ASPHALT CONCRETE PRODUCED BY THE DRYER-DRUM MIXING PROCESS

Due to the increasing popularity of the dryer-drum method of mixing asphalt concrete and the lack of information regarding the effect of mixing and laying hot mix at temperatures as low as 200F (93C) and moisture content as high as 3 percent, a study was initiated to evaluate, thru laboratory testing and field performance, the quality of AC mixed in a dryer-drum plant. From 1973 to 1975, four California Department of Transportation projects were investigated to evaluate a dryer-drum (C.M.I.) mixer. The results from this study clearly showed that the C.M.I. dryer-drum plant studied could provide satisfactory asphalt content and aggregate gradation uniformity. The asphalt concrete was uniformly mixed and no problems were encountered during the spreading and compaction operations. The C.M.I. dryer-drum plant had problems meeting County emission standards even after pollution control devices were used in conjunction with a cyclone dust collector. Periodic condition surveys were made since these projects were completed. The performance of the pavements to date is considered good. Even though some distress has been noted, this distress cannot be attributed to the mixing process used.

• Corporate Authors:

  California Department of Transportation

  Transportation Laboratory
  5900 Folsom Boulevard
  Sacramento, CA  United States  95819

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Cechetini, J A
  • Doty, R N
• Publication Date: 1977-6

Media Info

• Pagination: 44 p.

Subject/Index Terms

• TRT Terms: Aggregate gradation; Aggregates; Asphalt; Asphalt concrete; Asphalt content; Dryer drum process; Dust; Laboratory tests; Mixing plants; Moisture content; Pavement performance; Performance; Pollutants; Service life
• Uncontrolled Terms: Field performance
• Geographic Terms: California
• Old TRIS Terms: Drums chemical engineering; Drying apparatus
• Subject Areas: Design; Geotechnology; Highways; Materials;

Filing Info

• Accession Number: 00169759
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: FHWA-CA-TL3125-77-09Final Rpt., 633125
• Files: NTIS, TRIS, USDOT, STATEDOT
• Created Date: Mar 14 1978 12:00AM