INVESTIGATION OF THE IMPACT-TYPE CONCRETE TEST HAMMER

THIS WORK DESCRIBES A SERIES OF TESTS DESIGNED TO DETERMINE THE RELIABILITY OF RESULTS, THE FEASIBILITY OF USE, AND THE PRACTICAL APPLICATIONS OF THE TEST HAMMER IN CONSTRUCTION CONTROL. TEST RESULTS ARE COMPARED TO THE PUBLISHED FINDINGS OF OTHER INVESTIGATORS AND THE RELIABILITY OF CALIBRATION CURVES UNDER VARIOUS TEST CONDITIONS IS CAREFULLY INVESTIGATED. INDICATED STRENGTHS ARE SIGNIFICANTLY AFFECTED BY SPECIMEN SIZE, RESTRAINT OR CLAMPING IN TESTING MACHINE, SURFACE TEXTURE, MIX PROPORTIONS, AND TYPE OF AGGREGATE. COEFFICIENT OF VARIATION OVER A WIDE VARIETY OF SPECIMENS AVERAGE 18.8 PERCENT AND EXCEEDED 30 PERCENT FOR SOME GROUPS OF SPECIMENS. IT IS RECOMMENDED THAT SPECIAL CALIBRATIONS BE PROVIDED FOR EACH MIX OR CHANGE OF AGGREGATE, AND THAT USE OF THE TEST HAMMER ON WEAK OR YOUNG CONCRETE BE KEPT TO A MINIMUM BECAUSE SUCH TESTING MAY PRODUCE SIGNIFICANT SURFACE BLEMISHES. /AUTHOR/

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  • Supplemental Notes:
    • No 305, pp 14-27, 11 FIG, 5 TAB, 4 REF Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
  • Authors:
    • Mitchell, L J
    • Hoagland, G G
  • Conference:
  • Publication Date: 1961

Media Info

  • Media Type: Digital/other
  • Monograph Title: Tests for concrete and durability of concrete aggregates
  • Serial:

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Filing Info

  • Accession Number: 00213194
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Sep 12 1994 12:00AM