REDUCTION OF APPARENT AGGREGATE VARIATION THROUGH IMPROVED SAMPLING

AN IMPROVED METHOD OF SAMPLING AGGREGATES IN BULK IS ESTABLISHED. IT IS SIMPLE, ECONOMICALLY FEASIBLE, AND MORE CONSISTENT THAN THOSE USED IN THE PAST. THE MATERIALS ENGINEER IS GIVEN A RELIABLE MEASURE OF THE MATERIAL USED AND IS PERMITTED ACCURATE DESIGN OF MIXES. THE IMPROVED RELIABILITY OF THE SAMPLES WILL REDUCE THE FREQUENCY OF ERRONEOUS WORK STOPPAGES AND THUS BENEFIT THE SUPPLIER. THE METHOD IS STATISTICALLY ORIENTED, BASED ON THE PRINCIPLE THAT EXTREME VALUES ARE LESS PROBABLE IN LARGE SAMPLES. IN PRINCIPLE, A TRUCK LOAD OF MATERIAL IS THE SAMPLE. WHETHER DRAWN FRON BINS OR LOADED FROM STOCK PILES, IT WILL MORE NEARLY REPRESENT THE BULK OF THE MATERIAL. THE FREQUENCY OF SAMPLING CAN BE REDUCED, AS STATISTICALLY THE FREQUENCY IS INTERRELATED WITH STANDARD DEVIATION. A REDUCTION IN DEVIATION WILL PERMIT REDUCED SAMPLING. IT WAS NECESSARY TO DETERMINE THE NUMBER OF SAMPLES FROM A SINGLE TRUCK REQUIRED TO GIVE A HIGH STATISTICAL CONFIDENCE THAT THE MEAN OF THE SAMPLES TRULY REPRESENTS THE TRUCK LOAD. FINALLY, IN ORDER TO KEEP THE VOLUME OF TESTING WITHIN BOUNDS, THE SAMPLES FROM ONE TRUCK ARE COMBINED INTO ONE SAMPLE WHICH REDUCES THE TESTING BY MECHANICALLY AVERAGING THE INDIVIDUAL SAMPLES . /AUTHOR/

  • Record URL:
  • Supplemental Notes:
    • Report Jhr 66-1,84PP
  • Corporate Authors:

    University of Connecticut, Storrs

    School of Engineering
    Storrs, CT  USA  06268
  • Authors:
    • Stephens, J E
  • Publication Date: 1966-5

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Filing Info

  • Accession Number: 00217540
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 1 1994 12:00AM