Today’s roadbuilding environment requires more results from fewer resources, so extending pavement life is critical. One way to do this is with concrete overlays.
Conventional thinking has concrete overlays most suited for high volume, heavy truckload pavements, such as intersections and interchanges. In fact, it’s been joked that intersection projects are the “gateway drug” for departments of transportation to adopt concrete overlays, primarily because the projects are relatively small and the results come quickly.
Concrete overlays have been used for more than 100 years, with more than 1,100 projects completed between 1901 and 2012, according to American Concrete Pavement Association figures. Projects have been completed in 45 states, and overlays make up 14 percent of the concrete paving market. In some regions of the country that figure represents more than half of the concrete pavements being placed.
The growing concrete overlay adoption rate can be attributed to two factors, according to Leif Wathne, ACPA vice president. One is a push by the association and its state chapters to educate transportation agencies about the efficacy of concrete overlays as a resurfacing option, a push that began roughly a decade ago. The other factor is price parity relative to other resurfacing options.
The specifications he references include the “Guide Specifications for Concrete Overlays” published this September by the National Concrete Pavement Technology Center (cptechcenter.org) at Iowa State University’s Institute for Transportation. The 32-page document offers guidance for developing specifications to meet the needs of overlay projects and covers details including the type of overlay to be used and the conditions in which they can be applied (see sidebar below).
