In order to study the mechanical properties of Recycled Aggregate Concrete-filled Square Steel Tubular (RACFSST) stub columns after fire exposure, a total of 37 specimens were exposed to heating temperatures and cooling phases (including natural cooling and water spray cooling), and the axial compression tests were subsequently conducted. The failure modes, axial load versus deformation curves, and residual bearing capacity of specimens with different cooling methods were obtained. The results show that all specimens suffered steel tube tearing and local buckling. The overall change law of the axial load versus displacement curves was significantly affected by the heating temperature and cooling method, whereas not obviously affected by the replacement ratio of RCA. Compared with natural cooling, the residual bearing capacity of specimens decreased after water spray cooling, with a maximum decrease of 38.17%. A simplified formula for calculating the residual bearing capacity which can take into account the influence of RAC ratio, heating temperature, and cooling method of reclaimed aggregate was proposed.

为了研究暴露在火中的再生骨料方钢管短管柱（RACFSST）的力学性能，共有37个试样暴露于加热温度和冷却阶段（包括自然冷却和喷水冷却），并且随后进行了轴向压缩试验。获得了不同冷却方法的试样的破坏模式，轴向载荷与变形曲线以及残余承载能力。结果表明，所有试样均遭受钢管撕裂和局部屈曲。轴向载荷与位移关系曲线的总体变化规律受加热温度和冷却方法的影响很大，而不受RCA的置换率影响明显。与自然冷却相比，喷水冷却后，试样的残余承载力下降，最大值下降了38.17％。提出了一种简化的计算剩余承载力的公式，该公式可以考虑RAC比率，加热温度和再生骨料的冷却方法的影响。