Sand is an example of which soil type?

• A. Cohesive soil
• B. Non Cohesive soil
• C. Plastic soil
• D. Elastic soil

Answer: (B)

The distinction between cohesive and non-cohesive soils is what this item tests. Sand grains are discrete and do not bond to one another under normal conditions, so the soil’s strength comes mainly from friction between grains rather than any chemical or electrostatic cohesion. That makes sand a non-cohesive, or cohesionless, soil.

Cohesive soils, like clay, have significant bonding between particles, giving them cohesion and often plastic behavior. Plastic soil refers to soils with the ability to deform without cracking (clays are highly plastic), while elastic soil describes how soils respond with reversible deformation at small strains, which isn’t a fundamental category for soil type.