Discussion of 'Long-Term Behavior of Prestressed Composite Beams at Service Loads for One Year' by Weichen Xue, Min Ding, Chi He, and Jie Li

摘要

The discussers appreciate the authors' comprehensive work to evaluate the long-term behavior of prestressed composite beams at the service loads based on an experimental program, on which rather few tests and analytical studies (Ranzi and Bradford 2006; and Macorinia et al. 2006) have been reported. The composite beams studied were prestressed with external high-strength strands, and the long-term behavior of the beams should be influenced by concrete and strands, whose properties, such as creep and shrinkage for the concrete and stress relaxation for the strands, are time-dependent. The test results reveal the nonlinear time-dependent phenomena of composite beams, and some findings are interesting to the discussers. However, the findings are not well clarified when the results are compared and evaluated, as indicated in the following sections.