Microsurfacing: Paving The Road Ahead

A Cost Effective Approach To Pavement Management

Dover -- The Delaware Department of Transportation (DelDOT) informs motorists about the use of a new process known as microsurfacing, which is becoming a popular alternative to traditional hot-mix asphalt.

Microsurfacing is a thin, tough layer of asphalt emulsion containing aggregate (rocks), water and mineral fillers. It is used to seal cracks and prevent moisture from penetrating the road base. It is primarily used for preservation of the materials in existing hot-mix roadways, which is important as transportation officials look for cost-effective ways to stretch their pavement funding.

It is often most effective when the existing hot-mix surface is 5-7 years old and showing minimal signs of distress. Residents may wonder why a road is being rehabilitated when it appears to be in good condition, but this is the ideal time to do a preservation technique that will further extend the life of the underlying pavement and decrease the long-term maintenance cost of the roadway. If the roadway does exhibit signs of distress, patching and crack-sealing will be done prior to application of the microsurfacing materials.

Microsurfacing is being used on several roads throughout Delaware and provides a smoother road surface, a quieter ride and less loose material than traditional surface treatment (a.k.a tar and chip). When a road is first microsurfaced, it may present an initial rougher driver surface. This somewhat abrasive surface creates a more skid-resistant surface, thus increasing the safety of the road itself. However, as cars travel over the road, the stones and materials become compressed and smoother, ultimately resulting in a road surface that is nearly as smooth as traditional asphalt hot-mix overlay, but still course enough to prevent skidding.

"Motorists can equate microsurfacing to sealcoating a paved driveway. It's a form of maintenance that can be done periodically to preserve the original asphalt at a lower cost," says Jennifer Pinkerton, DelDOT's Pavement and Rehabilitation Program Manager.

The microsurfacing material is also being used to patch rutted roadways like those in the West Dover area. The material creates a smoother surface on the road without the complexities and cost of a full-scale pavement rehabilitation project. In addition, this material can be used during nighttime hours, and on roads with high traffic volumes. It can also be applied anytime during the year as it is not as temperature-sensitive. This lengthens the traditional summer paving season.