外套圆钢管自密实混凝土加固RC方柱偏压性能试验研究及有限元分析

Research on behavior of RC square column strengthened with self-compacting concrete filled circular steel jacket under eccentric loading

对4根外套圆钢管自密实混凝土加固钢筋混凝土方柱试件进行偏心受压试验,试验结果表明:圆钢管混凝土加固方柱的破坏形态为弯曲型破坏,其承载力在达到极限以后能维持在一个相对高的荷载值,具有良好的延性,并且随着偏心率的增加,加固柱挠度增大,承载力降低。采用有限元软件ABAQUS对加固柱进行计算,并将有限元计算的承载力、荷载-跨中挠度曲线和荷载-应变曲线与试验结果进行对比,对比结果表明有限元计算结果与试验结果吻合良好。在此基础上,分析了后浇混凝土强度、钢管壁厚、偏心距对加固柱偏压性能的影响,并得到加固柱的轴力-弯矩相关曲线,可用于计算任意偏心距下加固柱的受压受弯承载力。

Four RC square columns strengthened with self-compacting concrete filled circular steel jacket were tested under eccentric loading. The results show that the failure modes of strengthened columns are flexural failure and the bearing capacity can remain at a relatively high level after the limit load,showing a good ductility. With the increase of eccentricity ratio,the deflection of the strengthened column is greater and the bearing capacity is lower. Moreover,ABAQUS was used to calculate the bearing capacity,load-middle span deformation curves and load-strain curve of the strengthened column. Calibration of the calculated results against the test results shows that the calculated results are in good agreement with test results. Based on the verified model,the influences of the concrete strength,the steel tube wall thickness and the eccentricity ratio on the mechanical properties of the columns were analyzed. A load-bending moment curve was obtained to calculate the ultimate bearing capacity and bending moment of the reinforced column under arbitrary eccentricity.