钢骨混凝土短柱在长期轴向荷载作用下的试验研究

Abstract

钢骨混凝土柱结构在过去几十年间已得到广泛的运用。但是目前关于这种柱结构在长期荷载作用下由于徐变和收缩引起的与时间相关的力学性能研究还开展得很少。该文开展了钢骨混凝土短柱的长期轴向荷载试验研究,还进行了这些柱的极限承载力破坏试验。试验监测了由徐变和收缩引起的柱的轴向长期变形。基于该实测曲线的分析表明,采用ACI 209r-92的收缩模型和CEb-fIP90的徐变模型,利用龄期调整有效模量法可以较好地模拟钢骨混凝土柱在长期轴向荷载作用下的变形发展。经历了长期加载后的试验柱的极限承载力破坏试验还表明,长期轴向荷载对柱的轴压承载力没有显著影响。

Steel-reinforced concrete(SRC) columns have been widely used over the past few decades.However, very limited research has been conducted on the time-dependent behavior of these columns caused by creep and shrinkage under sustained loadings.This paper provides an experimental study on the long-term behavior of short SRC columns under sustained axial loadings and their ultimate axial bearing capacity.Long-term axial deformation due to shrinkage and creep of the concrete were recorded.Based on test results, time-dependent analysis of the SRC columns under sustained axial loadings using the age-adjusted effective modulus method was proved to be effective by employing the ACI 209R-92 model for the prediction of shrinkage and the CEB-FIP90 model for creep.The ultimate strength of the columns after long-term loading was also determined and results showed that the axial sustained load had no significant effect upon the axial compressive strength of SRC columns.