Evaluation of Enhanced-Friction Asphalt Overlays and Surface Treatments

Details

• Creators:
  Moore, Nathan ; Heitzman, Michael ; Musselman, Jim ; Powell, Buzz
• Corporate Creators:
  Auburn University. National Center for Asphalt Technology
• Corporate Contributors:
  Florida. Department of Transportation
• Subject/TRT Terms:
  Aggregates Alternative Aggregates Benefit Cost Analysis Crash Locations Friction High Friction Surface Treatment Open Graded Aggregates Surface Treating Testing Wet Weather
• Publication/ Report Number:
  BED59
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Florida
• Edition:
  Final Report: April 2022 – June 2024
• Corporate Publisher:
  Florida. Department of Transportation
• Abstract:
  Highway agencies are responsible for maintaining pavements with good surface friction performance. High crash locations are often treated with a high friction surface treatment that has very good friction performance but has a high cost. This study examined asphalt surface mixtures with alternative friction aggregates using accelerated laboratory Three-Wheel Polishing Device (TWPD) polishing and Dynamic Friction Tester (DFT) testing as options for High Friction Surface Treatment (HFST). A chip seal with alternative friction aggregate failed to survive conditioning with the TWPD. Standard FDOT 9.5 mm, 4.75 mm, and OGFC mixes with granite and limestone were modified with high and moderate amounts of three alternative friction aggregates (calcined bauxite, quartzite, and slag). Developing equivalent gradation blends required the use of volumetric proportioning to account for differences in aggregate specific gravities. Friction test results showed that some aggregate combinations with slag and calcined bauxite demonstrated improve friction performance. A cost-benefit analysis examined the cost per year of service and the potential crash rate reduction. Studies of crash rate versus pavement friction do not have sufficient friction data beyond conventional asphalt surface mixes, so extrapolated curves were used to estimate the safety impact of HFST. None of the alternative asphalt mixtures demonstrated comparable friction performance to a HFST. However, a number of alternative asphalt friction mixtures showed moderate reductions in crash rate while maintaining a low cost per year of service. Low cost and moderate improvements in safety could make these alternative mixtures a viable option for some crash locations.
• Format:
  PDF
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:ff2a537717f626a9794c0f7a912f0eb8361ff8c3cd92c5f0f2562f16f7a3ddd067aeb4adca951c12a4be9e7047761ecdb748fb4b16e91db7393223948d6b5a99
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/88423/dot_88423_DS1.pdf
• File Type:
  [PDF - 6.46 MB ]