Carbon Fibre Reinforced Polymers (CFRP) have been used as a potential strengthening material due to the many advantages they possess over conventional strengthening materials in recent times. Their successful applications in strengthening concrete columns have also led to CFRP being used as an external strengthening material in steel columns. However, the lack of knowledge of the fire performance characteristics of CFRP has hindered the CFRP usage in steel columns, which require structural fire ratings. Therefore, this two phase experimental investigation was aimed at investigating the effect of fire on the structural performance of CFRP strengthened short Square Hollow Section (SHS) steel columns. In the first phase, CFRP strengthened short SHS columns were exposed to steady state fire conditions and tested under axial compression until failure. The test results exhibited a severe degradation of the ultimate axial compression capacity beyond the glass transition temperature of the adhesive (66 °C) and showed that the effect of CFRP has diminished completely at 225 °C. In the second phase, CFRP strengthened short SHS columns were insulated with a spray applied insulation material and exposed to standard fire under three load conditions. The standard fire test results showed that the CFRP strengthened and insulated columns were able to achieve more than 60 min of fire rating under 0.2 load ratio suggesting satisfactory fire resistance level. This paper presents the details of the investigation and its results.

由于碳纤维增强聚合物（CFRP）与传统的增强材料相比具有许多优势，因此碳纤维增强聚合物（CFRP）已被用作潜在的增强材料。它们在钢筋混凝土柱中的成功应用还导致CFRP被用作钢柱中的外部增强材料。但是，对CFRP防火性能特性的了解不足，阻碍了CFRP在需要结构防火等级的钢柱中的使用。因此，这两个阶段的实验研究旨在研究火灾对CFRP增强的短方形空心截面（SHS）钢柱结构性能的影响。在第一阶段中，CFRP加固的SHS短柱暴露于稳态火灾条件下，并在轴向压缩下进行测试直至失效。测试结果显示，超过粘合剂的玻璃化转变温度（66°C），最终轴向压缩能力严重降低，并且表明CFRP在225°C时的作用已完全减弱。在第二阶段中，CFRP加固的SHS短柱用喷涂的绝缘材料绝缘，并在三种载荷条件下暴露于标准火焰下。标准的防火测试结果表明，在0.2的负载比下，CFRP加固和隔热柱能够达到60分钟以上的防火等级，表明其具有令人满意的防火等级。本文介绍了调查的细节及其结果。