What is plasticity index of soil?

The plasticity index of soil is a measure of the range of moisture content over which the soil exhibits plastic behavior. It is calculated as the difference between the liquid limit and the plastic limit of the soil. Soils with a higher plasticity index are more likely to exhibit plastic behavior and can be more easily molded or shaped when wet.

The plasticity index (PI) of soil is a measure of its plasticity, which is the ability of a soil to undergo permanent deformation in response to changes in moisture content. It is the difference between the liquid limit and the plastic limit.

PI = Liquid Limit - Plastic Limit

The plasticity index is an important index property of soil as it indicates the potential for a soil to exhibit plastic behavior, which can affect its performance as a construction material. Soils with a high plasticity index can be difficult to work with and may be more susceptible to shrinkage and swelling.