方钢管再生混凝土长柱偏心受压力学性能研究

Experimental research on mechanical behavior of recycled aggregate concrete filled square steel tubular long columns under eccentric compression loading

以长细比及偏心距为主要变化因素,对8个方钢管再生混凝土长柱试件进行偏心受压单调加载试验。通过观察试件破坏形态,利用获取的荷载-位移曲线、荷载-应变曲线及试件承载力等重要数据,分析方钢管再生混凝土长柱偏心受压工作机理,并讨论上述因素对试件极限承载力及破坏形态的影响,最后利用国内常用的钢管混凝土规范所推荐的压弯构件承载力计算方法进行承载力理论计算,并与试验结果进行对比。研究表明:方钢管再生混凝土长柱偏心受压试件的受力过程、破坏形态、变形特性等与普通钢管混凝土相似,试件承载力随长细比和偏心距的增大而减小,最终破坏形态主要为整体失稳破坏,部分试件为材料强度破坏;根据规程GJB 4142—2000所计算承载力与试验结果吻合较好。

To take slenderness ratio and eccentricity as main variable factors,eccentric compression monotonic loading test was carried out on 8 recycled aggregate concrete filled square steel tubular long columns. By observing the specimens failure modes, using load-displacement curves, load-strain curves and the bearing capacity of specimens analyzed mechanics behavior of recycled aggregate concrete filled square steel tubular long columns under eccentric compression.The influence of the test parameters on the ultimate bearing capacity and failure modes of specimens were discussed. At last,the standards for concrete filled steel tube which are wildlly used in China were used to calculate compression-bending members＇ theoretical bearing capacity. The calculation results were analyzed and compared with measured results. It is shown that the recycled aggregate concrete filled square steel tubular long columns under eccentric compression have similar characteristics to normal concrete filled steel tube columns in loading process,failure modes and deformation features. The bearing capacity of specimens decreases as slenderness ratio and eccentricity increase. The final failure mode mainly is overall instability damage,part of the specimens are materials strength failure. The bearing capacity of the specimens calculated according to the standard GJB 4142-2000 is in good agreement that with the experimental results.