Research

Brian K. Diefenderfer and Alex K. Apeagyei, Virginia Transportation Research Council

During the 2011 construction season, the Virginia Department of Transportation (VDOT) completed an in-place pavement recycling project to rehabilitate a 3.66-mile section of pavement on I-81 near Staunton, Virginia. VDOT employed three in-place pavement recycling techniques, full-depth reclamation (FDR), cold in-place recycling (CIR), and cold central-plant recycling (CCPR). Materials for both the CIR and CCPR were produced using foamed asphalt with cement as an additive. A combination of cement and lime kiln dust was chosen for the FDR process.

 From the results of this study, the combined structural layer coefficient for the CCPR and FDR materials was calculated as 0.37. The structural layer coefficient for the CIR material was calculated as 0.39. The structural layer coefficient for the CCPR material was calculated to have a likely range of 0.37 to 0.44. Laboratory testing showed that the performance of the CCPR and CIR materials is expected to be similar. The field performance tests demonstrated that the section of pavement rehabilitated by the three in-place recycling methods continues to perform well after nearly 3 years of high-volume interstate traffic.

Virginia Center for Transportation Innovation and Research, Report No. FHWA/VCTIR 15-1R, Charlottesville, VA.