INVESTIGATIONS IN THE SYSTEM 3 CAO-AL203-CASO4-CAO-H20

THE QUESTIONS IN CONNECTION WITH THE CONDITIONS OF FORMATION OF ETTRINGITE INDUCED THESE EXPERIMENTAL INVESTIGATIONS IN THE SYSTEM C3A-CASO3-CAO-H20. CHEMICAL AND INFRARED SPECTROSCOPIC INVESTIGATIONS WERE CONDUCTED ON THE CAO CONTENTS OF THE TEST SOLUTION AND THE HYDRATION PRODUCTS WERE INVESTIGATED RADIOGRAPHICALLY. ETTRINGITE CRYSTALS FORM IMMEDIATELY AFTER THE ADDITION OF WATER FOR THE HYDRATION OF C3A WITH GYPSUM AND LIME. THIS WAS SHOWN BY ELECTRON MICROSCOPE AND RADIOGRAPHIC TECHNIQUES. THE REACTION VELOCITY COULD BE MEASURED BY DETERMINATION OF THE INCREASE OF THE SOLID PHASE AND BY DETERMINATION OF THE DECREASE OF THE AMOUNT OF FREE SO3 IN THE REACTION MIXTURE. IN THE FURTHER COURSE OF THE REACTION A CONSIDERABLE DECREASE IN THE REACTION VELOCITY IS OBSERVED, CAUSED BY THE FORMATION OF ETTRINGITE COVERS AROUND THE C3A GRAINS. AFTER 21 HR A SMALL, FOLLOWED BY A VERY CONSIDERABLE, INCREASE OF THE HYDRATION RATE CAN BE OBSERVED. THIS INCREASE OF HYDRATION RATE IS ESPECIALLY CHARACTERIZED BY THE CONSIDERABLE DECREASE OF THE FREE SO3 IN THE REACTION MIXTURE WHICH IS EXPLAINED BY THE CONVERSION OF THE C3A TO C4AH13, OR THE SOLID SOLUTION OF C3ACSH12 WITH C4AH13.

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/sr/sr90/90-029.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:
  • Schwiete, H E
  • Ludwig, U
  • Jager, P
• Publication Date: 1966

Media Info

• Media Type: Print
• Features: Figures; Photos; References;
• Pagination: pp. 353-367
• 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: Calcium compounds; Calcium oxide; Chemical analysis; Crash investigation; Electron microscopes; Ettringite; Forming; Gypsum; Hydration; Infrared spectroscopy; Oxides; Portland cement; Radiography; Reaction time; Rock crystals; Solutions (Chemistry); Studies; Testing
• Old TRIS Terms: Solutions
• Subject Areas: Highways; Materials; Safety and Human Factors;

Filing Info

• Accession Number: 00212460
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Dec 22 2001 12:00AM