型钢再生混凝土偏压柱受力性能试验及承载力计算

为了研究型钢再生混凝土柱在偏心压力作用下的力学性能,设计9个试件进行偏心受压单调加载试验,考虑了再生骨料取代率、相对偏心距2个变化参数。通过试验,观察了该类新型构件的受力破坏过程及形态,获取了应力分布、变形情况、极限承载力、荷载-变形全过程曲线、再生混凝土受压破坏极限压应变值等重要数据；并分析了取代率和相对偏心距对试件极限承载力的影响规律。研究结果表明:型钢再生混凝土柱的偏压破坏过程及形态与一般型钢混凝土柱相似,根据偏心距的不同,表现为大偏心受压破坏和小偏心受压破坏两种形态,试件极限承载力随着相对偏心距的增大而减小,而再生骨料取代率的变化对承载力的影响作用不明显。基于修正平截面假定推导了型钢再生混凝土偏压柱的正截面极限承载力计算公式,计算值与试验值吻合较好。

MECHANICAL BEHAVIOR AND COMPUTED BEARING CAPACITY OF STEEL REINFORCED RECYCLED-AGGREGATE-CONCRETE COLUMNS UNDER ECCENTRIC LOADING

In order to reveal the mechanical performance of steel reinforced recycled-aggregate-concrete columns, 9 specimens were designed for eccentric compression tests. Two variable parameters and a recycled coarse aggregate replacement ratio and relative eccentricity are taken into consideration. Based on the test, the stress distribution, ultimate bearing capacity, load-strain curve and other important data are obtained. Test results showed that the damage process and failure mode of a steel reinforced recycled-concrete column was similar to those occurred in the conventional steel reinforced concrete columns. It is demonstrated that the failure mode includes large eccentric compression failure and small eccentric compression failure, and the ultimate bearing capacity of composite columns decreases with the increase of its relative eccentricity, while the influence of the variable replacement ratio of the recycled coarse aggregate on the bearing capacity is negligible. The formulas of the ultimate bearing capacity for the eccentrically loaded column are proposed by the basis of experimental data. The computed results agree well with test results.