Buried Treasure: Uncovering Concrete Pavement for Extended Performance and Enhanced Sustainability

Many agencies employ asphalt overlays as a patterned response to the loss of serviceability in concrete pavements, regardless of the types and extent of deterioration or the structural condition of the pavement. In many cases, the underlying concrete pavement may have been a good candidate for the application of pavement preservation treatments to restore functionality. However, even though a concrete pavement has received an asphalt overlay, there may still be opportunities to implement a concrete pavement preservation solution provided that the overlay was placed for functional reasons and that the underlying concrete pavement is structurally sound and in relatively good condition. This “buried treasure” approach offers a number of benefits, including reduced costs, improved performance and longevity, and reduced environmental impacts. The strategy has been used successfully by a number of state highway agencies throughout the U.S. This paper presents several case studies in which an existing asphalt overlay was removed, and the underlying concrete pavement restored using concrete pavement preservation treatments. Featured projects include Highway 21 near Newark, NJ; U.S. 20 near Blairsburg, IA; and SR 202 in Phoenix, AZ. A number of lessons learned from these case studies are presented, including guidance on determining the suitability of an existing overlaid concrete pavement for preservation, detailed processes and considerations for the effective removal of the existing asphalt overlay to minimize damage to the concrete pavement, and guidelines for the successful application of preservation treatments such as slab stabilization, full- and partial-depth repairs, dowel bar retrofit, and diamond grinding.