Pavement structure
Pavement structure
(OP)
I am working on a small parking lot which happens to be located on hard rock subgrade.
The owner wants it asphalt paved. Should I place the asphalt right on the bedrock, or should I place a layer of granular base first?
The owner wants it asphalt paved. Should I place the asphalt right on the bedrock, or should I place a layer of granular base first?





RE: Pavement structure
RE: Pavement structure
The part I am concerned with, is pretty high relative to the other parts of the site, any inches added in that area make the grading even more difficult then it already is.
We are in an area with freezing temperatures with lows down -20 celsius. How would it effect the asphalt placed on top of bedrock?
RE: Pavement structure
RE: Pavement structure
RE: Pavement structure
RE: Pavement structure
RE: Pavement structure
Dik
RE: Pavement structure
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: Pavement structure
Years ago, we had a contractor use a D-10 to excavate about 25,000 CY of unfractured basalt for a 2.5 million gallon reclaimed water tank in Southern California. The magic was a single ripper tooth on a hydraulic ram mounted to the back of the D-10. The ripper tooth was about 6" wide and the "point" had probably a 1/2" radius. The D-10 did the ripping and a D-9 moved the ripped material.
It worked like this....Stop the D-10 at an appropriate location; lower the ripper tooth until it contacts the rock; keep pushing with the ram until the ripper tooth lifts the back of the D-10 about 12"-18" in the air; wait maybe a minute or so until the weight of the D-10 forces the tooth into the rock and the D-10 settles back down on its tracks; then forward with 750 hp (?) to rip a furrow. Turn around and line up about 3' from the previous furrow, rinse and repeat. Over and over again. IIRC, a fully loaded D-10 weighs somewhere in the neighborhood of 90 tons.
One day I visited the site to check on the project. All work was stopped and our inspector was sitting there bored. I asked him what the situation was. He said "I'll show you" and walked me to the back of the D-10. The hydraulic ram was attached to the back of the D-10 with a 1-1/2" thick steel plate. Two weeks worth of cyclical stressing had torn the steel like it was a phone book.
BTW, the contract was set up for blasting, and I think the estimate for everything was about $350,000. This contractor was the only one to propose ripping. His bid was about 25% below our estimate and the 2nd low was only about 5% below. When he was done, he told our project manager that even with leaving so much on the table, he had made more money than he had planned.
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"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill
RE: Pavement structure