Question

why is it said that plasticity anf cohesion play an important role in the workability of a soil?

Answer 1

Plasticity is a soil property which enables a moist soil to change shape

on an applied force and retain this shape even when the force is withdrawn. Thus sandy soils are

considered as non-plastic and clayey soils as plastic. Cohesion, on the other hand, is a property

of the particles to stick to one another by cohesive force. Plastic soils are cohesive. Plasticity and

cohesion reflect the soil consistency and workability of the soils. Black soils are highly plastic

and highly cohesive making tillage operation difficult.