MINIMIZATION OF LEACHING OF SHOTCRETE BY ADMIXTURES

In tunnels built with the New Austrian Tunnelling Method the shotcrete shell is often in contact with ground-water. Depending on the amount and type of water, chemical compounds in the shotcrete are dissolved and transported into the drainage pipes and the main outfall. It was found that as well as Ca(OH)2, the alkalies in the shotcrete are responsible for the degree of leaching. Therefore the accelerators needed for such shotcretes, which mostly are based on alkalies, have to be reduced as much as possible. This can be done sufficiently if silica fume is used in connection with slag cement to make the shotcrete sticky enough, so that it adheres to the cracks.

• Corporate Authors:

  American Concrete Institute

  P.O. Box 19150, Redford Station, 22400 Seven Mile Road
  Detroit, MI  United States  48219
• Authors:
  • Breitenbucher, R
  • Springenschmid, R
  • Dorner, H W
• Conference:
  • Fly Ash, Silica Fume, Slag, and Natural Pozzolans in Concrete. Fourth International Conference
  • Location: Istanbul, Turkey
  • Date: 1992-5-3 to 1992-5-8
• Publication Date: 1992

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 781-793
• Serial:
  • Volume: 1

Subject/Index Terms

• TRT Terms: Accelerating agents; Alkali; Calcium hydroxide; Cement; Leaching; Shotcrete; Silica fume; Tunneling
• Identifier Terms: New Austrian Tunneling Method
• Old TRIS Terms: Alkalies
• Subject Areas: Bridges and other structures; Highways; Materials; I32: Concrete;

Filing Info

• Accession Number: 00624333
• Record Type: Publication
• Report/Paper Numbers: SP-132
• Files: TRIS
• Created Date: Oct 15 1993 12:00AM