PRECISION OF QUARTZ CRYSTAL AND MERCURY DIFFERENTIAL THERMOMETERS IN HEAT-OF-HYDRATION TEST

THE PRECISION OF A QUARTZ CRYSTAL THERMOMETER WAS DIRECTLY COMPARED WITH THAT OF A MERCURY DIFFERENTIAL THERMOMETER IN THE DETERMINATION OF THE HEAT OF SOLUTION OF A TYPE II LOW-HEAT PORTLAND CEMENT AND A HARDENED PASTE MADE WITH THE CEMENT. TEST PROCEDURES PRESCRIBED IN METHOD 3101.1 OF FEDERAL TEST METHOD STANDARD NO. 158A WERE FOLLOWED. THE CALORIMETER TEMPERATURE RISE WAS DETERMINED DURING SOLUTION OF ZINC OXIDE, DRY CEMENT, AND 7-DAY HYDRATED PASTE. THE HEAT-OF-HYDRATION TEST RESULTS, WHETHER OBTAINED WITH THE QUARTZ CRYSTAL THERMOMETER OR THE DIFFERENTIAL THERMOMETER, CALCULATED USING THE ALTERNATE OR THE REGULAR METHOD OF THE FEDERAL STANDARD, WERE ESSENTIALLY THE SAME. THE TEST PRECISION OBTAINED USING THE QUARTZ CRYSTAL THERMOMETER WAS FAR POORER THAN EXPECTED, DUE TO ITS LOW THERMAL MASS IN CONTRAST TO THE HIGH THERMAL MASS OF THE REST OF THE CALORIMETER SYSTEM. THE TEST RESULTS INDICATED THAT CALIBRATED DIFFERENTIAL THERMOMETERS ARE NOT NEEDED FOR THIS TEST PROCEDURE. THE TEST RESULTS ALSO INDICATED THAT PROPERLY PREPARED ZINC OXIDE DOES NOT DISSOLVE AT THE SAME RATE AS DRY CEMENT, BUT DISSOLVES AT A RATE TWO TO THREE TIMES AS FAST AS THE DRY CEMENT. /AUTHOR/

  • Supplemental Notes:
    • No C-69-11, 22 PP
  • Authors:
    • Pepper, L
  • Publication Date: 1969-7

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  • Accession Number: 00213426
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jan 19 1970 12:00AM