An investigation has been made, at five construction sites, of the strength of in situ concrete and its variation within and between structural elements. Comparisons have been made between the in situ strength and the strength of control specimens to provide further data on the magnitude of gamma sub m, the partical safety factor for strength of materials. The method of determining the in situ strength was the non- destructive technique of measuring the ultrasonic pulse velocity. Although the mean in situ strengths of most of the columns and walls tested at 28 days were found to range between 60 and 70% of the corresponding mean control cube strengths, the strengths had increased by about 25% by 6 months after casting. At present the value of 1.5 for gamma sub m seems satisfactory in practice. /Author/

  • Corporate Authors:

    Cement and Concrete Association

    Wexham Spring
    Slough SL3 6PL, Buckinghamshire,   England 
  • Authors:
    • Davis, S G
  • Publication Date: 1976-4

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: 19 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00141352
  • Record Type: Publication
  • Report/Paper Numbers: 42.514 Tech. Rpt.
  • Files: TRIS
  • Created Date: Jan 16 1977 12:00AM