Advances in the field of chemistry and the development of excellent foaming agents have allowed for the improvement of the technology of poured cellular concrete, known since 1928. In Western European countries, as well as in Canada, the USA, Australia, China, and India, it has been considered a proven and widely used building material for many years. Annually, about 3 million m³ of Foam Concrete are used worldwide.
What is Foam Concrete?
Foam Concrete is cast cellular Concrete, i.e. cement material with introduced foam which
captures air bubbles in the resulting mass. For its manufacturing, we use cement, water,
foaming agent and filling materials, e.g. fine sand, volatile ash or dust.
Foam Concrete has several characteristic advantages such as:
- Thermal and acoustic insulation
- Frost resistance
- Fire resistance
- High tightness
- Light weight
- Relatively high compressive strength
- Ease and speed of installation
- No need for expansion joints
Unlike other lightweight building materials, Foam Concrete forms a rigid monolith.
How is Foam Concrete produced?
Foam Concrete is produced in a special device directly on the construction site and is delivered to the installation site through hoses. Without additional equipment, it can be delivered to a height of 30 meters and a distance of up to 300 meters.
The air bubbles contained in the mass create a bearing effect, resulting in a highly fluid mass with a yogurt-like consistency. This ensures precise and tight filling of all irregularities, as well as good cohesion and the ability to bond with other materials.
Technical Data Table
| Type | Density (kg/m³) | Compressive Strength (MPa) minimum | Thermal Conductivity (W/mK) | Thermal Resistance (mK/W) U | Modulus of Elasticity after 56 days (MPa) | |||
| Layer thickness (cm) | (MPa) | |||||||
| 10 | 15 | 20 | Static | Dynamic | ||||
| PB 400 | 400 | 0,6 | 0,05 | 0,5 | 0,33 | 0,25 | 810 | 400 |
| PB 600 | 600 | 1,0 | 0,13 | 1,25 | 0,87 | 0,64 | 930 | 470 |
| PB 800 | 800 | 2,2 | 0,17 | 1,66 | 1,11 | 0,83 | 2020 | 910 |
| PB 1000 | 1000 | 2,8 | 0,22 | 2,22 | 1,47 | 1,10 | 3540 | 1380 |
| PB 1200 | 1200 | 4,2 | 0,27 | 2,70 | 1,82 | 1,35 | 4360 | 1940 |
| PB 1400 | 1400 | 6,3 | 0,29 | 2,94 | 1,92 | 1,47 | 6205 | 3060 |
Acoustic Insulation of Foam Concrete:
| Type | Density (kg/m³) | Single Number Values of RA1R and RA2R Indicators in dB, Depending on Wall Thickness in cm | |||||||||||
| RA1R (internal walls) | RA2R (external walls) | ||||||||||||
| 60 | 120 | 180 | 240 | 300 | 360 | 60 | 120 | 180 | 240 | 300 | 360 | ||
| PB 500 | 500 | 31 | 36 | 41 | 44 | 46 | 48 | 30 | 34 | 37 | 40 | 43 | 45 |
| PB 600 | 600 | 33 | 38 | 43 | 46 | 48 | 50 | 32 | 35 | 39 | 42 | 45 | 47 |
| PB 700 | 700 | 35 | 40 | 44 | 48 | 50 | 51 | 33 | 36 | 41 | 44 | 46 | 48 |
Note: The table applies to walls with a 10mm thick cement-lime plaster; wall thicknesses are given without plaster.
Technical Conditions of Foam Concrete:
- Depending on the needs and conditions of application, Foam Concrete is produced with densities ranging from 400 to 1400 kg/m³. Each density has different properties, allowing it to meet various requirements.
- Foam Concrete can be pumped under pressure (e.g., for fillings).
- The recommended minimum layer thickness of Foam Concrete is 5 cm for ceilings, 10 cm for floors, and 15 cm for roads.
- The maximum layer thickness when poured at one time ranges from 20 to 100 cm, depending on the density of Foam Concrete and the ambient temperature. Additional layers can be poured after several hours.
- The minimum ambient temperature during pouring is +5°C.
- Foam Concrete can be easily processed with commonly available concrete tools such as saws, chisels, or drills.
- Excavations in Foam Concrete are repaired by refilling with Foam Concrete or by pouring a sufficiently thin cement slurry to flow into the gaps and spaces between the blocks and bond them together. Due to its high wear resistance,
- Foam Concrete is not used directly on surfaces with heavy loads. After impregnation or surface treatment, it is suitable as a top layer for low-load traffic.
- Like any cementitious material, Foam Concrete accepts impregnations, especially bituminous ones, and hot-bonded membranes, which are useful on roof decks or parking garage floors.
Practical Advantages of Foam Concrete:
- Principle of Maintaining Ground Balance Using Foam Concrete: If the weight of the structure equals the weight of the excavated soil, the structure will have no impact on the ground – no settlement phenomena will occur.
W1 = W2 + W3
ground = Foam Concrete + structure
- Comparison of Traditional and Foam Concrete Road Base Construction:
Structure: A and B
For comparison of construction weight, the following building material weights are assumed:
- Native soil – 1600 kg/m³
- Aggregate – 2400 kg/m³
- Foam Concrete – 1000 kg/m³
- Asphalt – 2400 kg/m³
Construction A (asphalt + Foam Concrete – soil) = 0 kg/m² Construction B (asphalt + aggregate – soil) = 280 kg/m²
In this example, using Foam Concrete completely neutralizes the weight of the structure. The low specific weight of Foam Concrete prevents the effects of ground settlement!