带载状态下CFRP约束混凝土圆柱膨胀比试验研究  

EXPERIMENTAL STUDY ON THE EXPANSION RATIO OF PRELOADED CIRCULAR CONCRETE COLUMNS WITH CFRP CONFINEMENT

作　　者：何政[1] 金建平[1] 宋继广[1] 

机构地区：[1]东北大学资源与土木工程学院,沈阳110004

出　　处：《工程力学》2009年第9期145-151,169,共8页Engineering Mechanics

基　　金：国家自然科学基金项目(50778035)

摘　　要：对29根试件进行了CFRP约束素混凝土和钢筋混凝土圆柱的两阶段轴心抗压试验研究,考察了带载应力水平和截面尺寸对约束混凝土柱膨胀比的影响。试验结果表明:极限膨胀比随带载应力水平的增大先减小后增大。根据对试验数据的回归,得到了带载状态下CFRP约束混凝土圆柱的极限膨胀比影响因子,该因子以带载应力水平与约束比的比值n0/(fl/fco)为变量。在此基础上,对Teng等人建议的未带载情况膨胀比模型进行了改进,得到了可考虑带载影响的FRP约束混凝土全过程膨胀比模型,通过与试验结果比较表明,所有模型的预测效果良好。Twenty-nine circular plain and reinforced concrete columns with different preloading stress levels are axially tested. The effects ofpreloading stress and sectional dimension on expansion ratio are investigated as well. The results indicate that, as the preloading stress increases, the ultimate expansion ratios of the tested columns firstly decrease and then increase. A so-called influence factor of ultimate expansion ratio of preloaded concrete columns with CFRP confinement is put forward through the regressive analysis of those ratios. This influence factor is mathematically a function of the ratio of preloading stress over confining stress, n0/（f1/fc0）. Then, this non-dimensional factor is used to modify the model proposed by Teng et al for predicting the complete expansion ratio of CFRP-confined or unconfined concrete columns, thus the effect of preloading stress can be considered. The results from the modified model fit well with the test data.

关 键 词：CFRP片材 约束 带载应力 混凝土 柱 膨胀比 

分 类 号：TU375.3[建筑科学—结构工程] TU599