Warm Mix Asphalt

AUTC project number: 207086

PI(s):

Juanyu (Jenny) Liu (UAF)

Funding:
  • US Department of Transportation (RITA)
  • Permafrost Technology Foundation
  • Start Date: Jul 1, 2008
  • End Date: Apr 30, 2010

Project Summary

Field practices and studies including an on-going NCHRP and other state research projects showed that using warm mix asphalt (WMA) can reduce the high mixing temperatures of regular hot mix asphalt (HMA), increase the temperature gap between production and cessation (allowing increased haul distances), and decrease the binder viscosity allowing effective compaction, which is beneficial for stiff mixes, paving during extreme weather conditions and reduction in compaction effort.However, previous research has not focused much on how WMA functions in cold weather paving and the performance of the WMA in cold regions. In line with the WMA demonstration project to be conducted in Southeast Alaska, this study will focus on evaluating performance of WMA binders and mixes in cold weather conditions. How properties of original binder change with the addition of the Sasobit wax, and the correlation between the content of the Sasobit additive and the Superpave Performance Grade (PG) and binder stiffness will be assessed.The engineering properties of control and WMA mixes will be investigated in the laboratory as well including low temperature performance (by TSRST), rutting potential (by Georgia Loaded-Wheel Tester), dynamic modulus (by Simple Performance Tester) and moisture sensitivity (according to ASTM D 4867). The research findings will provide recommendations to determine the suitability of WMA technology for Alaskan conditions.