What's a generic overlay pavement design. 1

[hbogyt]

so I'm raising the surface by 0 - 200mm over a large area. Using all asphalt is too expensive, do you think I can just chip off a layer of existing asphalt, throw some crushed rocks on top, then put new asphalt down? I'm asking because I seem to recall that crushed rock only goes beneath asphalt but not on top, and that to add more rocks, you need to remove all the existing asphalt. Is this correct?

 

[geomane]

Depends on where you are, what the pavements are for, what the ESAL's are, design life, etc.

 

[Ron]

I would not install aggregate as a sandwich between two layers of asphalt. You will likely have shoving issues.

This is a good candidate for mix-in-place recycling where the existing asphalt is pulverized and mixed with some depth of base material. Supplemental aggregate can be placed before or after mixing, depending on your needed pavement structure. You can add emulsified asphalt during the mixing process to create a very competent pavement base material. Then pave with asphalt. I've used this process on miles and miles of pavement in the southeast US.