The Alm Bridge in Upper Austria, completed in October 1977, is both post-tensioned in conventional fashion, and post-compressed using a technique developed by Prof Hans Reiffenstuhl of Vienna University. Steel rods in specially developed ducts are arched to mirror the conventional tensile tendon drape, compressed and grouted to induce tension in the concrete to counteract compressive stresses that would otherwise occur. The end result is that all dead load can be carried entirely by the pre-stress, and the section has only to carry live loads. For the Alm Bridge the span/depth ratio was 30, nearly double that normally possible with pre-stressed concrete. The technique however is not cheap and it is estimated that it put the cost of the new bridge up by 30% (including development costs). The secret of the post-compression system is said to be Reiffenstuhl's duct design. /TRRL/


  • English

Media Info

  • Features: Figures; Photos;
  • Pagination: p. 22
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00184318
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Dec 29 1978 12:00AM