Full Depth Reclamation With Thin Surface Treatment for Low Volume Road Maintenance

About the report:

The Virginia Department of Transportation (VDOT) maintains more than 100,500 lane-miles of pavement on the secondary network.  Of this total, more than 95% of the lane-miles have an annual average daily traffic of less than 3,500 vehicles.  Pavement recycling techniques(such as full depth reclamation [FDR] and cold in-place recycling) can be used to fix many underlying issues in an existing pavement and when combined with thin surfacings, where appropriate, can help VDOT maintain low volume roads and provide significant cost and environmental savings.  However, VDOT has limited experience using pavement recycling techniques (especially FDR) where pavement is overlaid with thin surfacings.  The purpose of this study was to document the performance baseline for a series of FDR sections having thin surfacings on lower volume traffic routes since the performance of these types of pavements was previously unknown.  This study summarized the construction and initial performance of the FDR field projects on Rte. 602 in Surry County in VDOT’s Hampton Roads District and at Estates at Leeland in Spotsylvania County in VDOT’s Fredericksburg District; in addition, an inventory was conducted and the performance of past VDOT FDR projects on lower traffic routes was evaluated.

The study found that the initial performance of the FDR project on Rte. 602 (having three thin surfacing treatments) and the FDR project at Estates at Leeland (having a 2-in asphalt concrete surface) was promising at early ages.  However, the information gathered to date is not sufficient to make conclusions about the long-term performance of FDR with thin surfacings.  In general, for the past FDR projects reviewed, based on visual surveys and data from VDOT’s Pavement Management System, FDR with 2 to 4 in of asphalt concrete surface performed well at ages of 7 to 13 years after construction.

The study recommends continued performance assessment of the FDR sites surveyed in this study and additional field trials on the secondary network system using FDR with thin surfacings.  Further research is also recommended to develop a framework to consider using performance data from VDOT’s Pavement Management System to predict the future conditions of pavement sections on the secondary network.  Being able to identify those sections that could benefit from FDR treatments in the future would allow VDOT to allocate funding proactively for those sections based on early findings from this study.

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