THE EFFECT OF THE CLASSIFICATION OF SAND ON THE STRENGTH OF CONCRETE

AS THE TECHNOLOGY OF CONCRETE DEVELOPED, GREAT IMPORTANCE BEGAN TO BE ATTRIBUTED TO THE ROLE PLAYED BY THE SURFACE OF FINE AND FINEST GRAINS IN A CONCRETE MASS. METHODS WERE SOUGHT WHICH WOULD ELIMINATE UNNECESSARY FRACTIONS FROM SAND. USING A WATER CLASSIFIER WAS ONE OF THE METHODS. NOT ONLY WAS SAND EASILY SEPARTED IN THIS APPARATUS INTO TWO OR MORE FRACTIONS, BUT IT WAS COMPLETELY FREED OF IMPURITIES AND THE FINEST FRACTIONS. A DESCRIPTION IS GIVEN OF THE OPERATION OF THE CLASSIFIER AND OF THE WAY AN EXAMINATION IS MADE. THREE FRACTIONS OBTAINED FROM THE CLASSIFIER WERE USED' ELUTRIATED GRAVEL /3-20 MM/, ELUTRIATED FINE SAND /0.8-3 MM/ AND ELUTRIATED FINE SAND /0.1-0.8/. GRADES OF CEMENT 350 AND 400 WERE USED FOR THE EXAMINATION. THE WATER- CEMENT RATIO VARIED FROM 0.57 TO 0.32. IT WAS FOUND THAT LARGE DIFFERENCES IN STRENGTH WERE OBTAINED BY USING THE PROPER SAND POINT WHEN A CHANGE WAS MADE IN THE PROPORTIONS OF FINE TO COARSE SAND. THE BEST RESULTS WERE OBTAINED AT A 33 PERCENT SAND POINT WHEN THERE WAS AN AMOUNT OF 60 PERCENT OF FINES IN THE TOTAL AMOUNT OF SAND. THE FOLLOWING COMPRESSION STRENGTH WAS OBTAINED AFTER 28 DAYS FOR GRADE OF CEMENT 400, DOSED IN AMOUNTS OF 500 KG PER CU M' GRAVEL AND UNWASHED SAND-271 KG PER SQ CM, GRAVEL AND ELUTRIATED SAND- 612 KG PER SQ CM. /CR/

  • Supplemental Notes:
    • No 7-8, pp 198-206
  • Corporate Authors:

    Cement, Wapno, Gips /Poland

    ,    
  • Authors:
    • Zelenski, K
  • Publication Date: 1964

Subject/Index Terms

Filing Info

  • Accession Number: 00212414
  • Record Type: Publication
  • Source Agency: Am Concrete Inst Journal & Proceedings
  • Files: TRIS
  • Created Date: Aug 30 1994 12:00AM