EXPERIMENTAL RESEARCH ON PRESTRESSING TIME-DEPENDENT LOSS OF HIGH-PERFORMANCE CONCRETE BEAMS
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摘要: 对C60高性能混凝土梁预应力长期损失进行试验研究。通过对3根无粘结预应力混凝土梁在自然环境下的收缩徐变、挠度和有效预应力的长期观测与理论分析得出:挠度的长期增大主要取决于截面上混凝土的应力分布;挠度徐变系数大于按规范计算的徐变系数,若用徐变系数计算施工阶段梁的变形,则会低估变形;预应力长期损失测量值大于理论计算值。Abstract: Experiments on prestressing time-dependent loss of C60 high-performance concrete(HPC) are carried out.By analyzing experimental results of shrinkage,creep,deflection and effective prestress of three prestressed concrete beams under natural environment,it is obtained that the increase in long-term deflection mainly depends on the sectional stress distribution of concrete.Deflection creep coefficient is larger than the one calculated by the code.It will be underestimated if creep coefficient is used to calculate the beam deflection for construction stage.The prestressing time-dependent loss in test will be greater than that in theory.
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