DISCUSSION OF HOW AGGREGATE PARTICLE SHAPE INFLUENCES CONCRETE MIXING WATER REQUIREMENT AND STRENGTH

A PAPER IS DISCUSSED THAT ADVANCES THE THEORY THAT AGGREGATE SHAPE CHARACTERISTICS HAVE A PROFOUND EFFECT ON MIXING WATER REQUIREMENTS AND STRENGTH CHARACTERISTICS OF PORTLAND CEMENT CONCRETE. INVESTIGATIONS BY THE NATIONAL CRUSHED STONE ASSOCIATION (NCSA) HAVE GIVEN GENERAL RESULTS PARALLEL WITH THOSE REPORTED BY THE AUTHOR. SPECIFIC DATA ARE DISCUSSED FROM THESE STUDIES. IT IS POINTED OUT THAT THE NCSA RESULTS CLEARLY ISOLATE THE PARTICLE SHAPE CHARACTERISTIC AS EACH OF THE SANDS WERE PREPARED FROM THE SAME PARENT ROCK AND THE VARYING SHAPES ARTIFICALLY ACHIEVED THROUGH LABORATORY PROCESSING. THE ACTUAL PROCEDURE USED FOR DETERMINING PARTICLE SHAPE DIFFERS SOMEWHAT FROM THAT DESCRIBED BY THE AUTHOR, GIVING SOMEWHAT HIGHER VOID PERCENTAGES. THE AUTHOR AGREES WITH THE OBSERVATION THAT DIFFERENT VOID CONTENTS ARE ATTRIBUTABLE TO DIFFERENCES BETWEEN THE TWO MEASUREMENT PROCESSES. HE CONCLUDES THAT THE CONCEPT THAT AGGREGATE SHAPE FEATURES INFLUENCE THE PROPERTIES OF MORTAR AND CONCRETE IS APPLICABLE TO MOST NORMAL WEIGHT AGGREGATES WHETHER NATURAL OR MANUFACTURED IN ORIGIN. FURTHER WORK IS UNDER WAY IN THE LABORATORY OF THE NATIONAL SAND AND GRAVEL ASSOCIATION TO REFINE MEASUREMENT OF BULK VOID CONTENT AND TO DETERMINE IF A TENTATIVE TEST METHOD IS AVAILABLE. REFERENCES: HOW AGGREGATE PARTICLE SHAPE INFLUENCES CONCRETE MIXING WATER REQUIREMENT AND STRENGTH, M. H. WILLS, JR., JOURNAL OF MATERIALS, VOL. 2, NO. 4, PP. 843-865, DEC. 1967.

• Supplemental Notes:
  • Vol 3, No 3, PP 556-558, 1 FIG
• Corporate Authors:

  American Society for Testing and Materials (ASTM)

  100 Barr Harbor Drive, P.O. Box C700
  West Conshohocken, PA  United States  19428-2957
• Authors:
  • Renninger, F A
• Publication Date: 1968-9

Media Info

• Serial:
  • Journal of Materials
  • Publisher: American Society for Testing and Materials (ASTM)

Subject/Index Terms

• TRT Terms: Aggregates by shape and surface texture; Compressive strength; Mixing; Particles; Portland cement concrete; Shape; Test procedures; Void ratios; Water consumption
• Uncontrolled Terms: Aggregate shape
• Old TRIS Terms: Determination; Particle shapes; Water requirements
• Subject Areas: Geotechnology; Highways;

Filing Info

• Accession Number: 00217772
• Record Type: Publication
• Files: TRIS
• Created Date: Aug 11 1970 12:00AM