STATISTICAL EVALUATION OF EQUIPMENT AND OPERATOR EFFECTS ON THE RESULTS OF ASPHALT EXTRACTION TESTS

THE RELATIVE MAGNITUDE WAS STUDIED OF CERTAIN VARIATIONS ASSOCIATED WITH EXTRACTION TESTING AS CURRENTLY PERFORMED IN WEST VIRGINIA, SPECIFICALLY THOSE VARIATIONS ATTRIBUTABLE TO OPERATORS AND EQUIPMENT. IN ORDER TO STUDY THE DESIRED VARIATIONS AND EFFECTS, IT WAS NECESSARY TO MINIMIZE THE MAJOR COMPONENT MATERIALS VARIATIONS BY SUBSTITUTING OTTAWA SAND AND PORTLAND CEMENT FOR THE AGGREGATE AND FILLER PORTIONS RESPECTIVELY. A LARGE NUMBER OF IDENTICAL SAMPLES WERE SYNTHESIZED BY ACCUMULATIVELY WEIGHING EACH COMPONENT MATERIAL DIRECTLY INTO TARED CONTAINERS ON A CALIBRATED BALANCE. TEST RESULTS SHOW THAT SIGNIFICANT DIFFERENCES DO EXIST BETWEEN OPERATORS IN A GIVEN LABORATORY, BETWEEN METHODS WITHIN A GIVEN LABORATORY FOR A GIVEN OPERATOR, AND BETWEEN RESULTS OBTAINED AT DIFFERENT LABORATORIES USING THE EXISTING PRACTICE. THE REFLUX METHOD WAS FOUND TO BE SUBSTANTIALLY LESS SUSCEPTIBLE TO VARIATIONS IN OPERATOR TECHNIQUE. THIS WAS REFLECTED PRIMARILY IN THE ASH CORRECTION ANALYSES RESULTS. THE REFLUX DEVICE GENERALLY REQUIRES LESS EXACTING TECHNIQUES ON THE PART OF THE OPERATOR THAN DOES THE ROTAREX TO OBTAIN COMPARABLE RESULTS AND IT IS LESS SUSCEPTIBLE TO THE INTRODUCTION OF ERROR DUE TO ASH CORRECTION. THE ACTUAL AMOUNT (PERCENTAGE LEVEL) OF ASPHALT CEMENT IN THE SAMPLE APPEARS TO AFFECT THE PROFICIENCY OF GOOD OPERATORS, HOWEVER, THIS EFFECT APPEARS TO BE MINOR, SINCE THE INFLUENCE IS NOT DETECTABLE WHERE POORER OPERATORS ARE INVOLVED. THE VARIATION IN THE ASH CORRECTION FACTOR FOR THE REFLUX METHOD WAS FOUND TO HAVE A SMALL EFFECT ON THE PRECISION OF THE ASPHALT CEMENT CONTENT DETERMINATIONS. IT WAS FOUND FEASIBLE TO DEVELOP AN ADEQUACY CRITERIA BASED ON A STANDARD SAMPLE TEST TERIES, FOR THE PURPOSE OF EVALUATING THE ABILITY OF OPERATORS TO PERFORM FIELD EXTRACTION TESTS WITH ACCEPTABLE PROFICIENCY.

• Supplemental Notes:
  • Vol 36, Pp219-266, 15 FIG, 19 TAB, 5 REF
• Authors:
  • Steele, G W
  • Krieger, F L
• Conference:
  • Assoc Asphalt Paving Technol Proc
• Publication Date: 1967-2

Subject/Index Terms

• TRT Terms: Asphalt; Asphalt cement; Asphalt tests; Chemical analysis; Fluxes; Personnel performance; Resource extraction; Statistical analysis
• Uncontrolled Terms: Extraction (Chemistry)
• Old TRIS Terms: Operator performance; Refluxing
• Subject Areas: Data and Information Technology; Highways; Materials;

Filing Info

• Accession Number: 00210716
• Record Type: Publication
• Files: TRIS
• Created Date: May 1 1994 12:00AM