Workability of hot mix asphalt

Details

• Creators:
  Gudimettla, Jagan M. ; Cooley, L. Allen ; Brown, E. Ray
• Subject/TRT Terms:
  • Hot mix asphalt
  • Binders
  • Asphalt additives
  • Asphalt mixtures
  • Polymer asphalt
  • Workability
  • Hot mix asphalt (HMA)
• Resource Type:
  Research Paper
• Geographical Coverage:
  United States
• Corporate Publisher:
  National Center for Asphalt Technology (U.S.)
• Abstract:
  Workability in the field can be defined as a property that describes the ease with which hot mix asphalt (HMA) can be placed, worked by hand and compacted. Use of polymer-modified binders has increase in the U.S. due to the resultant performance benefits. However, the workability of HMA incorporating these binders decreases significantly at given temperatures as the modifiers increase the viscosity of the binders. The primary objective of this study was to develop a laboratory device to measure the workability of HMA mixes that could identify the change in workability due to changes in mix characteristics. A device was successfully designed that uses a paddle in a sample of HMA. The torque required to keep the paddle rotating a constant speed is measured; workability is defined as the inverse of the torque required to rotate the paddle. There were numerous two- and three-way interactions that were significant, including the gradation shape, binder type, and nominal maximum aggregate size (NMAS). A preliminary attempt was made at utilizing workability data to determine optimum compaction temperature of HMA mixes; however, the results were inconclusive. References, appendix, 16 tables, 42 figures, 88 pages.
• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/16069/dot_16069_DS1.pdf
• File Type:
  [PDF - 1.13 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:c68d09051b40c14b201c74c133428a3e5cb4cb7abf312eeb6cd1f26f6c3bdd8ec913eb30724162f72dc28332534f252cad696c908c14e3ff1f0b7f03ba2cb43a