取代率对钢管再生混凝土短柱轴压性能退化的影响分析

Influence of Replacement Ratio on Axial Compression Performance Degradation of Recycled Aggregate Concrete-filled Steel Tube Short Column

为了揭示再生粗骨料含量对钢管再生混凝土短柱轴压性能退化的影响,以再生粗骨料取代率级差10%作为主要变化参数,分别进行了22组圆钢管试件(以直径90mm和110mm为次要变化参数)和11组方钢管试件的轴心受压试验,从组合轴压刚度退化、损伤以及耗能的角度分析了再生粗骨料取代率对其性能衰减的影响程度。研究结果表明:钢管再生混凝土短柱在非弹性阶段的退化特性大致表现为负指数函数的形式;再生粗骨料取代率较高时的轴压损伤累积比取代率较小的试件快;对于含钢率低、套箍系数小的圆钢管试件,其全过程耗能因子降低较快且变得较小;再生粗骨料取代率超过50%后,钢管再生混凝土的轴压终值耗能因子均随取代率的增加而降低。

In order to reveal the influence of content of recycled coarse aggregate on axial compression performance degradation of RAC-filled steel tube short columns, taking RCA replacement ratio grade 10% as the main variable parameter, axial compression tests for 22 groups of circular steel tube specimens （taking diameters 90 mm and 110 mm as the secondary parameter, respectively） as well as 11 groups of square steel tube specimens were carried out. The influence of recycled coarse aggregate replacement ratio on the performance degradation was analyzed by taking into account the combined axial compression stiffness degradation, damage and energy dissipation. Results show that degradation characteristics of recycled aggregate concrete-filled steel tube short columns approximately present negative exponential function form on flon-elastic stage; when RCA replacement ratio is higher, combined axial compression cumulative damage is rapider than that of specimens with lower replacement ratio; for circular steel tube specimens with low steel ratio and small ferrule coefficient, their energy dissipation factor decreases faster and becomes smaller; .when RCA replacement ratio exceeds 50%, the final value of energy dissipation factor of recycled aggregate concrete-filled steel tube decreases with the increase of replacement ratio.