ORGANIC IMPURITIES IN SAND THAT INTERFERE WITH THE HYDRATION OF PORTLAND CEMENT: A TEST FOR DETECTING THEIR PRESENCE

AS A RESULT OF THE INVESTIGATION, IT WAS CONCLUDED THAT: (1) THE TEST PROVIDES A SIMPLE AND RAPID METHOD THAT WOULD DISTINGUISH BETWEEN CONTAMINATED AND UNCONTAMINATED SANDS. HOWEVER, THE DISTINCTION WAS NOT CLEARLY DEFINED AND WAS MASKED BY THE EXPERIMENTAL ERROR BETWEEN LABORATORIES. THEREFORE, ONLY SANDS GIVING PH VALUES ABOVE 12.4 OR BELOW 12.2 COULD BE PLACED IN DISTINCT CATEGORIES. CONSEQUENTLY SANDS WITH PH VALUES BETWEEN 12.2 AND 12.4 WERE PLACED IN A BORDER-LINE CATEGORY. (2) THE REPRODUCIBILITY OF THE PH RESULTS WITHIN A LABORATORY WAS ONLY PLUS OR MINUS 0.05 PH UNITS AND BETWEEN LABORATORIES IT WAS PLUS OR MINUS 0.1 PH UNITS. (3) SANDS IN THE BORDER-LINE CATEGORY COULD BE ASSESSED BY HEATING THEM AT 600 DEGREES C FOR ONE HOUR. IF THE RESULTING INCREASE IN PH WAS MORE THAN 0.2 PH UNITS THEY WERE CONTAMINATED. (4) THE SUSCEPTIBILITY OF PORTLAND CEMENT TO ORGANIC CONTAMINATION VARIED FROM BATCH TO BATCH. CEMENTS THAT WERE LESS SUSCEPTIBLE TO ORGANIC CONTAMINATION WERE NOT SUITABLE FOR THE TEST AND COULD BE ELIMINATED BY DETERMINATION OF THE PH THAT THEY GAVE WHEN MIXED WITH A STANDARD SAND CONTAMINATED WITH 0.4 PER CENT OF TANNIC ACID. /AUTHOR/

  • Supplemental Notes:
    • Vol 125, No 3814, PP 32-42
  • Authors:
    • SHERWOOD, P T
    • Roeder, A R
  • Publication Date: 1965-7-10

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  • Accession Number: 00212469
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jan 16 1994 12:00AM