As with anything, the asphalt and concrete surfaces of your roads and parking lots are sure to slowly deteriorate over time. Eventually this deterioration will result in severe enough damages that you will need to consider having your cement or asphalt structure repaired. This is where a method know as Asphalt Overlay comes into play.
The Basic Concept Behind Asphalt Overlay
True to its name, Asphalt Overlay, also sometimes referred to as Pavement Overlay or Asphalt Pavement Overlay is the application of heated asphalt over a pre-existing surface in order to create a new one. This is generally done when a paved surface has begun to deteriorate enough that spending money to have it repaired is justified, but it is still in good-enough condition that a full replacement job is not yet necessary. An overlay can also offer additional strength to a structure that a repair method like sealing will not.
Considering that on average a good Asphalt Overlay can last as long as 10-15 years, this method of repair may be highly desirous for many business or property owners as it is in most (not all) cases more affordable and more time efficient than ordering a full replacement job.
Beneath the Surface
The type of repair job necessary not only depends on the severity of the damage to a structure but also the type of material that makes up the base or foundation of the surface.
If the road or parking lot is paved with concrete instead of asphalt its base may be constructed of separate or jointed Portland Cement Concrete (PCC) slabs. These must be broken down or rubblized to form a suitable base for the Asphalt Overlay. Otherwise, the slabs beneath the surface will eventually shift and cause new cracks to appear. Other methods usually involve applying a surface layer of PCC slabs on top of a similarly constructed base, these surfaces are known as PCC Pavements.
Mill and Overlay
In some cases, the asphalt or pavement surface is damaged on more than a superficial level and the base of the structure is beginning to deteriorate. In this case, the surface of that structure may need to be milled before the actual overlay itself can be applied. Milling is the process of grinding up the top 1-½ to 2 inches of asphalt with a Milling Machine, also known as a Cold Planer, to remove structural imperfections such as shallow cracks and potholes. As a result, this creates a more suitable base.
The ground up surface is then recycled and mixed in with the rest of the heated asphalt that will be used to create the overlay, making the process more resource efficient and environmentally friendly as it lessens the amount of fresh asphalt that will need to be created to complete the project.
Finally, the heated asphalt or Hot Mix Asphalt (HMA) itself will be applied to the structure and properly paved over to create your road or parking lot’s new surface. Usually this new surface is anywhere between 1.5 to 2.0-inch (37.5-50mm) thick. If it is a thin overlay it may be closer to 0.5in or 12.5mm thick.
Time efficiency is key when completing a project on a busy roadway or parking lot, after all there’s only so long you can feasibly close it down. Luckily, even after taking milling into account, asphalt overlay projects may take as little as 1 or 2 days to complete.
Asphalt Overlay by Kleenco Construction
Asphalt overlay stands as a solid middle ground option for moderate levels of deterioration. Unsure what the best route to recovery is for your paved structure? We are here to help! Contact us today to get a project estimate to help you reach a final decision.