UTILIZATION OF LOCALLY AVAILABLE VERY FINE SANDS IN THE DESIGN OF ECONOMICAL CEMENT CONCRETE MIXES

THE POSSIBILITY IS EXAMINED OF MAXIMUM UTILIZATION OF LOCALLY AVAILABLE VERY FINE SANDS IN DESIGNING ECONOMICAL CEMENT CONCRETE MIXES, USING BOTH CONTINUOUS AND GAP GRADATION OF THE COARSE AGGREGATES. THE POPULAR BELIEF THAT FINE AGGREGATES COMPRISING COARSE SAND ALONE WOULD NORMALLY GIVE HIGHER STRENGTH AND MORE ECONOMY IN A CEMENT CONCRETE MIX (PROVIDING OTHER CONDITIONS REMAIN THE SAME, AND THE COSTS OF VERY FINE SAND AND COARSE SAND ARE EQUAL) HAS BEEN FOUND TO BE INCORRECT. FOR THE PURPOSE OF THIS STUDY TWO LOCALLY AVAILABLE SANDS, BADARPUR AND JUMMA SANDS OF DELHI, OF WIDELY VARYING FINENESS MODULI (2.79 AND 1.0 RESPECTIVELY) WERE USED. THE INVESTIGATION SHOWS THAT EVEN WHEN THE COSTS OF BOTH VARIETIES OF SAND ARE THE SAME, IT IS MOR5 ECONOMICAL TO BLEND THE TWO SANDS IN EQUAL PROPORTIONS THAN TO USE THE COARSE VARIETY ALONE. THE STUDY FURTHER INDICATES THAT UP TO A BLENDING PROPORTION OF 60:40 OF VERY FINE SAND:COARSE SAND, THE MIX DESIGNED USING GAP-GRADING IN FINER FRACTIONS OF THE COARSE AGGREGATE GRADATION YIELDS MORE ECONOMICAL MIXES THAN WHEN CONTINUOUS GRADING IS ADOPTED. WITH GREATER PROPORTIONS OF VERY FINE SAND, HOWEVER, GAP GRADING IS LIKELY TO MAKE THE MIX UNECONOMICAL. THE EFFECTIVE ECONOMY OF VARIOUS MIXES HAS ALSO BEEN WORKED OUT WITH PARTICULAR REFERENCE TO PAVING CONCRETE. /RRL/A/

• Record URL:
  http://arrbknowledge.com
• Supplemental Notes:
  • Vol 3, Part 2, PAPER NO 231, PP 747-764, 6 FIG, 6 TAB, 6
• Corporate Authors:

  ARRB

  Melbourne, Victoria  Australia 
• Authors:
  • Ghosh, R K
  • Chatterjee, M R
• Conference:
  • Australian Road Research Board Conference Proc
• Publication Date: 1966

Subject/Index Terms

• TRT Terms: Admixtures; Aggregate gradation; Blending; Cement; Coarse aggregates; Fine aggregates; Fineness; Gap grading; Modulus; Sand
• Old TRIS Terms: Fineness modulus
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 00212934
• Record Type: Publication
• Source Agency: Road Research Laboratory /UK
• Files: TRIS, ATRI
• Created Date: Jun 15 1970 12:00AM