Density
The density of autoclaved aerated concrete is one of the basic features which influences the other properties of products made from this material. Compressive strength and thermal insulation are closely related to it. The more compact and dense the structure of the material, the better its compressive strength and the lower the thermal insulation.
The density of ABK expresses the ratio between the mass of the autoclaved aerated concrete and the volume it occupies, including the pores. This feature has a significant impact on its other parameters. An increase in density is generally associated with an increase in compressive strength and thermal conductivity coefficient. The current PN-EN 771-4 A1:2015-10 standard for masonry elements states that the dry AAC density is usually in the range of 300-1,000 kg/m3.
Classification of AAC masonry units according to dry gross density from the national annexe to the PN-EN 771-4 standard Requirements for masonry units – Part 4: Autoclaved Autoclaved aerated concrete masonry units.
| Class of dry gross density | Range of dry gross density [kg/m3] |
| 300 | od 250 do 300 |
| 350 | > 300 i ≤ 350 |
| 400 | > 350 i ≤ 400 |
| 450 | > 400 i ≤ 450 |
| 500 | > 450 i ≤ 500 |
| 550 | > 500 i ≤ 550 |
| 600 | > 550 i ≤ 600 |
| 650 | > 600 i ≤ 650 |
| 700 | > 650 i ≤ 700 |
| 750 | > 700 i ≤ 750 |
| 800 | > 750 i ≤ 800 |
| 900 | > 800 i ≤ 900 |
| 1000 | > 900 i ≤ 1000 |
