Foam concrete or aerated concrete: advantages, disadvantages – comparison of technical characteristics

With so many options available, selecting the best material for your construction project can be a difficult task. Aerated concrete and foam concrete are two common options, each with their own advantages and disadvantages. You can make an educated choice by comparing and understanding their technical features.

Foam concrete is a lightweight, adaptable material with superior thermal insulation qualities. It is made by combining a foaming agent with cement to produce a material that has a high air bubble content. Because of its composition, foam concrete is simple to work with and install, lowering the overall weight of buildings while offering good thermal efficiency.

Another lightweight option is aerated concrete, sometimes referred to as autoclaved aerated concrete (AAC), which is made by mixing aluminum powder with a cement mixture. Aerated concrete gets its unique porous structure from hydrogen bubbles created by the ensuing chemical reaction. Its superior thermal insulation, fire resistance, and longevity are highly praised qualities of this material.

There are a few things to take into account when comparing foam and aerated concrete. Foam concrete can be used for a number of purposes, such as floor screeds and void filling, because it is typically less expensive and simpler to make on-site. However, despite being more costly, aerated concrete has a higher structural strength and is frequently utilized for large-scale projects and load-bearing walls.

Each material has a unique set of benefits and possible drawbacks. Compared to aerated concrete, foam concrete may have a lower compressive strength due to its lower density. Aerated concrete, on the other hand, necessitates a more intricate production procedure and exact quality control, which may lengthen project durations and raise costs.

In conclusion, the decision between foam concrete and aerated concrete is based on the demands of your particular project, your financial constraints, and the performance qualities you want. You can choose the ideal material for your construction project by assessing the benefits and drawbacks of each one.

Characteristics of aerated concrete

Products are separated into categories according to their constituent parts, such as foam concrete and aerated concrete of autoclaved and non-autoclaved production, depending on the production technology and requirements for the material.

One kind of porous concrete with good technical qualities is aerated concrete (picture). Primary ingredients: aluminum powder, quarry quartz sand, lime, and cement.

The ingredients in aerated concrete that produce gas through a chemical reaction—typically powdered aluminum—cause the foaming process.

The cells of aerated concrete are formed by the release of hydrogen when alkali and powdered aluminum are mixed. Different types of aerated concrete with varying densities can be produced because it is simple to modify the size of the concrete cells during the material’s production.

Procedure for the production of aerated concrete

A dense water vapor atmosphere is used in furnaces known as autoclaves to heat treat aerated concrete.

The following procedures are carried out in order to create aerated concrete:

1. mix the mixture with all the components;
2. pour into a prepared form, where the concrete "swells" as a result of chemical reactions;
3. remove excess mixture ("cap") with a string;
4. we carry out autoclave finishing of the material;

Advantages of aerated concrete masonry blocks

An order of magnitude more expensive than other common building materials, aerated concrete masonry blocks have several significant benefits.

• low weight — significantly lower load on the foundations of buildings being erected;
• large format of aerated concrete blocks—increases the rate of masonry;
• the air exchange and thermal conductivity characteristics of the material contribute to comfortable living in a residential area;
• aerated concrete differs from other similar materials in its ease of processing, which allows you to cut out all sorts of architectural elements from it, and significantly simplify the installation of utility lines;
• aerated concrete is a safe material according to all requirements, not susceptible to various biological factors;
• due to the correct geometry of the block, allows to minimize errors in laying aerated concrete blocks, which makes it possible to use a special glue that prevents the creation of cold "bridges" in the walls of the premises;

• due to the smooth and leveled surface of the walls the time for finishing works is reduced.

A variation of porous concrete, foam concrete is made of quartz sand and mineral binders with precisely placed cells throughout the material’s volume (see photo). In contrast to aerated concrete, foam concrete requires the addition of foaming agents to create porosity.

Production of foam concrete at a construction site

The technologies used to produce foam concrete are rather straightforward. As a result, creating foam concrete on a construction site is a simple task that you can do yourself.

A foam generator is filled with water and prepared foam extract. Using a foam generator, technologically prepared special foam is added to the cement and sand mixture.

As the components are thoroughly mixed, the mass takes on a porous structure. The completed mass is then fed into the installed forms—where the formation (hardening) of foam concrete blocks occurs—using a sleeve that is attached to the mixer.

Foam concrete can be produced entirely on the construction site, without the need for any additional tools or equipment. Two to three weeks after production, foam concrete reaches its design strength.

Advice: It’s important to remember that the quicker the mixture mixes, the fewer mechanical disturbances in the foam you’ll see when combining the final solution and foam.e. You’ll receive a safe foam concrete.

Equipment for the manufacture of foam concrete

In the equipment photo set, there is a brief description and instruction on how to manufacture foam concrete blocks under construction site conditions.

The foaming agent, or foam generator, is the primary piece of equipment used to produce foam concrete. The foam generator is comprised of a lower tank that holds a foaming agent and water mixture. It is connected to the central water supply system via a hose; if the tank is empty, manual water filling is permitted.

We create pressure with a compressor, which starts the foaming process and causes the foam to exit into the concrete mixer. You can control the foam supply and, in turn, the porosity of the final product by turning the valves on the foam generator body. This enables you to obtain foam concrete blocks with the intended design strength and the required grade.

Where foam concrete is used

• manufacturing of foam blocks for the construction of residential buildings and the construction of partitions;
• monolithic construction;
• sound and heat insulation of walls, floor slabs and floors;
• roof insulation;
• pipe insulation (both in the manufacture of pipes and at the place of use – in special formwork);

To make the greatest choice for your building project, it’s critical to comprehend the unique benefits and drawbacks of both foam concrete and aerated concrete. Because of its superior thermal insulation and ease of handling, foam concrete is a great material for lightweight constructions. However, aerated concrete has better strength and longevity, making it ideal for larger buildings and load-bearing walls. You can compare the technical properties of different materials, including density, compressive strength, thermal conductivity, and ease of use, to ascertain which one best suits the particular requirements of your project.

Comparison of the performance characteristics of foam concrete and aerated concrete

Considering the specifications required for building your own home, let’s attempt to compare foam and aerated concrete.

The following are some similarities between foam concrete and aerated concrete: nearly identical production requirements and standards apply to both products. However, there are notable distinctions.

These two concretes have the following qualities:

• Aerated concrete, due to heat treatment, is a more durable material. But it absorbs water very strongly, which adds a certain amount of labor intensity when carrying out finishing work.
• Foam concrete, due to its “bubble” structure, unlike aerated concrete, does not absorb moisture at all. The foam concrete material is characterized by a closed cell design. Cells (bubbles) in the body of the material are isolated from each other. As a result, at the same concentration, a block of foam concrete does not submerge in water, but a block of aerated concrete sinks.
• Due to the low moisture absorption rate, foam concrete is characterized by higher coefficients of thermal protection and frost resistance. Due to the above characteristics, foam concrete is allowed to be used in rooms with high humidity, where the use of aerated concrete is unacceptable.
• Now you need to compare foam concrete blocks and aerated concrete blocks. The cost of manufacturing foam concrete blocks is 25% less than that of similar-sized aerated concrete blocks. All this is explained by the fact that the foaming agents used in the production of foam concrete blocks are much cheaper than the gas generators required for the production of aerated concrete.

• Better thermal conductivity
• Correct block geometry
• No block shrinkage during laying
• Higher frost resistance

• High price
• Increased hygroscopicity
• Lower sound insulation

• Lower price
• High moisture resistance
• High sound absorption

• Errors in block geometry
• Lower thermal conductivity
• Material shrinkage
• Lower frost resistance

Thus, the above comparison between aerated concrete blocks and foam concrete does not support aerated concrete blocks.

Polystyrene concrete – what is it?

Another kind of porous concrete is polystyrene concrete. This kind of concrete has foamed polystyrene as a filler.

The primary characteristic of the material that is being presented is its ability to change density over a very large range. As a result, this material can be used for both thermal insulation and building structure construction.

The ability to combine the best qualities of concrete and polystyrene’s thermal insulation capabilities into a single product allowed for the creation of polystyrene concrete’s ideal attributes.

High load-bearing characteristics, fire safety, decay resistance, thermal insulation capability, enhanced hydrophobicity, and frost resistance.

Application of polystyrene concrete

Using concrete made of polystyrene:

• classical housing construction;
• monolithic structures;
• sound and heat insulation;
• implementation of non-standard solutions;

Production of polystyrene concrete

Concrete mixers with forced mixes are used to prepare polystyrene concrete. To achieve optimal adhesion and a robust homogeneous bond between the polystyrene in the solution, firstly add saponified wood resin (SDO) along with the granulated polystyrene to the mortar mixer. Next, add water and load the cement.

Till the mixture acquires a homogenous plastic mass, the entire mixture is thoroughly mixed. The material must have more plasticity in order to keep polystyrene granules from surfacing when the mortar mixture is being laid into a form or formwork with a deep vibrator.

Equipment for the production of polystyrene concrete

Tools used on a building site to produce polystyrene concrete:

Technical characteristics of polystyrene concrete in comparison with foam concrete and aerated concrete blocks

In comparison to other foam concrete, is it profitable to produce and use polystyrene concrete? We’ll contrast aerated concrete, foam concrete, and concrete made of polystyrene.

Excellent thermal and soundproofing material is polystyrene concrete. This allows for the finished structure’s sound insulation and insulation at no additional cost. Polystyrene masonry blocks are relatively light in weight, which considerably lessens the load on the building’s foundation.

Similar in quality to wood, polystyrene concrete is also simple to work with. elevated environmental attributes. The frost resistance index of these "competitor" blocks is lower than that of foam concrete and aerated concrete because of the significantly lower moisture absorption.

Reduced mechanical load resistance when compared to foam and aerated concrete. Door block installation quality is impacted by the material’s low density. They become very loose very quickly after that.

The adhesion of polystyrene concrete walls to plaster mortar is reduced. Compared to foam concrete and aerated concrete blocks, polystyrene concrete blocks shrink three times more.

Concrete blocks made of polystyrene don’t burn, but they also can’t withstand fire. The polystyrene granules lose their ability to withstand heat when exposed to high temperatures in close proximity to an open fire.

Comparative table of some concretes’ technical and physical properties (average values):

Materials	Average density, kg/m³	Weight of 1m³/kg	Thermal conductivity, W/m³	Frost resistance, cycle	Moisture absorption, %	Ultimate strength, M/Pa
Hollow silicate brick	1825.00	1725.00	1.14	25.00	16.37	17.51
Hollow clay brick	1625.00	1500.00	0.78	25.00	12.35	14.75
Expanded clay concrete	1050.00	700.03	0.85	25.00	18.00	5.50
Foam concrete	750.00	495.34	0.23	35.00	20.00	12.58
Autoclaved aerated concrete	750.00	495.34	0.23	35.00	14.00	6.30
Polystyrene concrete	375.00	375.00	0.11	114.00	6.00	2.17

Characteristic	Foam Concrete	Aerated Concrete
Advantages	Good thermal insulation, lightweight, easy to produce on-site	Excellent thermal insulation, high strength, precise dimensions
Disadvantages	Lower strength, uneven surface, less durable	More expensive, harder to produce, needs special tools for cutting
Density	400-1600 kg/m³	300-800 kg/m³
Compressive Strength	0.5-10 MPa	2-5 MPa
Thermal Conductivity	0.1-0.4 W/m·K	0.08-0.2 W/m·K

The particular requirements of your construction project will ultimately determine which type of concrete—foam or aerated. There are some clear benefits to both materials as well as some disadvantages that need to be carefully evaluated.

Foam concrete is well-known for being lightweight, having superior thermal insulation, and being simple to use. Because of its extreme versatility, it can be used for a wide range of tasks, such as soundproofing, thermal insulation, and void filling. Its lack of strength and longevity in comparison to aerated concrete, however, may be a drawback for structural applications.

Conversely, aerated concrete has higher strength and load-bearing capacity. It is a great option for both residential and commercial construction because it is lightweight and offers superior thermal insulation. Its production process includes autoclaving, which increases its cost in comparison to foam concrete but also improves its structural integrity.

Think about things like the project’s specific application, budget, and load-bearing requirements when choosing which material to use. Aerated concrete is better for projects requiring more substantial structural support, while foam concrete might be more appropriate for non-structural applications where insulation is important. Making an informed decision that fits your construction needs and objectives will be made easier if you are aware of these distinctions.

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