A method for the analysis of time-dependent deformations in a continuous posttensionedconcrete girder is presented. The creep and shrinkage properties of theconcrete and the relaxation of the steel can be varied, as can friction betweenstrands and ducts. Recommendations are made for estimating long-term prestresslosses for structures post-tensioned with either stress-relieved or low-relaxationstrands.Large changes in stress distributions were found to occur at cross sections, andsubstantial changes in the moment distribution can occur, especially in composite structures. These changes may occur even when there is only a small change in thesteel force, and consequently the changes in concrete stress with time may not beclosely related to the changes in steel stress.
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