Specific weight of expanded clay: 1 m³ weight and density
Expanded clay is now one of the main components used to make lightweight concrete. This is because this type of material improves thermal insulation and increases the durability of concrete. However, constructing high-quality and reliable structures requires accurate calculations. This cannot be done without analyzing the characteristics of building materials. Therefore, to prepare the mix correctly, it is extremely important to know the weight of expanded clay accurately.
In construction calculations, the specific weight of expanded clay usually means the bulk weight of 1 m³ of material, that is, the mass of the fill together with the voids between the granules. This value depends on several characteristics:
- Expanded clay grain size. The specific weight of expanded clay changes depending on the fraction size: the larger the grains, the lower the specific weight. This can be seen using expanded clay of density grade M600 as an example in Table 1.
| Type of expanded clay | Specific weight (g/cm³) | Weight of expanded clay in 1 m³ (kg) |
| Fraction 0 - 5 mm, expanded clay sand | 0.55 - 0.6 | 550 - 600 |
| Fraction 5 - 10 mm | 0.4 - 0.45 | 400 - 450 |
| Fraction 10 - 20 mm | 0.35 - 0.4 | 350 - 400 |
| Fraction 20 - 40 mm | 0.25 - 0.35 | 250 - 350 |
Table of the weight of a cubic meter of expanded clay depending on its density.
- Density grade. Depending on the density grade according to the standard, the specific weight of 1 m³ of expanded clay also differs: the higher the density of expanded clay, the greater the total weight of the material. This can be traced, and the approximate weight of a bag of expanded clay by density grade can also be found, in Table 2.
- Expanded clay density. Denser grades will have a higher specific weight than less strong expanded clay because of lower porosity. The standard also establishes different strength grades. Table 3 helps with calculations by strength, as well as the bag weight.
| Density grade / strength grade | Specific weight (g/cm³) | Weight of a bag of expanded clay (42 l) |
| M250 / P-25 | 0.2 - 0.25 | 8.4 - 10.5 |
| M300 / P-30, P-50 | 0.25 - 0.3 | 10.5 - 12.6 |
| M350 / P-50 | 0.3 - 0.35 | 12.6 - 14.7 |
| M400 / P-50 | 0.35 - 0.4 | 14.7 - 16.8 |
| M450 / P-75, P-100 | 0.4 - 0.45 | 16.8 - 18.9 |
| M500 / P-100, P-125 | 0.45 - 0.5 | 18.9 - 21 |
| M600 / P-125, P-150 | 0.5 - 0.6 | 21 - 25.2 |
| M700 / P-150, P-200 | 0.6 - 0.7 | 25.2 - 29.4 |
| M800 / P-200 | 0.7 - 0.8 | 29.4 - 33.6 |
| M900 / P-200 | 0.8 - 0.9 | 33.6 - 37.8 |
| M1000 / P-200 | 0.9 - 1 | 37.8 - 42 |
| M1100 / P-200 | 1 - 1.1 | 42 - 46.2 |
| M1200 / P-200 | 1.1 - 1.2 | 46.2 - 50.4 |
Average values of the specific weight of expanded clay depending on its grade.
From the above, it follows that determining the exact specific weight of 1 m³ of expanded clay is practically impossible: too much depends on the exact characteristics of the material.
However, it is quite easy to establish an average value. The average figure for expanded clay in general is 400 kg/m³ or 0.4 g/cm³, and the bag weight is about 16.8 kg. When calculating numerical indicators for each fraction, a table of certain values can be compiled:
- Expanded clay fraction 0 - 5 mm — about 600 kg/m³ or 0.6 t/m³.
- Expanded clay fraction 5 - 10 mm — about 450 kg/m³ or 0.45 t/m³.
- Expanded clay fraction 10 - 20 mm — about 400 kg/m³ or 0.4 t/m³.
- Expanded clay fraction 20 - 40 mm — about 350 kg/m³ or 0.35 t/m³.
However, these figures are purely approximate and are calculated without taking the density grade and strength into account. They do not provide an exact value for determining the amount of material, but they do give a general idea of the weight.
See also:
- application area of expanded clay
Frequently Asked Questions
How much does 1 m³ of expanded clay weigh?
The weight of 1 m³ of expanded clay depends on the fraction and density grade. The article lists values from 250-350 kg/m³ for the 20-40 mm fraction to 550-600 kg/m³ for 0-5 mm expanded clay sand.
Why is coarse expanded clay lighter than fine expanded clay?
Coarser fractions have more voids between the granules, so their bulk density and cubic metre weight are usually lower. That is why the 20-40 mm fraction is lighter than 0-5 mm expanded clay sand.
How much does a 42 litre bag of expanded clay weigh?
The weight of a 42 litre bag depends on the density grade: for example, M400 is about 14.7-16.8 kg, while M600 is about 21-25.2 kg.