EFFECT OF POROSITY ON THE STRENGTH OF CONCRETE

AN EXPONENTIAL FUNCTION IS RECOMMENDED FOR THE COMPRESSIVE STRENGTH VERSUS AIR CONTENT RELATIONSHIP. EXPERIMENTAL EVIDENCE SHOWS THAT A CHANGE IN THE AIR CONTENT AFFECTS THE COMPRESSIVE STRENGTH OF A CONCRETE MORE THAN ITS FLEXURAL OR TENSILE STRENGTHS. EXPERIMENTAL RESULTS ALSO INDICATE HIGHER SENSITIVITY OF THE COMPRESSIVE STRENGTH WHEN THE CHANGE IN POROSITY IS CAUSED BY A CHANGE IN THE WATER-CEMENT RATIO OR AGE. AN APPROXIMATE FORMULA IS PRESENTED WHICH PROVIDES THE EFFECT OF WATER-CEMENT RATIO ON THE RATIO OF FLEXURAL STRENGTH TO COMPRESSIVE STRENGTH OF COMPARABLE CONCRETES. APPROXIMATE FORMULAS ARE PRESENTED WHICH ARE OBTAINED FROM THE PROPOSITION THAT A CHANGE IN THE WATER-CEMENT RATIO AFFECTS THE CONCRETE STRENGTH THROUGH A CHANGE IN POROSITY OF THE HARDENED PASTE. ONE OF THESE FORMULAS PROVIDES A FAMILY OF CONVERGING STRAIGHT LINES IN THE STRENGTH VERSUS LOG (WATER-CEMENT RATIO) SYSTEM FOR COMPARABLE CONCRETES OF VARIOUS AGES AS WELL AS FOR COMPARABLE COMPRESSIVE, FLEXURAL, AND TENSILE STRENGTHS. POSSIBILITIES FOR THE REFINEMENT OF THIS FORMULA ARE DISCUSSED. /AUTHOR/

• Supplemental Notes:
  • Vol 4, No 2, PP 356-371
• Authors:
  • Popovics, S
• Publication Date: 1969-6

Media Info

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

Subject/Index Terms

• TRT Terms: Age; Air content; Compressive strength; Concrete; Flexural strength; Formulas; Porosity; Tensile strength; Water cement ratio
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 00213395
• Record Type: Publication
• Files: TRIS
• Created Date: Sep 29 1994 12:00AM