Measuring the plasticity of clays: A review

Plasticity is the outstanding property of clay–water systems. It is the property a substance has when deformed
continuously under a finite force. When the force is removed or reduced, the shape is maintained.
Mineralogical composition, particle size distribution, organic substances and additives can affect the plasticity
of clays. Several measuring techniques and devices were proposed to determine the optimal water content in
a clay body required to allow this body to be plastically deformed by shaping. In this review, methods of
evaluating the plasticity of clay–water systems are presented. Despite the advance in the theory of the
plasticity and the methods of measurement, a common procedure for all types of materials does not exist. The
most important methods are those that simulate the conditions of real processing