USE OF WATER AND SET-REDUCING ADMIXTURE IN FLYASH CONCRETE

A METHOD FOR PROPORTIONING FLY ASH CONCRETE HAVING 28 DAYS STRENGTH EQUAL TO THAT OF STRAIGHT PORTLAND CEMENT CONCRETE IS PRESENTED. HOWEVER, THE MIX BEING STIFFER IN CONSISTENCY REQUIRES VIBRATION FOR COMPACTION. ADDITION OF WATER REDUCING SET RETARDING ADMIXTURES TO BOTH RICH AND LEAN FLY ASH CONCRETE HAS BEEN SHOWN TO LOWER W/C RATIO FOR ATTAINING WORKABILITY EQUAL TO THAT OF STRAIGHT PORTLAND CEMENT CONCRETE SO THAT THE CONCRETE PERMITS HAND COMPACTION. THE STRENGTH HAS BEEN SHOWN TO BE ALMOST EQUAL TO THAT OF CONTROL CONCRETE EVEN AT 7 DAYS AND 14 DAYS SO THAT USE OF DIFFERENT FLY ASH CONCRETE MIXES WILL NOT DELAY THE STRIKING OF THE FORM WORK. THE USE OF ADMIXTURES HAS BEEN SHOWN TO REDUCE BLEEDING AND AIR ENTRAINMENT IN FLY ASH CONCRETE AND PROLONG THE INITIAL SETTING TIME AND HENCE PERMIT VIBRATION OF CONCRETE TRANSPORTED FROM A LONG DISTANCE. /RRL/LCPC/A/

• Supplemental Notes:
  • Topic Iii-iV, REPT III-IV/14, PP 221-239, 3 FIG, 7 TAB,
• Authors:
  • CHOPRA, S K
  • Rehsi, S S
  • Garg, S K
• Conference:
  • Intl Symp Admix Mortar & Concr /Belg/
• Publication Date: 1967

Subject/Index Terms

• TRT Terms: Admixtures; Air entrainment; Bleeding; Compaction; Concrete; Concrete curing; Fly ash; Reduction (Chemistry); Setting (Concrete); Strength of materials; Vibration; Water; Water cement ratio; Workability
• Uncontrolled Terms: Setting time
• Old TRIS Terms: Reduction
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 00212776
• Record Type: Publication
• Source Agency: Road Research Laboratory /UK
• Files: TRIS
• Created Date: Jul 27 1970 12:00AM