The properties required of a support material for underground tunnels are discussed and, because concrete is both economical and easy to apply, a number of new reinforcing materials for concrete are examined with particular reference to these properties. From about thirty tests on different types of reinforced concrete, it is concluded that the addition of polymer to a concrete does not seem to influence the concrete's post-failure behavior, and the only benefit to be achieved by this addition is to increase its flexibility (or to decrease it, depending on the polymer). Steel fibers tend to increase both the strength and stiffness of the concrete, but polypropylene fibers, although having definite load-carrying capacities, provide nonstable failure, also known as brittle failure. The best result is obtained for concrete reinforced with steel wire: the post-cracking strength is very good and is maintained for a considerable deformation.

  • Corporate Authors:

    South African Institute of Mining and Metallurgy

    Box 61019
    Marshalltown, Transvaal,   South Africa 
  • Authors:
    • McChesney, M
  • Publication Date: 1976-12

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00159490
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Files: TRIS
  • Created Date: Aug 31 1977 12:00AM