INVESTIGATION OF RESISTANCE OF CEMENT PASTE TO SULFATE ATTACK

TESTS INVESTIGATED THE EFFECT OF CEMENT PASTE DENSITY ON REACTION COURSE PARTLY BY MICROSCOPIC EXAMINATION OF THIN SECTIONS FROM THE TEST SPECIMENS AND PARTLY BY DETERMINATION OF SULFATE CONSUMED. THE EFFECT OF THE METAL IONS ON THE COURSE OF THE REACTION WAS ALSO INVESTIGATED BY STORING TEST SPECIMENS IN SODIUM SULFATE, MAGNESIUM SULFATE, FERROUS SULFATE, AND FERRIC SULFATE. THE TEST SPECIMENS CONSISTED OF CEMENT PASTE CUBES WITH AN EDGE LENGTH OF 25 MM. THREE DIFFERENT WATER CEMENT RATIOS WERE USED AND AFTER 7 DAYS CURING IN WATER, THE CUBES WERE STORED IN 0.07 MOLAR SOLUTIONS OF EACH OF THE FOUR SALTS. THE SOLUTIONS WERE CHANGED EACH MONTH TO KEEP THE CONCENTRATIONS APPROXIMATELY CONSTANT. AFTER THE SPECIMENS WERE STORED FOR ABOUT 2 MONTHS, SYSTEMATIC DETERMINATION OF THE SULFATE CONSUMPTION COMMENCED. THERE WAS A STRONG INCREASE IN THE TOTAL SULFATE CONSUMPTION IN THE SERIES /SODIUM SULFATE, MAGNESIUM SULFATE AND FERROUS SULFATE/ BUT IN TIME DIFFERENCES BETWEEN THE SOLUTIONS BECAME APPARENT. MICROSCOPIC EXAMINATION OF THE THIN SECTIONS SHOWED GYPSUM AS THE PREDOMINANT SULFATE REACTION PRODUCT. ETTRINGITE WAS FOUND PREDOMINANTLY IN SPECIMENS THAT HAD BEEN STORED IN SODIUM SULFATE. THE FOLLOWING CONCLUSIONS ARE DRAWN' /1/ THE AGGRESSIVENESS OF THE SOLUTIONS INCREASES FROM SODIUM SULFATE, OVER MAGNESIUM SULFATE, TO FERROUS SULFATE, /2/ THE RESISTANCE OF THE CEMENT PASTE CAN BE IMPROVED BY INCREASING ITS DENSITY, AND /3/ THIN-SECTION EXAMINATIONS SHOW THAT ETTRINGITE IS RARELY FORMED IN SUFFICIENT QUANTITIES TO CAUSE CRACK FORMATIONS. REFERENCES' THE DETERMINATION OF NONEVAPORABLE WATER IN HARDENED PORTLAND CEMENT PASTE, L. E. COPELAND, J. C. HAYES, ASTM BULL, V. 194, PP 70-74, 1953.

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/hrr/1966/113/113-006.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
• Authors:
  • Nielsen, Jorgen
• Publication Date: 1966

Media Info

• Media Type: Print
• Features: Figures; References;
• Pagination: pp 114-117
• Monograph Title: Symposium on Effects of Aggressive Fluids on Concrete
• Serial:
  • Highway Research Record
  • Issue Number: 113
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Cement; Crash investigation; Density; Ettringite; Gypsum; Ions; Iron compounds; Magnesium compounds; Metals; Microscopy; Pastes; Sodium sulfate; Specimens; Studies; Sulfate resisting cement; Sulfates; Water cement ratio
• Old TRIS Terms: Reaction; Resistance
• Subject Areas: Highways; Materials; Safety and Human Factors;

Filing Info

• Accession Number: 00211965
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Dec 12 1994 12:00AM