STRESS REDISTRIBUTION AND STRUCTURAL RESERVES IN PRESTRESSED CONCRETE BRIDGES

While investigating the behaviour of ageing post-tensioned multi-beam concrete bridges, the dead load stresses, directly measured by the release method, have shown highly curved profiles both over the section height and across its web and flange thicknesses. This time-dependent stress redistribution was confirmed and further explained by a recent non-linear finite element incremental model, simulating concrete creep and shrinkage effects. Under applied flexure, however, the directly measured stress variation profiles proved perfectly linear over the section height. The actual flexural reserves can thus be obtained by comparing the instantaneous stress response with the dead load stresses. Access to these reserves is relatively easy in thick-webbed box girders. The remaining prestress and the concrete cracking or softening potential can also be estimated to facilitate optimum strengthening and preventative durability measures. (A) For the covering abstract see IRRD 882313.

Language

  • English

Media Info

  • Features: References;
  • Pagination: p. 761-8

Subject/Index Terms

Filing Info

  • Accession Number: 00729514
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • ISBN: 0-419-21210-8
  • Files: ITRD
  • Created Date: Dec 26 1996 12:00AM