SPECIFICATIONS FOR DENSITY CONTROL OF ASPHALT PAVEMENTS

A BRIEF REVIEW IS PRESENTED OF THE SPECIFICATIONS FOR THE COMPACTION OF ASPHALT PAVEMENTS. THE END RESULTS AND METHOD TYPE SPECIFICATIONS ARE DISCUSSED, AS WELL AS THE NONDESTRUCTIVE METHODS OF DETERMINING RELATIVE DENSITY AND THEIR POTENTIAL FOR BETTER SPECIFICATIONS. THE PROPER PROVISIONS FOR SUITABLE AGGREGATES, ASPHALT, MIXING, AND SPREADING ARE IMPORTANT AND BEAR ON GOOD COMPACTION RESULTS. ANOTHER IMPORTANT PREREQUISITE IS A FIRM, STABLE, AND WELL- COMPACTED BASE ON WHICH TO PLACE THE ASPHALT CONCRETE. THE FOLLOWING TWO CONVENTIONAL METHODS USED FOR CONTROLLING COMPACTION OF ASPHALT CONCRETE PAVEMENTS ARE DISCUSSED: (1) A RELATIVE COMPACTION REQUIREMENT, AND (2) METHOD SPECIFICATION. A REVIEW OF SPECIFICATIONS FOR ALL 50 STATES SHOWED THAT, IN GENERAL, THEY STIPULATE THE BITUMINOUS MIXTURE CONSISTENCY AND SPECIFY CERTAIN QUALITY REQUIREMENTS THAT MUST BE MET BY EACH INGREDIENT AND OCCASIONALLY BY THE MIX ITSELF. HOWEVER, THEY DO NOT CLEARLY DESIGNATE THAT THESE REQUIREMENTS SHALL APPLY AT THE DESIGN STAGE OR IN THE CONTROL STAGE. EMPHASIS IS PLACED ON THE AGGREGATE REQUIREMENTS. VERY FEW STATES SPECIFY QUALITY CONTROL OF THE MIXTURE. A SUMMARY OF SPECIFICATIONS OF ALL STATES IS PRESENTED IN A TABLE. ONE-QUARTER OF THE STATES USE END RESULT (USING RELATIVE DENSITY ONLY) SPECIFICATIONS. THE REMAINING STATES USE SOME TYPE OF METHOD OF PROCEDURAL SPECIFICATION WITH A GREAT DEAL OF VARIATION AS TO SPECIFIC REQUIREMENTS FOR TEMPERATURE, TYPES AND WEIGHTS OF COMPACTORS, NUMBER OF PASSES, ETC. PRIMARY FACTORS INFLUENCING THE COMPACTION OF ASPHALT PAVING MIXTURES ARE: (1) TEMPERATURE OF THE MIXTURE AT THE VARIOUS PHASES OF COMPACTION, (2) AIR TEMPERATURE AS IT AFFECTS MIX TEMPERATURE, (3) GRADATION AND SHAPE CHARACTERISTICS OF AGGREGATES, (4) ASPHALT CONTENT OF THE MIXTURE, (5) DEPTH OF MIX, AND (6) COMPACTIVE ENERGY (WEIGHT OF ROLLERS AND NUMBER OF COVERAGES). WATER PERMEABILITY TESTS ARE DISCUSSED USING A NEW TEST METHOD. THE NUCLEAR GAUGES FOR COMPACTION CONTROL IS DESCRIBED. THE EXPERIMENTAL WORK USING NUCLEAR GAUGES FOR OBTAINING RELATIVE DENSITY INDICATES THAT THIS EQUIPMENT HAS A GREAT DEAL OF POTENTIAL TO BE A MEANS FOR DEVELOPING A PRACTICAL END RESULT TYPE SPECIFICATION.

  • Supplemental Notes:
    • pp 1-22, 7 FIG, 2 TAB
  • Corporate Authors:

    National Asphalt Pavement Association

    5100 Forbes Boulevard
    Lanham, MD  USA  20706-4407
  • Authors:
    • Gillis, L R
  • Publication Date: 1968-2

Subject/Index Terms

Filing Info

  • Accession Number: 00214828
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jun 18 1994 12:00AM