THE EFFECT OF GRADING ON LEAN-MIX CONCRETE

Severe nontraffic-load-associated cracking of lean-mix concrete (cement-treated) bases in the highveld region of the Republic of South Africa led to a laboratory investigation into some engineering properties of this material. This paper covers the first part of the laboratory study in which the effect of grading on flexural strength, tensile strength, strain at brake, and drying shrinkage strain were investigated. Three aggregate gradings using the same aggregate with varying cement and water contents were tested at approximately 96 percent modified AASHO density in beam flexure, direct and indirect tension, and drying shrinkage. A mix having a relatively low water-cement ratio and the coarsest grading yielded the highest flexural strength, static elastic modulus, and tensile strength and lowest short-term drying shrinkage strain. These findings point to a possible revision of current specifications for lean-mix concrete bases that could lead to an improved performance of this base material in practice.

Media Info

  • Media Type: Print
  • Features: Figures; Photos; Tables;
  • Pagination: pp 86-96
  • Monograph Title: Grading of concrete aggregates
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00159550
  • Record Type: Publication
  • ISBN: 0309021723
  • Files: TRIS, TRB
  • Created Date: Sep 20 1977 12:00AM