Asphalt overlay over existing asphalt and concrete pavement?

[hbogyt]

I must be grasping at straws here. I need to save my client some money by using as much overlay as possible, over a car park. The existing pavement has an area where both concrete and asphalt exists (used to be an underground LPG tank there under a huge concrete slab. They excavated the LPG tank by cutting the concrete and reinstated asphalt pavement.)

My question is, is there a method that allows me to adequately control reflective cracking resulting from overlaying over rigid + flexible pavement.

Cheers.

 

[Ron]

Not completely. You can use Geogrid or similar to mitigate the reflective cracking, but some will likely occur and must be maintained. When the first cracks do appear, if they are sealed quickly, it will take a lot longer for them to reappear.

 

[MotorCity]

In some cases, existing pavement is intentionally broken into small sections (say 1' to 2') using a falling weight mounted on the back of a truck. Part of the idea is that by breaking it into smaller sections, you don't get reflective cracking due to large sections of pavement rotating or deforming under load. The other thing it does is seat the small broken sections firmly into the subbase.