TENDON STRESS AND FLEXURAL STRENGTH OF EXTERNALLY PRESTRESSED BEAMS

Externally prestressed beams are structural concrete members wherein the prestressing tendons are placed outside the concrete section. The flexural response of an externally prestressed beam has been commonly equated to that of a beam with internal unbonded tendons, for which most of the prior analytical studies give the stress in the tendon at ultimate flexure limit state as a function of the span-depth ratio of the beam. However, it is shown in this paper that the span-ratio has insignificant effect on tendon stress at ultimate flexure in externally prestressed beams. Tests conducted on prototype beams confirmed analytical results. Therefore, a modified bond reduction coefficient is proposed for the evaluation of flexural strength of externally prestressed beams based on strain compatibility and force equilibrium. Theoretical calculations based on the bond reduction coefficient and accounting for 2nd-order effects were found to agree with the test results.

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  • English

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  • Accession Number: 00963160
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Sep 4 2003 12:00AM