DC Asphalt Repair

Asphalt Overlay

Asphalt Overlay: Re-layering of new asphalt over existing asphalt, usually done at a thickness of 1 ½” of new asphalt. Some companies will overlay at a micro level – 1” or less. This is nor recommended as this procedure is a very thin layer and normally is a short-term repair. In the long run, overlaying asphalt does not last as long as re-construction. The best scenario for an Asphalt Overlay is when the asphalt condition is still in good shape and the client wants a new look. Generally, an asphalt overlay with good maintenance, that is the cleaning of any loose debris, rocks, and keeping sprinkler overspray to a minimum may last 10 to 12 years. In some instances – even longer. There are a few caveats to an asphalt overlay, all potholes or damaged asphalt areas must be repaired prior to the laying of the overlay. Owners need to be aware that you cannot “hide” the damage as it will immediately show through. Cracks larger than ¼” will show through the asphalt overlay within a short time. The existing height levels will

Asphalt Re-Construction

Asphalt Re-Construction involves the complete removal of existing asphalt down to the base course. This option is highly recommended when the current condition is beyond repair – for example, there is more repair to do than areas that are in good shape. The steps involved to achieve a well done asphalt re-construction the following steps should be followed:

• The first step is to remove all of the existing asphalt down to the base course with either the use of a cold planer or tearing it out in chunks.

  • Cold planers definitely make for a better efficient job. They make a recyclable product (RAP) that can be re-used for many purposes such as base course or put back into asphalt during production – most asphalt products made today has anywhere from 18 to 20% RAP in it. Not many smaller paving contractors own a cold planer due to their high point of entry for cost.

  • Chunks tend to be cumbersome and difficult to get rid of. In addition, it takes more trucks to move the material – it does not load as tightly as RAP from a cold planer.

• Once down to the base course, the contractor needs to assess the base course – sometimes new base courses need to be added, or areas such as soft spots with mud need to be removed and replaced with class base needed

• Next re-grade and compacted with heavy roller

• Now the contractor is ready to pave. The industry standard for new asphalt is a minimum of 2” thick – sometimes you will encounter the project requires 3”

Asphalt Overlay

Asphalt Overlay is the process of placing new asphalt over existing asphalt. We normally only suggest this method when the existing asphalt is in decent shape – no heavy cracking or deterioration of binder. The steps to achieve a good overlay are as follows:

• Clean and prep the area to be over-layed by thoroughly cleaning the area with sweeping, with power blowers and brooms free of all debris such as rocks, dirt, leaves, etc.

• Apply a uniform coat of SS-1H tack coat – this will ensure proper adhesion of the new mat. This is a must!! Many below standard contractors try to fool people by not doing this or by using seal coat instead of SS-1H tack coat.

• Pave the overlay asphalt material at 1 ½” thick or greater. Important note: many contractors will try to pave at 1” sometimes even less – this is not recommended. Use fine State Mix 5 or City & County mix 4 and apply it when the material is still hot.

• Finally – compact with only the correct equipment and achieve the maximum compaction – 95% or greater.

The minimum thickness we recommend for overlay is 1 ½” thick – at this thickness the product turns out to have the ability to last much longer than the micro overlays some companies perform. Although this process sounds simple and an easy answer to new asphalt, it has issues that need to be discussed:

• If there is existing damaged asphalt, such as potholes or alligatoring – these areas will need to be cut-out and repaired prior to the overlay. Normally, there is a base failure and it also needs to be corrected as well.

  • In the event, these areas are not corrected, they will fail again very shortly after the overlay and reflect right through the new mat.

• The original height of the surface will be raised. Sometimes this causes trouble with grades that were originally set for water to move out of the lot or area and now it ends up not moving out. Also, it can cause trouble for gates and doors not closing correctly.

• If there is heavy cracking in the asphalt – it needs to be corrected prior to overlay otherwise these cracks will reflect through the new mat in a short time.