RESEARCH TO DEVELOP PROCEDURES USING STATISTICAL METHODS FOR CONTROL AND ACCEPTANCE OF HOT MIX ASPHALTIC CONCRETE

THE OBJECTIVE OF THIS RESEARCH PROJECT WAS TO DEVELOP PROCEDURES BASED ON STATISTICAL METHODS FOR CONTROL AND ACCEPTANCE OF ASPHALTICE CONCRETE MIXTURES USED BY THE GEORGIA DEPARTMENT OF TRANSPORTATION. PRESENT PROCEDURES ARE BASED ON TEST RESULTS FROM EXTRACTION TESTS BY THE CENTRIFUGE METHOD AND DENSITY TESTS ON CORES DRILLED FROM PAVEMENT. STATISTICAL VALUES PARTICULARLY STANDARD DEVIATIONS WERE DETERMINED FOR THESE TESTS ON RANDOM SAMPLES OBTAINED FROM TRUCKS AT THE PLANT AND RANDOM SAMPLES FROM THE ROADWAY AFTER THE MIX WAS SPREAD FOR SEVERAL TYPES OF ASPHALTIC MIXTURES PRODUCED AND ACCEPTED UNDER EXISTING SPECIFICATIONS AND PRACTICES. BASED ON THE DATA FROM THIS EXPLORATORY SERIES, A TENTATIVE SYSTEM FOR CONTROL AND ACCEPTANCE WAS DEVISED. THIS SYSTEM CONTAINS DETAILED METHODS FOR OBTAINING RANDOM SAMPLES AND USES TEST RESULTS FROM FIVE RANDOM SAMPLES FROM EACH LOT OR UNIT (APPROXIMATELY A DAY'S PRODUCTION). INDIVIDUAL RESULTS AND GROUPED DATA (AVERAGE OF THE FIVE RESULTS) ARE PLOTTED ON CONTROL CHARTS PREPARED BY THE "STANDARD GIVEN" TECHNIQUE WITH VALUES OF THE JOB-MIX FORMULA AS THE CENTRAL VALUE FOR EACH PROPERTY. CRITERIA ARE GIVEN FOR ANALYZING THESE CHARTS FOR INDICATION OF CHANGES NEEDED TO AVOID PRODUCING A LOT OUT OF CONTROL AND, THEREFORE, UNACCEPTABLE. FOR LOTS FOUND TO BE UNACCEPTABLE A METHOD IS GIVEN FOR ADJUSTING THE BID PRICE ON A GRADUATED SCALE FROM A VERY LITTLE AMOUNT WHEN THE DEVIATION IS SMALL TO AN APPRECIABLE AMOUNT WHEN THE DEVIATION IS SO LARGE THAT IT MAY IMPAIR THE SERVICEABILITY OF THE MIX. THIS SYSTEM HAS BEEN TESTED ON NINE PROJECTS INCLUDING THE TYPES OF MIXES, DIFFERENT MATERIALS AND PLANTS USED IN THE DEPARTMENT'S WORK. IT APPEARS THAT THE SYSTEM IS WORKABLE AND PRACTICAL BUT FULL EVALUATION OF THE RESULTS HAS NOT BEEN COMPLETED. A SPECIAL INVESTIGATION OF THE EXTRACTION TEST WAS MADE BECAUSE OF VARIATIONS NOTED IN THE RESULTS FROM THIS PROCEDURE.

  • Supplemental Notes:
    • 6 APP
  • Corporate Authors:

    Georgia Department of Transportation

    One Georgia Center
    600 West Peachtree Street, NW
    Atlanta, GA  United States  30308
  • Publication Date: 1972-2

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 266 p.
  • Serial:
    • Issue Number: 6908

Subject/Index Terms

Filing Info

  • Accession Number: 00211854
  • Record Type: Publication
  • Report/Paper Numbers: Final Rpt
  • Files: TRIS, STATEDOT
  • Created Date: Apr 3 1974 12:00AM