VOID SPACING AS A BASIS FOR PRODUCING AIR-ENTRAINED CONCRETE

BASIC STUDIES SHOW THAT THE FUNCTION OF ENTRAINED AIR IS TO PROTECT THE PASTE AND THAT THE EFFECTIVENESS DEPENDS ON THE DISTANCE FROM VOID TO VOID IN THE PASTE. FREEZING AND THAWING TESTS SHOW DIFFERENT MIXES HAVE NEARLY EQUAL FROST RESISTANCE WHEN THE SPACING FACTOR IS ABOUT 0.01 INCH. THE AMOUNT OF AIR REQUIRED FOR A GIVEN SPACING FACTOR IS DIRECTLY PROPORTIONAL TO THE PASTE CONTENT AND IS GREATER THE SMALLER THE SPECIFIC SURFACE OF THE AIR VOIDS. WITH A GIVEN AMOUNT OF AIR-ENTRAINING AGENT IN THE MIXING WATER, THE AMOUNT OF ENTRAINED BUBBLES IS SMALLER THE GREATER THE QUANTITY OF CEMENT OR OTHER FINE SOLIDS IN THE WATER. A PROCEDURE IS SUGGESTED FOR DESIGNING A FIXED SPACING FACTOR WHERE SUCH PROCEDURE IS ECONOMICALLY FEASIBLE. /PCA/

• Authors:
  • Powers, T C
• Publication Date: 0

Media Info

• Serial:
  • Portland Cement Assoc R & D Lab Bull
  • Issue Number: 0

Subject/Index Terms

• TRT Terms: Air entrained concrete; Air entraining agents; Freeze thaw tests; Pastes; Spacing; Specific surface; Void ratios
• Old TRIS Terms: Air void ratio; Void
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 00213498
• Record Type: Publication
• Source Agency: Portland Cement Association
• Report/Paper Numbers: No 49
• Files: TRIS
• Created Date: May 25 1970 12:00AM