Kwan et al. [2] made the assumption that the shape of the
aggregates from one site, rock quarry, would be similar thus
it would be possible to estimate the mean thickness of the
particles in the sample. They presented a method of
estimating the thickness as a function of the breadth
multiplied by the area. An evaluation of Fig. 5 reveals that,
although there is a limited range in thickness values, they do
vary quite a bit thus their assumption [2] is too crude. It is
important to actually determine the thickness of particles
and not just estimate this property. It is a vital quality
governing how aggregates function in different engineering
materials and applications