GAP-GRADED AGGREGATES FOR HIGH-STRENGTH QUALITY CONCRETE

To determine the optimum proportion of materials used in a mix design to achieve a specified quality with least cost is the most important aspect in the production of concrete. Currently available methods for proportioning aggregates are based mosthly on previous experience. Even their application to the conventional continuously graded concrete is short of being optimum. It has become essential to seek quantitative information for the optimum proportioning of gap-graded and continuously graded aggregates for various significant mix parameters. In the present work involving 200 mixes with tests carried out according to ASTM standard methods, the results have been analyzed with the objective of revealing optimum mix proportions with respect to significant mix parameters, such as size and quantity of coarse aggregate, size and quantity of the fine aggregate, cement content, and water-cement ratio, at pratically the same air content for both gap-graded and continuously graded concretes. The optimum cement contents for both concretes are on the basis of equal mazimum size of coarse aggregate and equal compressive strength. The comparison has shown that much less cement is required for concrete with gap-graded aggregates than its continuously graded counterpart with approximately the same workability. Gap grading of the aggregates results in lower requirement of water content, and hence lower water-cement ratio, and permits a higher aggregate-cement ratio to achieve the same workability as its continuously graded counterpart with equal cement content and equal maximum size of coarse aggregate.

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 17-32
  • Monograph Title: Grading of concrete aggregates
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00159544
  • Record Type: Publication
  • ISBN: 0309021723
  • Files: TRIS, TRB
  • Created Date: Sep 20 1977 12:00AM