Flakiness index is a method which attempts to measures
how thin particles are compared to their sieve size in
general. The sample is sieved two times. First using sieves
with square apertures and then using bar sieves. The aperture
size of the sieves is dependent upon the size of the material.
The aperture of the bar sieve is half that of the square sieve
aperture size. The flakiness index is the ratio of the mass of
the material retained on the two sieves times 100 and is
rounded off to the nearest whole number. The flakiness
index can be calculated for each fraction in the sample