GAP-GRADED VERSUS CONTINUOUSLY GRADED SHRINKAGE COMPENSATING CONCRETE

A COMPARATIVE STUDY IS PRESENTED OF EXPANSION-SHRINKAGE CHARACTERISTICS OF GAP-GRADED AND CONTINUOUSLY-GRADED SHRINKAGE-COMPENSATING TYPE-K CONCRETES. TYPE-K SHRINKAGE-COMPENSATING CEMENT CONTENT HAS BEEN ADOPTED AS THE MAIN VARIABLE PARAMETER. THE INFLUENCE OF THIS PARAMETER ON THE EXPANSION-SHRINKAGE CHARACTERISTICS IS STUDIED FOR 50 SPECIMENS OF GAP-GRADED AND CONTINUOUSLY-GRADED CONCRETES. SPECIMENS CONSISTED OF TWO TYPES: (1) WITH LATERAL REINFORCEMENT (1.16 PERCENT), AND (2) WITHOUT ANY REINFORCEMENT. THE SPECIMENS USED WERE 3 X 3 X 11.5-IN. CONCRETE PRISMS ON WHICH EXPANSION AND SHRINKAGE MEASUREMENTS WERE TAKEN ALONG THEIR LENGTHS. ALL THE SPECIMENS WERE MADE OUT OF TWO CONCRETE MIXES OF A 3/4-IN. MAXIMUM-SIZE AGGREGATE AND OF MEAN TARGET STRENGTH ABOUT 5500 PSI, ONE FOR GAP-GRADED AND THE OTHER FOR CONTINUOUSLY-GRADED CONCRETE, HAVING DIFFERENT PERCENTAGES OF TYPE-K CEMENT CONTENT. WITHIN THE RANGE AND PREMISES OF THE PRESENT INVESTIGATION, IT CAN BE CONCLUDED THAT UNRESTRAINED CONTINUOUSLY-GRADED SHRINKAGE-COMPENSATING CONCRETE REQUIRES 37.7 PERCENT MORE TYPE-K CEMENT, WHILE, WITH LATERAL RESTRAINT, IT REQUIRES 39.2 PERCENT MORE TYPE-K CEMENT, THAN THE EQUIVALENT GAP-GRADED SHRINKAGE-COMPENSATING CONCRETE HAVING SAME COMPRESSIVE STRENGTH AND WORKABILITY. THUS, THIS INVESTIGATION HAS SHOWN THAT A SIGNIFICANT ECONOMY CAN BE ACHIEVED FOR SHRINKAGE-COMPENSATING CONCRETES BY ADOPTING GAP GRADING INSTEAD OF THE CONVENTIONAL CONTINUOUS GRADING OF AGGREGATES. /AUTHOR/

  • Supplemental Notes:
    • Tech Rept NO 6, 642 (68)
  • Corporate Authors:

    South Dakota School of Mines and Technology, Rapid City

    501 East St Joseph Street
    Rapid City, SD  USA  57701

    South Dakota Department of Transportation

    700 East Broadway Avenue
    Pierre, SD  USA  57501

    Bureau of Public Roads /US

    400 7th Street, SW
    Washington, DC  USA  20590
  • Authors:
    • Li, S T
    • Ramakrishnan, V
    • Aranke, V R
  • Publication Date: 1970-5

Subject/Index Terms

Filing Info

  • Accession Number: 00212081
  • Record Type: Publication
  • Source Agency: Bureau of Public Roads /US
  • Files: TRIS, STATEDOT
  • Created Date: Jul 27 1970 12:00AM