Clay is an example of which soil type?

• A. Non Cohesive
• B. Cohesive
• C. Plastic
• D. Granular

Answer: (B)

Soils are often described by whether the grains stick together (cohesion) or rely mainly on friction between grains. Clay is a fine-grained material whose particles bond to one another through electrochemical forces and moisture, giving the soil a noticeable cohesion. That interparticle cohesion means clay behaves as a cohesive soil, resisting shear as a mass. While clay can be highly plastic when wet—a property describing how it deforms—plasticity is a behavior of clay, not the basic soil type. Non-cohesive soils like sand or gravel don’t stick together and rely on friction, and granular is a term typically used for such non-cohesive materials. Therefore, clay is best described as cohesive.