A method of estimating the form of fine particulates

In the companion paper we noted that a significant body of literature exists to suggest that form can have an important influence on the behaviour of an assembly of particles during shear, and that at present there are no practical methods of measuring form. A simple definition of form was adopted, and a method of measuring form was proposed for coarse particulates, and applied to a range of materials. This paper considers the form of fine particulate materials. It reviews the evolution of the size and shape of clastic and crushed rock particles, and examines the applicability of methods that have been developed in other fields for determining the form of fine particles. A new method of determining form, based on turbidity measurement and laser diffraction particle sizing, is proposed and applied to seven different materials with widely varying form.