Why Thin Asphalt Overlays Are Recommended For Pavement Preservation
Asphalt overlay is a process that can be used to improve the condition of an asphalt surface. Thin overlays can be applied to extend the life of a road surface, and can also be used to correct minor surface defects. Many state DOTs have adopted a policy of overlaying roads in poor condition, rather than reconstructing them.
Approximately 10% of all roads are overlaid each year. And each process requires thin overlays for optimum preservation of asphalt pavements.
Read more as we’re going to talk about why thin asphalt overlays are recommended for pavement preservation in today’s blog post.
Use And Application
Thin asphalt overlays can be used for applying new protective surfaces over existing pavements when the old surface has become severely damaged or no longer meets road design standards.
Likewise, a thin overlay might be applied to extend the life of a road surface, or to correct minor surface defects. Many state DOTs have adopted the policy of over laying roads in poor condition, rather than reconstructing them.
In the United States, the American Association of State Highway and Transportation Officials (AASHTO) standards allow for thin asphalt overlay on concrete or bituminous pavements in order to restore surface characteristics that have been deteriorated by aging, heavy use, and/or poor maintenance.
Asphalt overlay can be applied in several ways:
A thin asphalt overlay is often the best way to avoid full-depth reconstruction of a deteriorated road. The process typically involves removing surface layers of aggregate or old pavement (if needed), applying an adhesive (for example, by spraying if a liquid adhesive is used), and applying a thin asphalt wearing course on the prepared surface. Often, a tack coat will be applied to ensure good bond of the new asphalt layer to the old or prepared road base.
In some cases, grooves are cut in order to enhance skid resistance. In others, microtexture may be restored through the use of aggregate or other additives in the top course, cutting grooves to create an artificial texture, or using a thin surface course with special aggregates to provide additional skid resistance.
Best Practices To Be Followed
There are several best practices that should be followed when paving an asphalt overlay:
- The surface should be cleaned and free of any debris or oil before the overlay is applied.
- A tack coat should be sprayed on to help the overlay stick to the old surface.
- The overlay should be mixed and put down quickly, before it has a chance to dry out.
- The surface should be rolled immediately after the overlay is put down, to help it settle into place.
- Shade grooves can be cut into the surface if necessary for increased skid resistance.
Why It’s The Best Process For Pavement Preservation Treatment
There are several reasons why thin overlays are often recommended for pavement preservation:
- Thin overlays can be applied quickly and relatively easily, without requiring a lot of expensive equipment or labor.
- They can be used to restore the surface characteristics of a road that have been damaged by aging, heavy use, or poor maintenance.
- They can extend the life of a road surface and can be used to correct minor surface defects.
- Many state DOTs have adopted the policy of using asphalt overlays instead of full-depth reconstruction because it is often more cost-effective in the long run.
- The use of thin overlays leaves more room for future repairs and reconstruction, as needed.
- A thin asphalt overlay can be used to repair small cracks in existing asphalt pavement, providing long-term durability and functional performance where it is most needed.
It’s also important to take note that the main disadvantage of using thin overlays is that they require a lot of skill on the part of the contractor who is doing the work, and they usually have to be done by a specialized crew and a lot of equipment and materials. So it’s recommended to hire a qualified paving contractor like Biondi Paving & Engineering to handle this project for you.