Deflections of precast pretensioned beams

Many medium span bridges are built with precast pretensioned beams. The majority of the bridges built in Australia are up to 35m span and the most common of these is in Super T form. The AS5100 code requires these beams to be built with no sag. However even when the provisions of the code have been applied, despite predictions of long term hog and adequate strength, beams of some bridges have sagged. Why does this happen? This paper explores, by way of actual examples, the reasons why some bridge beams, under some conditions, do not behave as the code predicts. It considers effects of creep and differential shrinkage, the effects of prestressing and non-prestressed reinforcement, and the influence of environmental conditions. (a) For the covering entry of this conference, please see ITRD abstract no. E214936.

Language

  • English

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Filing Info

  • Accession Number: 01051012
  • Record Type: Publication
  • Source Agency: ARRB
  • Files: ITRD, ATRI
  • Created Date: Jun 11 2007 1:08PM