Warm mix technology: from innovation to implementation

The benefits of warm mix asphalt such as reduced energy consumption, lowered emissions, and elimination of visible smoke are well-known in the hot mix industry. Warm mix technology allows mix to be prepared and placed at lower temperatures than conventional hot mix. To achieve this, the viscosity of the bitumen must remain free flowing at the reduced temperatures. Maintaining a low viscosity at lower temperatures allows mix to flow freely through storage, transfer and placement equipment and also is more easily worked by hand. The current technologies for warm mix production rely on additives, special asphalt cement, special procedures and/or special asphalt concrete (AC) delivery systems to achieve low viscosities at low temperatures. The Astec multi-nozzle device eliminates the need for expensive additives and special asphalt cement by mixing a small amount of water and AC together to create microscopic bubbles. These small bubbles act to reduce the viscosity of the AC coating on the rock thereby allowing the mix to be handled and worked at lower temperature. The paper will review the evolution of Astec warm mix technology over the past 12 months and present laboratory and field test data of several field trails monitored by National Center for Asphalt Technology (NCAT) laboratory staff. (a) For the covering entry of this conference, please see ITRD abstract no. E216180.

  • Authors:
    • RENEGAR, G
  • Publication Date: 2007-10


  • English

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Filing Info

  • Accession Number: 01099886
  • Record Type: Publication
  • Source Agency: TRL
  • Files: ITRD, ATRI
  • Created Date: May 27 2008 8:56AM