1200d预应力高性能混凝土梁长期性能试验研究

Experimental Study on Long-Term Behavior of Prestressed HPC Beams for 1 200 Days

通过6根1∶5模型梁的1 200 d长期试验,对预应力高性能混凝土梁的长期性能进行了较系统的研究与分析,重点考察了预应力筋张拉方式以及截面上、下缘应力差等因素对梁长期挠曲变形、徐变应变、截面曲率、预应力筋应变增量和钢筋应变等的影响.提出了综合考虑预应力筋张拉方式以及截面应力差等多因素影响的、预应力高性能混凝土梁长期挠曲变形设计建议公式,计算结果与试验值的最大误差在10%以内.

Experimental and analytical studies are conducted to investigate long-term behavior of 6 models（1：5） of prestressed high performance concrete（HPC）beams for about 1 200 days. The research with an emphasis on the influence of tensioning methods, stress difference between upper and lower fibers of beam sections on long-term deflection, creep strain, cross-section curvature, prestressing tendon strain increment as well as strain stress of models was carried out. Calculations by using this program agree well with the test results. Long-term deflection design suggestion of prestressed HPC beams taking tensioning methods as well as stress difference between upper and lower fibers into account is suggested. The calculated values correspond well with the test results. The error is less than 10 %.