Asphalt or Concrete: Weighing Your Options
Asphalt overlay is a paving method of applying a new layer of asphalt to a deteriorating surface. Rather than tearing up an old asphalt surface entirely, an asphalt overlay project will use the existing layers as a base for the new asphalt pavement. Some asphalt surfaces with severe damage like rutting, potholes, large cracks, and expansions will need to be milled before an overlay is applied.
Asphalt Overlay Steps
Asphalt Assessment
Not all existing asphalt surfaces are suitable for asphalt overlay. If an asphalt surface has extensive structural damage such as large potholes, root damage, or ruts in the surface, it will need to be ripped up. Asphalt surfaces that are not draining water correctly may also not be suitable for asphalt overlay because the surface may need to be regraded to handle water more effectively.
Asphalt Milling
Asphalt milling will remove the top layer of an asphalt surface that has taken on cracks, raveling, or other damage. The old layer that has sustained damage must be removed to ensure an even bond when the new asphalt is applied, and to maintain a level surface. An asphalt milling machine will grind down 1″ to 3″ depending on the wear of the asphalt surface. The ground surface material will be hauled to an asphalt recycling plant where it can be integrated into new asphalt mix designs.
Base Repair
The base of an asphalt surface may need to be replaced in areas where potholes, rutting, and sinking have formed. In order to make sure a severe problem will not form again the base of the asphalt surface will be rebuilt using multiple lifts of aggregate and asphalt.
Pave Surface
Once the existing asphalt surface has been prepared, the asphalt overlay can be paved on top of the surface. The amount of asphalt overlay applied to the surface will vary depending on the thickness of the existing surface, but typically will be within 1.5″ to 2″ thick.
Asphalt Overlay on Concrete
In certain situations, asphalt overlay can be applied to a concrete paved surface. When a concrete surface deteriorates there is not an easy option to repave the surface with concrete without ripping the surface up entirely. Asphalt overlay is an option for some asphalt surfaces that are in disrepair, but paving asphalt over concrete comes with some catches.
Concrete paved surfaces are not compressed and compacted like asphalt is, rather the concrete adheres and fills voids and irregularities with the soil and subgrade beneath it. Because concrete is a harder surface that does not have as much give as asphalt, expansion joints are cut into the surface to help prevent cracking from seasonal expansion.
When you pave over concrete with asphalt, these expansion joints will cause the asphalt surface to shift over time potentially creating cracks and bumps. Cracks in the asphalt along expansion joints will not cause the surface to fail, but it will need to be crack sealed over time to maintain a water resistance.
Get Your Free On-site Asphalt Overlay Consultation!
Lone Star Paving offers a free on-site consultation where we will be able to assess the state of your surface and determine what needs to be done. Contact us today to schedule your free on-site consultation!
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