NITROGEN SORPTION MEASUREMENTS AND SURFACE AREAS OF HARDENED CEMENT PASTES

SURFACE AREA BY NITROGEN ADSORPTION AND NONEVAPORABLE WATER WERE DETERMINED ON HARDENED CEMENT PASTES OF FOUR WATER-CEMENT RATIOS, RANGING FROM 0.251 TO 0.501, AND FOUR AGES, RANGING FROM 1 DAY TO 180 DAYS. WATER-CEMENT RATIO MADE VERY LITTLE DIFFERENCE IN THE SURFACE AREA OF HARDENED PASTES AT 1 DAY, BUT WITH PASTES AT LATER AGES, EVIDENCE SUGGESTS THAT SURFACE AREA MAY REACH A LIMITING VALUE WHICH IS A FUNCTION OF THE ORIGINAL WATER-CEMENT RATIO. THE RATIO OF SURFACE AREA BY NITROGEN ADSORPTION TO NONEVAPORABLE WATER WAS NOT CONSTANT BUT INCREASED WITH INCREASING HYDRATION IN PASTE OF WATER-CEMENT RATIO 0.501 AND CHANGED VERY LITTLE OR EVEN DECREASED SLIGHTLY IN PASTE OF WATER- CEMENT RATIO 0.251. THE DEGREE OF SUBDIVISION OF THE PASTE DURING DRYING EXERTED A SIGNIFICANT EFFECT ON THE MEASURED SURFACE AREA EXCEPT FOR SPECIMENS OF HIGH WATER-CEMENT RATIO MEASURED EARLY IN THE HYDRATION PROCESS. IN MOST CASES PASTES WHICH WERE DRIED AS CYLINDERS, 1/2 IN. IN DIAMETER AND 1/2 IN. LONG, HAD LOWER SURFACE AREAS THAN SPECIMENS OF THE SAME PASTES WHICH WERE CRUSHED TO PARTICLE SIZES LESS THAN 1 MM BEFORE DRYING. THE SORPTION ISOTHERM AND CALCULATED PORE SIZE DISTRIBUTION OF A PASTE AFTER DIFFERENT DRYING TREATMENTS WERE ALSO DETERMINED. /AUTHOR/

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/sr/sr90/90-010.pdf
• Supplemental Notes:
  • Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
• Corporate Authors:

  Highway Research Board (HRB)

  Washington, DC   
• Authors:
  • Hunt, C M
• Publication Date: 1966

Media Info

• Features: Figures; References; Tables;
• Pagination: pp 112-122
• Monograph Title: Symposium on structure of Portland cement paste and concrete
• Serial:
  • Highway Research Board Special Report
  • Issue Number: 90
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Adsorption; Cement; Concrete hardening; Hardness; Hydration; Isotherms; Measurement; Nitrogen; Pastes; Pore space; Sorption; Surfaces; Water cement ratio
• Uncontrolled Terms: Nonevaporable water; Surface area
• Old TRIS Terms: Determination
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 00212283
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Nov 18 1994 12:00AM