THE PORE SIZE DISTRIBUTION OF PORTLAND CEMENT PASTE

AN INVESTIGATION WAS CONDUCTED TO DETERMINE AS COMPLETELY AS POSSIBLE THE PORE SIZE DISTRIBUTION OF PORTLAND CEMENT PASTE. IN ADDITION TO MEASURING PORE DIAMETERS OVER A WIDE RANGE, THE EFFECTS OF WATER/CEMENT RATIO AND DEGREE OF HYDRATION (AGE) WERE INVESTIGATED. A REVIEW WAS MADE OF PUBLISHED PORE SIZE DISTRIBUTION CURVES AND THEORIES OF PORE SIZE DISTRIBUTION FOR PORTLAND CEMENT PASTE CALLED ATTENTION TO THE METHOD OF MEASUREMENT AND THE RANGE OF PORE DIAMETERS MEASURED. MERCURY INTRUSION WAS USED TO MEASURE PORES WITH DIAMETERS BETWEEN 1000 MUN 0.0085 MUN AND CAPILLARY CONDENSATION (USING WATER VAPOR) WAS USED BETWEEN THE PORE DIAMETER LIMITS OF 0.1000 MUN AND 0.0030 MUN. EQUIPMENT AND EXPERIMENTAL DETAILS OF THE MERCURY INTRUSION TECHNIQUE DISCUSSED IN DETAIL INCLUDE NECESSARY MODIFICATIONS TO A COMMERCIALLY AVAILABLE POROSIMETER, THE DESIGN AND USE OF THE NEW MACROW-POROSIMETER AND SPECIFIC ASSESSMENT OF SUCH FACTORS IS THE DIFFERENCE BETWEEN THEORETICAL AND EFFECTIVE MERCURY COMPRESSIBILITY AND HEATING DUE TO COMPRESSION. THE METHODS OF MERCURY INTRUSION AND CAPILLARY CONDENSATION OF WATER VAPOR ARE BOTH APPLICABLE AND USEFUL TECHNIQUES FOR MEASURING THE PORE SIZE DISTRIBUTION OF PORTLAND CEMENT PASTE. THE RESULTS OF MERCURY INTRUSION TESTS INDICATE THAT, AN ANY STAGE IN HYDRATION, THERE IS A CHARACTERISTIC PORE DIAMETER LARGER THAN A COMPARATIVELY SMALL VOLUME OF PORES AND IMMEDIATELY SMALLER THAN A LARGE VOLUME OF PORES. THE MERCURY INTRUSION PORE SIZE DISTRIBUTIONS INVARIABLY DISPLAY A CHARACTERISTIC PORE DIAMETER ABOVE WHICH LITTLE PORE VOLUME IS DETECTED AND IMMEDIATELY BELOW WHICH AN APPRECIABLE FRACTION OF THE TOTAL MEASURED PORE VOLUME IS INTRUDED. THIS THRESHHOLD DIAMETER DECREASED WITH INCREASING AGE AND DECREASING WATER/CEMENT RATIO. THE WATER VAPOR PORE SIZE DISTRIBUTION CURVE FOR THE 0.6 WATER/CEMENT RATIO PASTE SHOWS REMARKABLE AGREEMENT WITH THE MERCURY INTRUSION CURVES. IN ALL CASES, THE WATER VAPOR MEASURES A GREATER PORE VOLUME THAN DOES THE MERCURY AND THE DEVIATIONS ARE PRESUMED TO BE CAUSED BY RESTRICTED ENTRYWAYS INTO PORES.

  • Record URL:
  • Supplemental Notes:
    • No 31, 102 PP, 32 FIG, 8 TAB, 23 REF, 7 APP
  • Corporate Authors:

    Purdue University

    Joint Transportation Research Program
    West Lafayette, IN  United States  47907-2051

    Indiana Department of Transportation

    100 N Senate Avenue
    Indianapolis, IN  United States  46204

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • WINSLOW, D N
  • Publication Date: 1968-12-18

Media Info

  • Media Type: Digital/other
  • Edition: Final Report - Phase I
  • Features: Appendices; Figures; References; Tables;
  • Pagination: 127p

Subject/Index Terms

Filing Info

  • Accession Number: 00213811
  • Record Type: Publication
  • Report/Paper Numbers: FHWA/IN/JHRP-68/31, C-36-61E
  • Files: TRIS, USDOT, STATEDOT
  • Created Date: Oct 13 1970 12:00AM