DETERMINATION OF THE EFFECT OF ENVIRONMENTAL TEMPERATURES ON COMPACTION OF ASPHALTIC PAVEMENTS

A FIELD STUDY WAS CONDUCTED TO LEARN THE EFFECT OF AMBIENT TEMPERATURES AND CONDITIONS ON THE COOLING RATE FOR 0.2 FT. AND 0.4 FT. PLANT-MIX COURSES DURING THE LAYDOWN AND ROLLING PHASES OF ASPHALTIC CONCRETE PAVEMENT CONSTRUCTION. THERMOCOUPLES WERE PLACED IN THE TOP, MIDDLE AND BOTTOM OF THE PAVEMENT COURSE. TEMPERATURES WERE RECORDED AT FREQUENT INTERVALS BEGINNING WITH LAYDOWN AND CONTINUING UNTIL ALL ROLLING WAS COMPLETED. AIR AND BASE TEMPERATURES, CLOUD COVER AND WIND CONDITIONS WERE RECORDED. DENSITIES OF THE FINISHED PAVEMENT AFTER FINAL ROLLING WERE DETERMINED BY BOTH NUCLEAR METHODS AND BY CORES TAKEN AT TWO FOOT INTERVALS ACROSS THE LANE. AIR VOID MEASUREMENTS WERE MADE ON EACH CORE. A CORRELATION BETWEEN THE ROLLER COVERAGES, TEMPERATURES DURING ROLLING AND THE DENSITIES AND AIR VOIDS OBTAINED FROM TESTS ON THE CORES WAS MADE OF THE FINISHED PAVEMENT. RESULTS SHOWED THAT THE TEMPERATURE DROP WITHIN THE MIDDLE OF THE 0.2 FT. COURSE OF PLANT-MIX IS MORE RAPID THAN IN THE 0.4 FT. COURSE AND THE TEMPERATURES AT THE MIDDLE OF THE COURSE WERE CONSISTENTLY 5-15 DEGREES HOTTER THAT AT THE TOP. BREAKDOWN AND INTERMEDIATE ROLLING WAS COMPLETED ABOVE THE SPECIFIED TEMPERATURE OF 140F AND IN SOME INSTANCES MUCH HIGHER. THE 0.4 FT. COURSE PAVEMENT AVERAGED HIGHER DENSITIES AND LOWER AIR VOIDS THAN THE 0.2 FT. COURSE. THE DENSITY OF THE TOP, MIDDLE AND BOTTOM PORTION OF 0.4 FT. COURSE CORES CORRELATES WITH THE TEMPERATURES ACTUALLY MEASURED AT THESE LEVELS. THE RESEARCH CONFIRMS THAT AIR VOIDS, DENSITY AND ASPHALT FILM THICKNESS ARE IMPORTANT FACTORS IN DETERMINING THE DURABILITY OF ASPHALT PAVEMENT. THE TEMPERATURE OF THE MIXTURE, AIR AND BASE TEMPERATURE, WIND VELOCITY AND SOLAR RADIATION INFLUENCE THE RATE OF COOLING OF A MIXTURE PLACED ON A BASE. REDUCTION OF AIR VOID TO A MINIMUM (3-5%) IS ESSENTIAL TO SATISFACTORY PERFORMANCE.

  • Supplemental Notes:
    • Res Project NO 54, 88 PP, FIGS, TABS, 4 REF, 3 APP
  • Corporate Authors:

    Idaho Department of Highways

    P.O Box 7129
    Boise, ID  USA  83707
  • Authors:
    • Wortham, G R
    • Erickson, L F
  • Publication Date: 1970-7

Subject/Index Terms

Filing Info

  • Accession Number: 00215344
  • Record Type: Publication
  • Files: TRIS, STATEDOT
  • Created Date: Sep 28 1970 12:00AM