BEEFING UP THE MIX

Recent developments in additives have made significant advances in the application, strength, uses and cost-effectiveness of shotcrete linings. They include a wet mix system which involves premixing the concrete before conveying it through the hose and projecting it with air at the nozzle used when rock must be stabilized quickly after an excavation cycle; a dry mix system using a cement-based, polymer modified, one component repair mortar containing silica fume and high range water reducing agents formulated for use without accelerators to give thick layer repairs with rapid strength gain; addition of steel fibers to the fresh mix to reinforce concrete to develop lighter and stronger materials; addition of silica fume to steel fibre-reinforced concrete to improve the adhesive and cohesive properties of the shotcrete; and polyethylene sheets for protection against fires.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/0041414X
• Corporate Authors:

  Morgan-Grampian (Construction Press) Limited

  Morgan-Grampian House, 30 Calderwood Street
  London SE18 6QH,   England 
• Authors:
  • Lock, J
• Publication Date: 1989-7

Media Info

• Features: Photos;
• Pagination: p. 57-58
• Serial:
  • Tunnels & Tunnelling International
  • Volume: 21
  • Issue Number: 7
  • Publisher: Progressive Media Markets, Ltd
  • ISSN: 0041-414X

Subject/Index Terms

• TRT Terms: Additives; Ethylene resins; Shotcrete; Silica; Steel; Tunnel lining
• Uncontrolled Terms: Polyethylene
• Subject Areas: Construction; Geotechnology; Highways; Materials; Public Transportation;

Filing Info

• Accession Number: 00486535
• Record Type: Publication
• Files: TRIS
• Created Date: Aug 31 1989 12:00AM