中文摘要：

通过9根加固钢筋混凝土圆形短柱（8根钢管自密实混凝土复合加固柱,1根扩大截面加固柱）和1根钢筋混凝土原柱的偏心受压试验,对不同方法加固钢筋混凝土圆形短柱的承载力、刚度和延性进行研究,分析偏心距、钢管壁厚和自密实混凝土强度对复合加固短柱偏压性能的影响。试验结果表明：复合加固短柱的承载力与延性均优于扩大截面加固柱;减小偏心距或增加钢管壁厚均能显著提高复合加固柱的承载力与延性;改变自密实混凝土强度,复合加固柱承载力与延性变化不明显。在确定钢材与新旧混凝土本构关系的基础上,利用纤维模型法对复合加固短柱偏压性能进行参数分析。研究结果表明：增加钢管壁厚或提高屈服强度,N/Nu-M/Mu相关曲线往内收拢;增大外扩截面直径或提高自密实混凝土强度,N/Nu-M/Mu相关曲线往外凸出。

英文摘要：

According to the tests of 9 strengthened reinforced concrete （RC） columns （1 RC column strengthened by the enlarging cross-section method and 8 RC columns strengthened with self-compacting concrete （SCC） filled steel tubes） and 1 normal RC column under eccentric loading, the bearing capacity, stiffness and ductility of RC columns strengthened by different retrofitting methods were investigated. The influence of eccentricity, steel ratio and compressive strength of SCC on RC columns strengthened with SCC filled steel tubes were also analyzed. Test results show that the bearing capacity and ductility of composite strengthened columns are significantly better than those of the columns strengthened by the enlarging cross-section method. As the eccentricity decreases or the steel ratio increases, the composite strengthened columns show significant increase in the bearing capacity and ductility. The bearing capacity and ductility of composite strengthened columns do not change obviously as SCC strength changes. Based on the stress-strain relationship for concrete and steel, the fiber model is applied to conduct parametric analysis. Results indicate that the N/Nu-M/Mu curves will shrink inwards along with the increment in the steel yield strength or the sectional steel ratio, and expand outwards with the increment in SCC strength or the external diameter of the cross-section of the RC columns.