THE EVALUATION OF ALTERNATE CAPPING PROCEDURES FOR CONCRETE 28 DAY QUALITY ASSURANCE SPECIMENS

This study is based on a designed experiment to determine the feasibility of using pressure pads in the testing of 28 day concrete test cylinders. The scope of the investigation includes four types of pressure pads (Celotex, Upson Board, Rubber Belt and Steel End Caps with Rubber inserts) as well as the Sulphur Mortar Caps which are intended as the reference standard. The design required 15 batches of concrete to fabricate ten 6 inch x 12 inch concrete cylinder specimens. All batches were made with one aggregate of one gradation, one brand of cement, and cement constants of 5.0, 6.0 and 7.25 bags/cubic yard. Test results indicate that the average concrete compressive strengths are less when tested using either Celotex, Upson Board or Rubber Belt pressure pads than when the specimens are tested with Sulphur Mortar caps. However, the Sulphur Mortar and the Steel End Caps with inserts have about the same strengths. The within-test variations are good to excellent for the Steel End Caps but the other non-standard caps generally show a poor within-test variation. The unit material cost per test for the Steel End Caps with rubber inserts is about the same as the standard and considerably less when equipment purchase price, installation costs, personnel safety and time, and energy costs are considered. The Steel End Caps with rubber inserts are an acceptable alternate for the standard method of capping 28 day concrete test specimens.

  • Supplemental Notes:
    • Prepared for West Virginia Dept. of Highways, Charleston.
  • Corporate Authors:

    Woodward-Clyde Consultants

    Materials Research and Development Division
    Rockville, MD  USA 

    West Virginia Department of Highways

    1900 Kanawha Boulevard East
    Charleston, WV  USA  25305

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  USA  20590
  • Authors:
    • Bowery, F J
    • Higgins, F T
  • Publication Date: 1978-1

Media Info

  • Pagination: 60 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00180807
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: FHWA-WV-77-13 Final Rpt., WCC-MRD-77-765
  • Contract Numbers: 52
  • Files: NTIS, TRIS, USDOT, STATEDOT
  • Created Date: Sep 14 1978 12:00AM