THE REPORT OF THE ROAD RESEARCH BOARD FOR 1957

VISCOSITY RANGES FOR BITUMEN FOR SURFACE TREATMENTS ARE LIMITED BY THE FACT THAT THE BINDER MUST BE SUFFICIENTLY FLUID TO WET THE CHIPPING AGGREGATES WHEN THEY ARE SPREAD ON AND ROLLED. HOWEVER, THEY ALSO MUST BE SUFFICIENTLY VISCOUS TO HOLD THE AGGREGATE IN PLACE AGAINST THE ACTION OF TRAFFIC WHEN THE BINDER HAS COOLED TO ROAD TEMPERATURE. IN THE EXPERIMENTS DESCRIBED, SOME FORTY SECTIONS COVERING 1 1/2 MILES OF ROAD WERE LAID IN THE SPRING, SUMMER, AND AUTUMN. THE VISCOSITY RANGE AND RATES OF SPREADING OF THE BITUMENS USED ARE GIVEN. IT WAS FOUND THAT FOR WORK IN THE SPRING AND AUTUMN, A CUTBACK BITUMEN SHOULD BE MORE FLUID THAN 200 SEC. AT 40 DEGREES C. WHILE FOR WORK IN SUMMER ON HEAVILY TRAVELLED ROADS, IT SHOULD BE MORE VISCOUS THAN 50 SEC. AT 40 DEGREES C. MEASUREMENTS ARE BEING MADE EVERY THREE MONTHS OF THE CHANGES IN VISCOSITY OF THE BITUMINOUS FILMS. THE USE OF HOT OR PRE-COATED AGGREGATES, IMPROVED THE WETTING OF THE CHIPS. HOWEVER, PRE-COATED AGGREGATES SHOULD BE USED IN MID- WINTER ONLY AS AN EMERGENCY MEASURE. /AUTHOR/

  • Corporate Authors:

    Road Research Laboratory /UK

    /Dept of Scientific & Industrial Res
    ,   United States 
  • Publication Date: 1957

Subject/Index Terms

Filing Info

  • Accession Number: 00210881
  • Record Type: Publication
  • Report/Paper Numbers: 57 pp
  • Files: TRIS
  • Created Date: May 6 1994 12:00AM