As a frequent and serious disaster, fire will cause serious damage to a building's structure when it occurs, so it is very important to study the mechanical properties of structural components after a fire. In this paper, 20 push-out tests of steel reinforced recycled aggregate concrete (SRRAC) columns subjected to a fire were conducted in order to study the bond behavior between I-steel and recycled aggregate concrete (RAC) and the fire exposure was simulated by electrical oven. After this, the change of physical and mechanical properties and the process of mechanical failure of the specimens before and after high temperature exposure were analyzed, and the influence of various parameters on the bond behaviors of SRRAC subjected to elevated temperatures was discussed. At last, the calculation formulas of bond strength were put forward. Test results show that cracks appear on the surface of specimens when the maximum temperature is >400°C, and the higher the temperature is, the more and wider the cracks are. With the increase of temperature, the bond strength of the specimen decreases significantly. When the replacement percentage of RCA is <50%, the bond strength increases continuously, on the contrary, the bond strength decreases, and the bond strength of RAC specimens is larger than that of natural aggregate concrete (NAC) specimens. The comparative analysis of specimens subjected to different temperatures demonstrates that the higher the maximum temperature the slower the development of bond damage is. At the same time, the higher the maximum temperature is, the stronger the energy dissipation capacity is.

作为频繁发生的严重灾难，火灾在发生时会对建筑物的结构造成严重破坏，因此研究火灾后结构部件的机械性能非常重要。为了研究工字钢与再生骨料混凝土（RAC）的粘结性能，本文进行了20次受火的钢筋再生骨料混凝土柱（SRRAC）的推顶试验，并通过火灾模拟了火灾暴露电烤箱。在此之后，分析了样品在高温暴露前后的物理和机械性能的变化以及机械破坏的过程，并讨论了各种参数对SRRAC在高温下的键合行为的影响。最后提出了粘结强度的计算公式。测试结果表明，当最高温度> 400°C时，试样表面会出现裂纹，温度越高，裂纹越宽。随着温度的升高，试样的粘结强度明显降低。当RCA的替换百分比<50％时，粘结强度持续增加，相反，粘结强度降低，并且RAC试样的粘结强度大于天然骨料（NAC）试样。对样品在不同温度下的比较分析表明，最高温度越高，键破坏的发生越慢。同时，最高温度越高，能量耗散能力越强。