AN EVALUATION OF GAP-GRADED CONCRETES

In many parts of Louisiana the sources of naturally occurring continuously-graded aggregates are being depleted without any expectation of replacement. Many of the available marginal aggregate sources are rejected because of gap-grading, i.e., certain particle sizes are lacking, or the sizes and quantities of the coarse aggregate do not meet the existing specification requirements. This report describes a study which was undertaken to compare the behavior of gap-graded concretes with the behavior of continuously-graded concretes to determine whether or not the gap-graded concrete mixtures were comparable to the continuously-graded concrete mixtures. The five factors investigated in this study were coarse aggregate gradation, water-cement ratio, cement content, fine aggregate content, and length of curing. The fundamental material properties evaluated were compressive strength, modulus of elasticity, tensile strength, Poisson's ratio, and tensile strain, while the properties of the plastic concrete mix which were investigated included slump, density, air content, and workability.

• Supplemental Notes:
  • Sponsored in part by Louisiana Dept. of Transportation and Development, Baton Rouge, Office of Highways.
• Corporate Authors:

  Louisiana Tech University, Baton Rouge

  Materials Research Laboratory
  Baton Rouge, LA  United States  70801

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590

  Louisiana Department of Transportation and Development

  1201 Capitol Access Road, P.O. Box 94245
  Baton Rouge, LA  United States  70804-9245
• Authors:
  • Hadley, W O
• Publication Date: 1977-2

Media Info

• Pagination: 133 p.

Subject/Index Terms

• TRT Terms: Aggregates; Air content; Coarse aggregates; Compressive strength; Concrete; Concrete curing; Density; Gap grading; Grain size (Geology); Gravel; Mechanical properties; Modulus of elasticity; Poisson ratio; Polymer concrete; Slump test; Specifications; Tensile strength; Variables; Water cement ratio; Workability
• Uncontrolled Terms: Slumps
• Geographic Terms: Louisiana
• Old TRIS Terms: Continuous grading; Poissons ratio; Variations
• Subject Areas: Geotechnology; Highways; Materials;

Filing Info

• Accession Number: 00167027
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: FHWA-LA-77-73-1 Final Rpt., RR-73-1
• Files: NTIS, TRIS, USDOT, STATEDOT
• Created Date: Oct 29 1978 12:00AM