This paper presents results from an experimental study on the effect of temperature on bond strength of I-shaped steel and concrete. Eleven concrete encased steel (CES) specimens were tested by home-made fire test furnace to evaluate bond strength at various constant high temperatures (20°C600°C). The test results showed that: (1) the trend of the bond-slip curves at high temperatures were much similar to that at room temperature. Compared with room temperature specimen, the ultimate bond load and the residual bond load of specimens at high temperatures were significantly decreased. The specimens with the higher temperature had the less ultimate bond load and residual bond load. (2) In the descending stage, the P-S curve of the specimens with higher temperatures had more flat slope. The P-S curve of the specimens at the temperatures higher than 250°C had invisible descending stage. The ultimate bond load of the specimen at 600°C left with only about 5% of that at room temperature. (3) The ultimate slippages (i.e. the slippage at the ultimate bond load) of specimens at high temperatures were larger than that at room temperature, and varied from 2 to 5 mm. (4) The calculation formulas of ultimate bond load, ultimate slippage, and residual bond load at different temperatures were presented, the constitutive equations of bond-slip at different temperatures were obtained, which will provide a reference for the fire-resistant design of concrete encased steel columns.

本文介绍了温度对工字型钢与混凝土粘结强度影响的实验研究结果。用自制的耐火试验炉对11个混凝土包裹的钢（CES）样品进行了测试，以评估在各种恒定高温（20°C600°C）下的粘结强度。测试结果表明：（1）高温下的粘滑曲线趋势与室温下的相似。与室温试样相比，高温下试样的极限粘结载荷和残余粘结载荷明显降低。温度较高的试样的极限粘结载荷和残余粘结载荷较小。（2）在下降阶段，温度较高的试样的PS曲线的斜率更大。样品在高于250°C的温度下的PS曲线具有不可见的下降阶段。样品在600°C时的极限粘结载荷仅剩室温下的5％。（3）高温下的试样极限滑移（即极限粘结载荷下的滑移）大于室温下的极限滑移，变化范围为2至5 mm。（4）给出了不同温度下的极限粘结荷载，极限滑移和残余粘结荷载的计算公式，得到了不同温度下的粘结滑移本构方程，为混凝土的耐火设计提供参考。包裹钢柱。样品在高温下的极限滑移比在室温下的滑移要大，在2到5 mm之间变化。（4）给出了不同温度下的极限粘结荷载，极限滑移和残余粘结荷载的计算公式，得到了不同温度下的粘结滑移本构方程，为混凝土的耐火设计提供参考。包裹钢柱。样品在高温下的极限滑移比在室温下的滑移要大，在2到5 mm之间变化。（4）给出了不同温度下的极限粘结荷载，极限滑移和残余粘结荷载的计算公式，得到了不同温度下的粘结滑移本构方程，为混凝土的耐火设计提供参考。包裹钢柱。