[walter]

I think both Larry and Walter have mentioned aggregates that "look good" from the way they are tightly packed.
However, I think that when you look at a mixture, the eye will concentrate on the distribution of the biggest particles, and the rest will tend to merge into a simple background mass.

Here's the picture of a "good looking" mix (from compaction standpoint).

Mix on the left looks random and not very exciting, but when you press it forms incredibly solid void less block. The mixture was created purely by stirring and feeling how tightly it packs. Stirring the mix on the left is effortless, the one on the right- almost impossible. Once compacted it takes a lot of energy to bring it back to uncompacted state. That's my definition of a good mix.


Here's something about Zeeospheres..

You're all assuming that they are there for filling purposes. They're not. They create flow- most important property of your mix. They make things possible that otherwise wouldn't be. Their size/hardness is just an added bonus.
_