This chapter deals with the issues related to packing of particles in nature –
aggregate in the first place - and in cementitious materials. Many of these topics are
extensively discussed in the international literature, so will only be briefly introduced,
while additionally giving a restricted number of references. Relatively new
developments, such as producing the realcrete by computer, yielding compucrete, will
receive more explicit attention. The way to do this properly by DEM (discrete element
method) instead of by popular RSA (random sequential addition) is stressed. Modern
dynamic DEM renders possible simulating aggregate of fluvial origin as well as of
crushed rock. Similarity of simulating particle packing on mesolevel (aggregate) and
on microlevel (binder) was the argument to sketch modern developments in the latter
field, because they provide information on permeability and are thus of paramount
important for sustainability. A phenomenon recently receiving attention in the literature
is Brazil Nut Effect. It is a part of nature and it can significantly influence the
compacted particle structure of aggregate or binder alike. Some relevant information as
to cementitious materials will be provided.
Keywords: Aggregate, binder, concrete, discrete element method, particle
packing.
