Let me "splain" it to you Lucy...
At 55 yards long the asphalt driveway slopes a bit from the garage out to the street. I leveled the grade on the pad to match that slope. The top of the asphalt coincides with the top of the ties. I dropped 4,000+# of crushed granite into the pad varying between 4 - 6" deep and then aggressively compacted it alternating between soaking it down and driving over it repeatedly with my Rzr and then the truck.
After three days the surface was extremely firm. I then carved a 2" deep trench along the ties and the asphalt and filled that as well as the rest of the pad with the top layer of the larger concrete gravel {another 2,000#}. Once again I soaked it all down and compacted it further using my truck. The second pic shows this clearly, the asphalt, gravel and ties are all the same height {mas y menos} and the compacted top layer of gravel will remain in place.
Absent the ties that secure the pad and provide the requisite structure the gravel would be displaced and scattered across the asphalt every time it was driven on. Containing the gravel is the key... After 8 months the pad where I park the coach {which weighs 11,500#} is working out just fine with no gravel movement and great drainage which Lucy, is why I utilized the same construction technique for both pads.
Here is a pic of the coach pad and as noted you can see that the gravel stays put:
:C
