Characterization of two perpetual pavements at the NCAT Test Track

Two experimental asphalt pavement sections were built at the National Center for Asphalt Technology (NCAT) Test Track in 2003. Designed according to the 1993 AASHTO Design Guide, they were expected to fail after 10 million equivalent single ax e loads (ESALs). However, they performed well throughout the initial 10 million ESALs and have far exceeded their performance expectations with an additional 20 million ESALs applied with excellent performance during the past six years. Though designed as conventional pavements, these sections have performed effectively as perpetual pavements. The main objective of this investigation was to evaluate the long-term structural and performance characteristics of these unexpected perpetual pavements. The investigation included backcalculation of falling weight deflectometer data to monitor in situ asphalt concrete (AC) moduli versus time and traffic. It was found that the AC moduli increased approximately 12 to 20% during the past six years. Weekly monitoring of ride quality, mean texture depth and rutting have shown no appreciable change over time, indicative of a perpetual pavement. Though some minor cracking was observed after 30 million ESALs, forensic investigations indicated it was top-down which was also consistent with a perpetual pavement. Finally, endurance limits determined through laboratory beam fatigue testing were compared against pavement responses measured from embedded strain gauges. The measured strain levels in situ were significantly higher than the endurance limits, approximately double at the 90th percentile, which suggested the need to revise conventional approaches to perpetual pavement design.

Language

  • English

Media Info

  • Pagination: pp 513-521
  • Monograph Title: Bearing capacity of roads, railways and airfields: proceedings of the ninth International Conference on the Bearing Capacity of Roads, Railways and Airfields: Trondheim, Norway 25-27 June 2013. Vol 1-2

Subject/Index Terms

Filing Info

  • Accession Number: 01596549
  • Record Type: Publication
  • Source Agency: Swedish National Road and Transport Research Institute (VTI)
  • ISBN: 9788232102853
  • Files: ITRD, VTI
  • Created Date: Apr 21 2016 12:28PM