FIELD EXPERIMENT WITH STATISTICAL METHODS - BITUMINOUS CONCRETE

A RANDOM SAMPLING PROGRAM WAS INITIATED ON 41 MAINTENANCE SCHEDULES DURING 1967 IN VIRGINIA. THE PROGRAM WAS UNDERTAKEN TO GAIN EXPERIENCE IN APPLYING STATISTICAL CONCEPTS IN THE FIELD AND SPECIFICALLY IN RANDOM SAMPLING. INFORMATION ON VARIABILITY HAD BEEN REQUESTED, INCLUDING FIELD TESTS FOR RECORDING DATA THAT WILL BE USED IN A SUBSEQUENT STUDY RELATED TO STORING AND ANALYZING TEST DATA WITH AN IBM CARD SYSTEM. A SHORT COURSE ON STATISTICAL QUALITY CONTROL WAS GIVEN TO ALL MATERIALS ENGINEERS. RANDOM SAMPLES WERE TAKEN IN THE STATISTICAL EXPERIMENT ON ALL MAINTENANCE RESURFACINGS. FOUR MEASUREMENTS WERE MADE ON ASPHALT CONTENT AND GRADATION PER 160 TRUCK LOADS. A SUMMATION IS PRESENTED OF THE STANDARD DEVIATIONS OF ASPHALT CONTENT. THE DATA SUGGEST THAT STANDARD DEVIATIONS OF .25% - .30% WILL BE ENCOUNTERED ON ROUTINE MAINTENANCE JOBS. THE DIFFERENCES BETWEEN THE JOB MIX AND THE EXTRACTION GRADATIONS ARE SHOWN IN TABLES. THE STANDARD GRADATION DEVIATIONS VARY FROM 3.0 - 3.5 PERCENT ON THE COARSE SIEVES TO 1 PERCENT ON THE NO 100 SIEVE. THE FIELD EXPERIMENT DEMONSTRATED THAT RANDOM SAMPLING COULD BE ACCOMPLISHED BY THE NORMAL INSPECTION PERSONNEL. DATA VERIFIED THE BELIEF THAT A TARGET MISS ALLOWANCE IS NECESSARY IF SPECIFICATIONS ARE TO BE FAIR. A TARGET MISS ALLOWANCE SHOULD BE RECOGNIZED AS AN OPERATIVE FACTOR FOR FUTURE STATISTICAL RESEARCH.

  • Supplemental Notes:
    • 16 Pp, 2 FiG, 12 TAB, 2 APP
  • Corporate Authors:

    Virginia Highway Research Council

    Charlottesville, VA  USA 
  • Authors:
    • Dillard, J H
  • Publication Date: 1968-9

Subject/Index Terms

Filing Info

  • Accession Number: 00211398
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jun 2 1994 12:00AM