Originally Posted by HMXDave
I used 3/4 minus for all my driveways and RV pad...5 to 6" thick. The dirtier, the better (IE lots of the "minus" part). Very solid....had a cement truck in there for some backyard patio expansion and ZERO deflection or grooving.
The best is a well graded mixture. That is the large, medium and small size proportions are such that most if not all of the voids are filled between the top size. A small amount of clay would help bind the mixture. Stability is enhanced with the larger sizes have significant fracture (two more fractured faces on each particle).
Well graded quarried rock is the best IMO. We used 3/4- from a local gravel pit as it is all that is available in our area.