Specific and volumetric weight of different types of clay

Clay is used quite widely in construction. It is a soft, plastic and fine-grained rock used for mortars, stove masonry, brick production, ceramics and other materials. Clay occurs in many soil types and acts as a binding component for fine and coarse mineral particles.

When clay is used in construction and production work, its weight often needs to be known. The mass of the material depends on clay type, moisture, density, mineral composition and impurities.

The specific weight of clay is usually understood as the ratio of material mass to occupied volume. This value varies noticeably depending on the clay type and composition. Common types of clay include:

1. Refractory clay is a dense mass of blue, yellow, white or grayish color. It contains a significant amount of alumina and silica, is used for refractory products and usually has a high specific weight.
2. Fuller's clay is a material containing magnesian compounds and capable of absorbing fats and oils. It often has a gray-green or olive shade and an average specific weight.
3. Common, or potter's, clay is a dry and hard mass that becomes viscous and dough-like when moistened. It may have a high specific weight.
4. Saline clay is a clay mass with salts and gypsum impurities. It usually has an average specific weight.
5. Alum clay is a dark material that can change properties during weathering. It has average specific weight values.
6. Resinous clay is a brown, yellow or dark-brown material containing iron compounds and other impurities. It belongs to denser clay types.
7. Lime-containing clay has average specific weight values that depend on the share of lime inclusions.

Table of the weight of 1 m³ of clay depending on type

To estimate the weight of 1 m³ of clay, in most cases it is enough to know the material type. The table below gives the specific weight of clay and the approximate number of kilograms in one cubic meter.

Which clay weight to use for transport and earthworks

Values of 2.4 - 2.65 g/cm³ refer to dense mineral material and particular clay types. For delivery, soil removal and preliminary truck-load calculations, bulk or volumetric density is usually more useful; it is lower and depends strongly on moisture and compaction.

For simple delivery estimates, an average value of about 1600 - 1900 kg/m³ is often used. If the clay is wet, mixed with stones or heavily compacted, the actual cubic meter weight can be noticeably higher.