CONCRETE CORE STRENGTH--THE EFFECT OF LENGTH TO DIAMETER RATIO

The ASTM Method for Obtaining and Testing Drilled Cores and Sawed Bams of Concrete (C 42-68) currently contains length to diameter ratio correction factors for soaked cores but not dried cores. However, it is widely recognized that for structures which will be substantially dry in service dried cores are more appropriate. It is sometimes difficult--because of constraints of aggretate size, reinforcing bar placement, and member dimensions--to obtian drilled cores of the preferred dimensions, with a length twice the diameter. Research performed in two laboratories involving the drilling and testing of a large number of 4-in. (102-mm) diameter soaked and dried cores with length to diameter ratios, of 1.0, 1.25, 1.5, 1.75, and 2.0, taken from six structural-size members, indicates that the same correction factors can be used for both moisture conditions and that the factors now in ASTM Method C 42-68 should be lowered slightly. In addition, data were gathered on the effect of end preparation procedure on core strength. For the methods used (three capping procedures and grinding of the ends) no important differences in measured strength were noted. /Author/

  • Corporate Authors:

    American Society for Testing and Materials

    100 Barr Harbor Drive, P.O. Box C700
    West Conshohocken, PA  USA  19428-2957
  • Authors:
    • MEININGER, R C
    • Wagner, F T
    • Hall, K W
  • Publication Date: 1977-5

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Filing Info

  • Accession Number: 00165800
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Dec 27 1977 12:00AM