Search results
Results from the WOW.Com Content Network
The amount of these minerals in a particular soil will also determine the severity of the shrink-swell capacity. [5] For instance, soils with a small amount of expansive clay minerals will not expand as much when exposed to moisture as a soil with a large amount of the same clay minerals. [5] If a soil is composed of at least 5 percent of these ...
The plasticity index is the size of the range of water contents where the soil exhibits plastic properties. The PI is the difference between the liquid and plastic limits (PI = LL-PL). Soils with a high PI tend to be clay, those with a lower PI tend to be silt, and those with a PI of 0 (non-plastic) tend to have little or no silt or clay.
Clay cannot be resolved by optical microscopes as its particles are 0.002 mm (7.9 × 10 −5 in) or less in diameter and a thickness of only 10 angstroms (10 −10 m). [ 16 ] [ 17 ] In medium-textured soils, clay is often washed downward through the soil profile (a process called eluviation ) and accumulates in the subsoil (a process called ...
Some clays used to make pottery do not require the addition of tempers. Pure kaolin clay does not require tempering. [6] Some clays are self-tempered, that is, naturally contain enough mica, sand, or sponge spicules that they do not require additional tempering.
Soils with high shrink–swell capacity, such as vertisols, recover quickly from compaction where moisture conditions are variable (dry spells shrink the soil, causing it to crack). But clays such as kaolinite , which do not crack as they dry, cannot recover from compaction on their own unless they host ground-dwelling animals such as ...
Grog, temper for clay. Grog, also known as firesand and chamotte, is a raw material usually made from crushed and ground potsherds, reintroduced into crude clay to temper it before making ceramic ware. It has a high percentage of silica and alumina. It is normally available as a powder or chippings, and is an important ingredient in Coade stone.
Expansive clay, also called expansive soil, is a clay soil prone to large volume changes (swelling and shrinking) directly related to changes in water content. [1] Soils with a high content of expansive minerals can form deep cracks in drier seasons or years; such soils are called vertisols .
The condition of a clay or clay body when it has been partially dried to the point where all shrinkage has stopped. Loss of Ignition The percentage of mass lost when a material is heated under specified conditions: 1,000 °C is common for ceramic raw materials Lustre