Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Asphalt Concrete Thickness tied to Crack Resistance

Asphalt Concrete Thickness tied to Crack Resistance

Asphalt Concrete Thickness tied to Crack Resistance

Hello All,

The Caltrans highway design manual recommends a minimum thickness on road overlays to help resist cracking. Indeed the idea behind "superpave products" is to make a long lasting road by increasing the Asphalt Concrete section. What I am looking for are reference standards to support the idea that having a thicker asphalt concrete section and not necessarily a stronger structural section would better resist cracking. Any pointers?


RE: Asphalt Concrete Thickness tied to Crack Resistance

Overlays on top of an older pavement of asphaltic concrete over base course seems like wishful thinking to accomplish the goal of no cracks. That old pavement with its cracks will tend to move back and forth with temperature changes due to loss of ductility. The new layer on top will tend to follow that for a year or two, and not crack right away even if thick, depending on its ability to stretch over the cracks below. Seems like a given thickness of new and expect no cracks is unrealistic.

RE: Asphalt Concrete Thickness tied to Crack Resistance

Cracking in the asphalt (not weather related) is controlled by the lateral strain at the bottom of the asphalt layer. As you increase the thickness of the asphalt you mitigate the strain levels at the bottom of the layer. Since asphalt overlays are considered bonded overlays, the stresses and strains transfer through this interface unless there are existing cracks in the pavement prior to overlaying. To keep that transfer working we usually span the cracks with a supplemental grid of some type of fabric that is set in asphalt cement or we meticulously fill the cracks.

Rutting is controlled by vertical strain in the subgrade, which is why we need a competent subgrade and base for the pavement section.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


White Paper - PLM and ERP: Their Respective Roles in Modern Manufacturing
Leading manufacturers are aligning their people, processes, and tools from initial product ideation through to field service. They do so by providing access to product and enterprise data in the context of each person’s domain expertise. However, it can be complicated and costly to unite engineering with the factory and supply chain. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close