U.S. Route 60 is the main thoroughfare into and out of Powhatan, Virginia, a town that lies just west of the busy capital of Richmond. Currently, this highway is a four-lane divided facility carrying 10,000 average daily traffic (ADT) with 35 percent truck traffic. When a 1.8 mile asphalt section of this heavily used facility was in need of major repair due to structural distress, the Virginia Department of Transportation (VDOT) chose full-depth reclamation (FDR) with cement for rehabilitation.
Distresses along U.S. Route 60 in Powhatan, Virginia
Slurry Pavers, Inc., a seasoned roadway stabilization and reclamation contractor from Glen Allen, Virginia, was chosen to perform the U.S. Route 60 reclamation work. VDOT chose to not only use full-depth reclamation along the existing four-lane section, but also to widen the four-lane section by an additional four feet on the outside shoulder and two feet on the inside shoulder. In choosing the pavement section, VDOT used a 0.32 layer coefficient following the American Association of State Highway and Transportation Officials (AASHTO) design methodology with a 20-year design life. The resulting typical section was 12 inches of FDR with cement, 2.5 inches of intermediate (binder) asphalt course, and 1.5 inches of asphalt surfacing (wearing course).
Pulverized section along U.S. Route 60 ready for cement
The in-situ pavement section consisted of 4 to 6 inches of asphalt underlain by 6 to 8 inches of graded aggregate. The mixture design required 5 percent portland cement by dry weight of the in-situ materials in order to obtain the specified minimum 7-day unconfined compressive strength of 250 pounds per square inch (psi). Each lane was closed for 24 hours while Slurry Pavers performed the FDR work and upon each day’s completion, a chip seal was placed on the freshly finished section to accommodate the release of traffic on the newly laid base.
Full-depth reclamation operations were completed in two weeks with no failures reported. U.S. Route 60 is an excellent example that FDR with cement is not just for rural roads but multi-lane and high traffic facilities can also benefit from this technology.