The Delaware Department of Transportation says motorists may encounter roads this summer season that have recently been paved using what is known as “microsurfacing,” as opposed to traditional asphalt.
DelDOT started using this paving technique a few years ago, as it is about one-fifth the cost of traditional 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 existing hotmix roadways as transportation officials look for cost-effective ways to stretch their pavement funding.
Typically, half a road is closed for microsurfacing at a time. The length of time the road is closed depends on air temperature and humidity, and whether one or two passes of microsurfacing is applied. Once this material is applied to the road, it needs to dry for approximately one hour before it is ready for traffic.