Preliminary Results from California Warm-Mix Asphalt Study

This paper describes the first phase of the California warm-mix asphalt study, in which a test track was constructed to compare performance, under accelerated pavement and associated laboratory performance testing, of a control mix, produced and constructed at conventional hot-mix asphalt temperatures, with three mixes produced with warm-mix additives, produced and compacted approximately 35°C lower than the control. Key findings include: Laboratory tests on the mixes immediately after production revealed that the warm mixes had lower specific gravities and higher air-void contents compared to the control. These results were not representative of measurements after test track construction. Adequate compaction can be achieved on warm-mixes at lower temperatures. Based on the results of Heavy Vehicle Simulator (HVS) testing, it is concluded that the use of any of the three warm-mix asphalt technologies tested will not significantly influence rutting performance. Laboratory moisture sensitivity testing indicated that all the mixes tested were potentially susceptible to moisture damage. There was, however, no significant difference in the level of moisture sensitivity between the control mix and mixes with additives. Laboratory fatigue testing indicated that the warm-mix technologies assessed will not influence fatigue performance. HVS and laboratory testing completed in this study phase have provided no results to date to suggest that warm-mix technologies should not be used in California projects or elsewhere in the USA with similar conditions. Final recommendations on the use of warm-mix technologies will only be made after further accelerated pavement and laboratory testing and pilot studies on in-service pavements have been completed.


  • English

Media Info

  • Media Type: DVD
  • Features: Figures; References; Tables;
  • Pagination: 19p
  • Monograph Title: TRB 89th Annual Meeting Compendium of Papers DVD

Subject/Index Terms

Filing Info

  • Accession Number: 01158072
  • Record Type: Publication
  • Report/Paper Numbers: 10-2601
  • Files: TRIS, TRB
  • Created Date: Jan 25 2010 11:15AM