be used to produce foam concrete:

• Classical method;
• Barotechnology;
• Dry mineralization method.

In the first instance, the guidelines are as follows:

1. First, a cement-sand mixture is prepared;
2. A foaming agent is added to it, and everything is thoroughly mixed;
3. Next the finished solution is placed into molds and, after hardening, is cut if the mixture is poured in a single mass;
4. In the autoclave method of hardening, the products are processed in an autoclave.

The ability to create a foamed solution naturally—without the use of a foam generator—by applying excess pressure is what defines barotechnology. To prepare for the subsequent pouring of a monolithic structure, such a mixture can be prepared right on the construction site.

Adding dry materials to the foam flow is what distinguishes the dry mineralization process. It is fed through a unique apparatus called a porizer. The mixture being built is actively supplied on a continuous basis using this method.

Combined manufacturing technology

The process of making foamed aerated concrete has recently spread a little. Because it combines elements of several technologies at once, products made from it have the qualities of both gas and foam concrete. That is, during the production process, foam and gas porization both happen.

Experts suggest that insulating structures might be the most pertinent application for this kind of material. Its strength will be suitable given that it has the lowest thermal conductivity coefficient.

Briefly about the profitability of production

In terms of economic viability, it is definitely high.

Material gain is dependent on numerous variables:

• Features of the region and its purchasing power;
• Level of investment;
• Advertising;
• Speed ​​of production in relation to sales and much more.

However, in general, it is very difficult to make a business unprofitable given that product popularity is growing annually. Even if we assume that the retail price will be 3000 rubles and the total cost of production will be 2200 rubles, we still have a respectable net profit of 800 rubles per m3.

Statistics show that a small output volume and cheap costs result in an average payback of six months. Yes, it’s an admirable outcome.

Calculation of aerated concrete blocks and glue

ROOM PARAMETERS:PARTITIONS:

It is important to consider the advantages and disadvantages of both foam blocks and aerated concrete when making a decision regarding your construction project. Aerated concrete is perfect for safe and energy-efficient constructions because it provides superior fire resistance and insulation. However, foam blocks are lighter and frequently simpler to work with, which can expedite construction. To assist you in selecting the material that best suits your needs, this comparison will examine how these materials compare in terms of price, functionality, and usefulness.

Technology for laying block products made of foam and aerated concrete

• Laying must be done on a flat surface. If there are any irregularities or defects, they are corrected.
• The first blocks are laid in the corners. They will serve as guidelines in the future.
• A thread stretches between them.
• It is recommended to lay the first row using mortar for better adhesion to the base.
• Next, the entire first row is laid.
• If there remains a gap that is unequal in size to the block, the product should be cut to the required size using a suitable tool.
• The second row begins to be laid with an offset of approximately 25-30%.
• Experts advise to build a wall from this moment using specialized glue. The thickness of the layer will be smaller, and, therefore, the cold bridges will be reduced, which, in turn, will contribute to better heat retention in the future room.
• Adjustments are made using a building level and a rubber hammer. It is quite heavy, but at the same time it will not cause mechanical damage to products if used correctly.
• The first and every 4th row are reinforced.
• After completing the masonry of the walls, it is recommended to install an armored belt.

The entire explanation of the principles of laying products from both materials can be found in the article’s video.

Calculation of the number of foam blocks

Selection of block size, LxHxD

Total length of walls, meters

Average height of walls, meters

Total area of ​​window and door openings, m2

Calculate

m 3PC.m 3PC.

Feature	Aerated Concrete	Foam Block
Density	Lightweight but strong	Even lighter, good thermal insulation
Insulation	Good thermal and sound insulation	Excellent thermal insulation, slightly better soundproofing
Strength	Strong enough for most applications	Generally strong, but can be less durable
Workability	Easy to cut and shape	Very easy to cut and handle
Cost	Moderate cost	Usually less expensive
Environmental Impact	Low, often made from recycled materials	Low, but depends on the production process
Common Uses	Residential and commercial buildings	Residential and some commercial applications

It is evident from a comparison of foam blocks and aerated concrete that each material has advantages and disadvantages that vary based on the particular requirements of a building project. When constructing quiet, energy-efficient buildings, aerated concrete is a great option because of its superior thermal insulation and soundproofing capabilities. Its lightweight design also facilitates handling and speeds up construction. It’s crucial to keep in mind, though, that it might be more vulnerable to moisture damage and might need more waterproofing techniques.

However, foam blocks offer a good substitute because of their strong durability and simplicity of installation. Because they are resistant to water penetration, they work especially well in areas that are frequently damp. They are therefore a good choice for areas with unpredictable weather. While foam blocks may not be as effective at soundproofing as aerated concrete, they do provide good thermal insulation.

The decision between foam blocks and aerated concrete will ultimately be based on a number of variables, such as the project’s requirements, budget, and local climate. Making the best choice will depend on your build’s priorities, which may include insulation, durability, or ease of use. Both materials have a lot to offer. Having a clear understanding of these attributes will help you choose the material that best suits your construction objectives.

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