Expanded clay concrete or foam concrete – which is better: comparing materials and products made from them

Appropriate material selection is essential for any construction project. Expanded clay concrete and foam concrete are two common options for lightweight concrete applications. It’s critical to recognize the distinctions between the two materials because they each have special uses and advantages.

Cement, water, and clay pellets are combined to create expanded clay concrete, also referred to as lightweight aggregate concrete. After being burned in a kiln, these pellets form a porous, light structure. Because of its superior soundproofing and thermal insulation qualities, this kind of concrete is highly prized for use in residential structures.

On the other hand, foam concrete is made by mixing in a foaming agent with the cement mixture. As a result, air bubbles are created in the concrete, making it flexible and lightweight. Foam concrete’s remarkable insulating qualities and ease of installation make it a popular choice for walls, floors, and roofs.

Thermal insulation, soundproofing, strength, and cost are all important considerations when comparing expanded clay concrete and foam concrete. Every material has advantages and works well in certain situations. You will be able to choose the right material for your project by being aware of these factors.

Main characteristics of expanded clay concrete

One of cellular concrete’s primary rivals is expanded clay concrete blocks. A portion of this can be attributed to the indicators of qualities and properties being similar. However, there are also essential distinctions. Let us ascertain their identities.

Properties and qualities

Cement, sand, water, expanded clay, and specific additives are combined to make expanded clay concrete. Expanded clay provides lightness, and cement provides strength. Additionally, the latter’s superior thermal conductivity enhances the products.

Let’s use a table to review some of the material’s key features.

Technical and useful characteristics of expanded clay concrete are indicated by:

Characteristic name	Value	Comments
Thermal conductivity	0.15-0.45	Thermal conductivity depends on many factors, such as density, composition of raw materials and percentage of moisture in products. Values ​​of 0.15-0.45 are typical for blocks in a dry state.
Frost resistance	From 50 cycles	Frost resistance of expanded clay concrete can reach 200 freeze-thaw cycles. This is an enviable indicator for almost all of its competitors.
Average density	400-2000	Depending on strength, there are several types of expanded clay concrete, we will talk about this a little later.
Strength	50-150 kg/cm2	The products are quite durable. This quality is perfectly combined with a low thermal conductivity coefficient, which allows you to erect buildings in several floors and, at the same time, save on insulation.
Shrinkage	0%	A noticeable advantage of expanded clay concrete is the lack of a tendency to shrinkage.
Water absorption	18%	The material tends to absorb moisture, but this indicator is quite competitive. For example, if you compare expanded clay concrete with aerated concrete, then the latter has a numerical value of water absorption equal to 25%.

Classification and scope of application

Multiple classifications exist for expanded clay concrete and its derivatives. Every one of them is founded on a specific attribute or quality. Let’s think about them.

Expanded clay concrete can be made in the following ways, depending on the product type:

• Wall, foundation and ventilation blocks. Represent building elements with standard parameters.
• Wall and partition panels. Usually used as a material for installing the outer part of walls or partitions. Also used when filling the frames of reinforced concrete structures.
• Floor and roof slabs. Produced in the form of a monolithic or hollow structure, reinforced with a frame. The products are characterized by high strength indicators, and therefore are actively used in the construction of buildings that are subject to heavy loads.

Expanded clay concrete can be: depending on the concrete’s density

1. Heat-insulating;
2. Structural and heat-insulating;
3. Structural.

The first kind is utilized as an insulating material. It has a low density of between 400 and 500. These products are not meant to support heavy loads.

When building walls and partitions, structural and heat-insulating expanded clay concrete is actively utilized. Its thermal conductivity is quite acceptable and its density is higher. There are 600–1000 kg/m3 of density.

The density of structural expanded clay concrete is higher. The numerical value fluctuates between 1300 and 1800 kg/m3. It is employed in the building of structures intended to support heavy loads.

Denser expanded clay concrete is also available; indications for this material can reach 2000 kg/m3. It is employed in the building of foundations and other structures that call for the use of materials that are exceptionally durable. The material’s range of application serves as another classification for expanded clay concrete.

In light of this, the goods may serve as:

• Wall blocks;
• Partition blocks;
• Foundation blocks;
• Ventilation blocks.

• Wall and partition blocks, as the name suggests, are used in the construction of walls and partitions, respectively.
• Foundation blocks can be of several types: solid (or FBS) and hollow (FBP). Used in the construction of basements and plinths. Products are large-format, without internal reinforcement.
• It is worth noting that expanded clay concrete is the only lightweight concrete material that is used in the construction of building foundations.
• Ventilation blocks are specialized products with through channels for wiring utilities and air exchange. Standard sizes are 390*188*190.
• In accordance with the structure, products can be solid and hollow.
• Solid blocks are characterized by greater density and thermal conductivity. They are actively used for the construction of external walls of structures.
• Hollow – lighter products, their strength is lower, and the ability to retain heat is better. There can be a different number of voids: from 4 to 8 pieces.

Both through and non-through voids are possible.

Products can vary depending on how wall blocks are used.

• Ordinary, used in the construction of walls and requiring subsequent finishing;
• Facing. These products have cladding on one or two sides. Such blocks do not require subsequent finishing.

Concrete blocks made of expanded clay may have various surface structures. It might be:

• Smooth;
• Chipped;
• Ribbed;
• Sanded.

• Smooth products are not processed, have the same surface on all sides.
• Ribbed are characterized by the presence of depressions and protrusions.
• Chipped are distinguished by an uneven surface, protrusions can reach 8 mm.
• Grounded products are processed and are distinguished by a rough surface.

It’s also important to remember that the products’ ends may have tongues, grooves, or ridges. Either rounded or straight corners are possible.

Advantages and disadvantages of the material

The following are some of the primary benefits:

1. Despite the fact that expanded clay concrete is inferior to cellular concrete in terms of thermal conductivity, this quality can still be considered an advantage. The required wall thickness for an average region is only 50 cm, which is a good indicator. Especially if you take into account the ratio of density and thermal conductivity.
2. The high load-bearing capacity of the material allows it to be used even when constructing building foundations.
3. Expanded clay concrete is not subject to shrinkage, which is a significant advantage.
4. The frost resistance indicator reaches 200 cycles. This is twice as much as, for example, foam concrete.
5. The reasonable price of the product makes it accessible to a wide range of developers.
6. A significant plus is the environmental friendliness of the material.
7. Blocks do not burn.
8. Comparatively large sizes will ensure high construction speed.
9. Expanded clay concrete is resistant to biological influences, it is not prone to the appearance of fungus and mold.
10. Fasteners are easily fixed into a wall made of this material, the presence of specialized hardware is not necessary.
11. Another advantage is the ability to independently produce products. To produce blocks with your own hands, you do not need expensive equipment, its set is minimal. And the instructions below will help you with this.

Like any material, expanded clay concrete has a lot of benefits in addition to some drawbacks.

Essentially, they are as follows:

1. Products are not as easy to process as, for example, cellular concrete. They are much more difficult to saw, which is directly related to the abrasive quality of the products.
2. Expanded clay concrete is hygroscopic, it needs protection from the harmful effects of moisture.
3. Since the production technology is not complicated, the spread of handicraft production takes place. As a result, the chances of purchasing low-quality products increase significantly.
4. Blocks are fragile, mechanical impacts are extremely undesirable.

Expanded clay concrete doesn’t generally have any major drawbacks.

What is foam concrete

It’s time to learn more about foam concrete, including its properties. Let us begin with the primary attributes and characteristics that developers find particularly appealing.

Overview of the main properties

Use the table, please. Features of foam concrete include:

Name of the indicator	Its value
Thermal conductivity	From 0.09
Frost resistance	15-100 cycles
Density	300-1200
Strength	From B 1.5
Environmental friendliness	2
Fire resistance	Does not burn
Recommended minimum wall thickness	From 0.5 m
Water absorption	10-16%

Kindly take note! The material’s competitors find the thermal conductivity index particularly impressive. Still, it is important to remember that this is normal for dry products. The numerical value rises to operational humidity. The highest possible value is 0.4.

The products’ density directly affects their capacity to hold heat, just like it does in the case of expanded clay concrete:

• Frost resistance is quite high, but foam concrete is still inferior to some materials.
• The density of the products allows for the construction of buildings up to 12 meters in height.
• Water absorption is not so high. The ability to absorb moisture is somewhat reduced due to the special closed pore structure of foam concrete.

It is now worthwhile to give the material’s composition a cursory examination. A mixture of cement, sand, water, foaming agent, and specialty additives is used to make foam concrete. Because the foaming agent causes the solution to swell, foam concrete has a cellular structure that contributes to its light weight and superior thermal insulation properties.

Important! Accordingly, the more pores, the lower the density and thermal conductivity.

Types of material and products made from it

GOST has categorized foam concrete into multiple categories. Let’s take a closer look at them.

Similar to expanded clay concrete, there are various types of foam concrete based on density:

• Heat-insulating;
• Structural and heat-insulating;
• Structural.

Using the table, let’s examine the primary distinctions between the aforementioned types and the range of applications for the products.

The products’ range of applications and the relationship between foam concrete’s density and thermal conductivity:

Type of foam concrete	Average density indicator	Thermal conductivity coefficient	Main areas of application
Heat-insulating	300-400	0.09-0.11	Used as a material for insulation, cannot withstand loads due to the low density and strength of the material.
Structural and heat-insulating	500-900	0.12-0.25	It is used in the construction of walls and partitions, it is used in the construction of buildings several stories high. Most popular among private developers.
Structural	1000-1200	0.26-0.34	The most durable type of foam concrete. Able to withstand significant loads. Used for the construction of load-bearing walls and structures. Needs additional insulation, due to the high thermal conductivity coefficient.

It is important to note that structural-porous foam concrete blocks are those that have a higher density than structural blocks. They have a density of 1500 kg/m3.

They are made in small batches in response to specific orders, and they are not commonly used. GOST does not regulate them.

Foam concrete can be: depending on how it’s hardened

1. Autoclaved. Such products are processed in special chambers – autoclaves. It is there that the blocks reach technical maturity, by exposing them to high temperature and pressure.
2. Non-autoclaved. Such blocks harden in natural conditions. They reach brand strength only after 28 days.

Their characteristics include reduced strength, resistance to frost, and increased fragility. They have a more gray hue.

It is possible to make foam concrete using different types of binder:

1. On cement;
2. On lime;
3. On slag;
4. On mixed binder;
5. On ash binder.

Over 50% of the main component’s content can be found there. 15% is the minimum threshold.

Products can vary depending on the kind of siliceous component.

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

It’s also important to remember that foam concrete products can have geometric deviations from one another. Let’s use the table to think about them.

Foam concrete block accuracy categories:

Name of deviation	Blocks of the first category	Blocks of the second category	Blocks of the third category
By size	No more than 1.5 mm	No more than 2 mm	No more than 5 mm
Diagonally	No more than 2 mm	No more than 4 mm	No more than 7 mm
Chips in corners	No more than 3 mm	No more than 5 mm	No more than 8 mm
Chips on edges	No more than 3 mm	No more than 5 mm	No more than 10 mm

Kindly take note! For each indicator, a maximum of 5% of the products in a batch may exceed the aforementioned deviations. No more than two pieces may have chips in the corners of a block.

Blocks made of foam concrete may have one or two faced sides. These products don’t need to be finished externally afterwards. Liquid foam concrete is also utilized in addition to blocks.

It is mostly employed in:

• For roof insulation;
• When pouring screeds and bases for underfloor heating;
• When creating monolithic structures

Strengths and weaknesses

Foam concrete offers a lot of advantageous characteristics.

• Environmental friendliness and fire resistance.
• The low weight of the products will reduce the load on the foundation of the building.
• Large dimensions of the block contribute to a significant increase in the speed of construction.
• The material is easy to process, it is easy to saw and polish. At the same time, it does not require the use of highly specialized tools.
• Due to the closed pore structure, water absorption is not so high and is about 10%.
• The cost of the product is one of the lowest among cellular concretes.
• The frost resistance, density and thermal conductivity indicators are good enough for the construction of a practical and durable building.
• The vapor permeability of the material is able to create the most favorable microclimate. Foam concrete is able to absorb excess moisture and give it off when the air is dry.
• A variety of sizes and a large selection of manufacturers are also a significant plus.
• The ability to soundproof will protect those present in the building from extraneous sounds.
• Ease of manufacture and the possibility of self-production.

There are also weaknesses.

The primary drawbacks are:

• Poor adhesion to finishing materials, which causes the need for additional costs for primer, reinforcing mesh and expensive plaster mixes.
• Poor fixation of fasteners and the need to use special hardware. To fix heavy objects, it is necessary to plan the fastening units at the design stage and strengthen them.
• The presence of handicraft production is another disadvantage. You can protect yourself from buying low-quality products only by checking the availability of relevant documentation from the supplier in the form of certificates of conformity.
• Fragility of products. Foam concrete easily crumbles, breaks under mechanical stress.
• Blocks are prone to shrinkage, which often leads to cracks in the masonry.

Comparison of materials

Let’s now compare the two materials to determine which is superior: foam blocks or expanded clay concrete blocks?

Use the table, please. Which type of concrete—foam or expanded clay—works better?

Name of the indicator	Comparison and analysis of the indicator
Frost resistance	Expanded clay concrete clearly wins in this indicator. It is characterized by. As already mentioned, up to 200 freeze-thaw cycles.
Density	Also surpasses expanded clay concrete in density. The numerical value can reach 2000 kg / m3.
Thermal conductivity	But foam concrete wins in thermal conductivity, which is directly related to the lower density of the material.
Shrinkage	For expanded clay concrete, shrinkage is not typical at all, foam concrete, in turn, cannot boast of this.
Complexity of processing and speed of construction	Expanded clay concrete is difficult to process. As for the speed of construction, then, apparently, foam concrete is somewhat ahead of its competitor.

Each material is beneficial in its own unique way, as you can see. Additionally, choosing between foam concrete and expanded clay concrete would probably be difficult. Making the best choice requires determining which attributes are most important to you; in this situation, answering the question "what is better?" will be much simpler.

Understanding the particular benefits and drawbacks of each material is essential when choosing between expanded clay concrete and foam concrete. Because of its exceptional strength and thermal insulation, expanded clay concrete is a great choice for load-bearing structures. Conversely, foam concrete is ideal for non-load-bearing applications and insulation because of its exceptional lightweight qualities and ease of handling. Through a comparative analysis of these materials, builders and homeowners can make well-informed decisions that balance performance, durability, and cost for their particular projects.

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Overview of the production cycle

Since the attributes and characteristics have already been compared, it is worthwhile to quickly go over the manufacturing characteristics of both materials and examine the degree of labor costs and complexity. Maybe, when making a decision, this will become a significant debate.

Features of foam concrete manufacturing

The following methods can be used to produce foam concrete:

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

The most widely used technology is classical.

The following are the stages of work:

• A foaming agent is added to the cement mortar;
• The finished solution is poured into molds;
• Semi-finished products are stripped (if manufactured in a single layer, they are pre-cut into standard sizes);
• Processed in an autoclave or kept for 28 days with a non-autoclave production method.

The components are mixed dry in the dry mineralization process, which is different.

The process of barotechnology involves feeding foam under high pressure without the need of a foam generator. On a building site, the technique is frequently applied to continuous production.

A variety of tools are available for use:

1. Mini-line. Characterized by a minimum daily output volume. Suitable for home production and small businesses.
2. Stationary line – more expensive, you can choose the configuration yourself. Higher productivity, less labor costs.
3. Conveyor line – the most automated. Used in large-scale production, the daily output volume can reach 200 m3. Characterized by minimal human involvement.

Such a line produces smoother, higher-quality products from a geometric standpoint.

Expanded clay concrete production: equipment overview and step-by-step analysis of the work process

You’ll also need a few pieces of equipment to make expanded clay concrete. The lines can be partially operated manually or entirely automated (mini-line).

A typical assortment of equipment, supplies, and tools for use at home consists of:

• Concrete mixer;
• Vibration press;
• Cement, sand, water, expanded clay and plasticizer (liquid soap can be used);
• A container in the form of a bucket or trough.

The order of the tasks is as follows:

• The solution is mixed. Water is poured first, and then all the ingredients;
• The finished solution should resemble sour cream in consistency;
• The next step is molding. For this, you will need vibratory pressing equipment, which, using vibration, compacts the solution.
• Excess mixture is removed with a special knife;
• The metal plate with the products is dried for several days, after which they are unmolded;
• Like foam concrete, expanded clay concrete products need to gain strength within 28 days.

• It is also worth mentioning the presence on the construction industry market of a combined material called expanded clay foam concrete.
• It is manufactured using modern technology. The essence of the method is as follows: components in the form of water, expanded clay, cement and foaming agent are sequentially loaded into the mixer. The latter is supplied in the form of a solution by means of a sprayer.
• This innovation refers to the technology of manufacturing wall panels from expanded clay foam concrete.
• The main purpose of such production is to obtain a fine-pored structure of the solution with closed pores, which undoubtedly led to a decrease in thermal conductivity and density, due to an increase in the amount of air in the solution and a uniform distribution of cells.

Briefly about the profitability of production of both materials, possible prospects

In terms of economic viability, the production of foam and expanded clay concrete is profitable.

The outcome is primarily determined by several factors, such as:

• Features of the region, including purchasing power;
• Investments in business, type of equipment and productivity;
• Speed ​​of sales of finished products;
• Business expenses, number of employees and much more.

Whatever the situation, it is advised to start with creating a business plan that can accurately project the outcome and account for all potential revenue and expenses.

Assuming that the cost of one meter of expanded clay concrete is 2,200 rubles and that it can be sold for 3,200, you can make 900,000 per month if you can produce 30 m3 (a small volume) each day and sell them. You must admit that this is a respectable wage.

The approximate cost of a set of budget equipment is 800,000. It is simple to compute that, under ideal circumstances, it can pay for itself in a month or two.

Feature	Expanded Clay Concrete	Foam Concrete
Insulation	Good thermal insulation	Excellent thermal insulation
Strength	High compressive strength	Moderate compressive strength
Weight	Heavier	Lighter
Cost	Generally more expensive	More affordable
Durability	Long-lasting	Moderately durable
Applications	Ideal for load-bearing walls	Great for non-load-bearing walls

Both foam concrete and expanded clay concrete have advantages and can be used for various kinds of projects. Because of its exceptional durability and thermal insulation, expanded clay concrete is a fantastic material option for buildings that must withstand challenging circumstances.

However, foam concrete can save time and labor costs during construction because it is lightweight and simple to work with. It is frequently utilized in applications where weight reduction is crucial and is also an efficient insulator.

Which option is best for you will depend on your individual needs. Expanded clay concrete might be a better choice if you need a sturdy material that can withstand heavy loads and harsh weather. Foam concrete might be the best option for projects where weight and ease of installation are more important considerations.

Ultimately, each material has advantages of its own, and the best option will rely on the specifications of your project. When making your choice, take into account elements like cost, durability, weight, and thermal insulation.

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