Abstract Thin-walled steel tube confined reinforced concrete columns are new-type composite members and the static and seismic performance of these columns have been extensively investigated in recent decades. There are, however, very limited studies on the fire behaviour of the steel tube confined reinforced concrete stub columns subjected to axial compression. In this paper, experimental and numerical studies on the fire response of steel tube confined reinforced concrete stub columns under axial compression are presented. A total of eight specimens with varying wall thicknesses of steel tube and load ratios were tested to failure under the ISO-834 standard fire. Temperature distribution, axial deformation, failure modes, and fire duration were recorded in the fire tests. Finite element (FE) models were established using ABAQUS to estimate the fire behaviour and the models were validated by comparing with the measured results. Parametric studies were then performed on the fire resistance of thin-walled steel tube confined reinforced concrete stub columns and the considered parameters include diameter of steel tube, wall thickness of steel tube, load ratio, reinforcement ratio, material strength, and concrete cover thickness. The studies show that the load ratio and diameter of steel tube are two key factors governing fire resistance of thin-walled steel tube confined reinforced concrete stub columns. Based on test and numerical results, a design approach was proposed to predict the temperature distribution and loading capacity of thin-walled steel tube confined reinforced concrete stub columns under ISO-834 standard fire.

中文翻译：

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薄壁钢管约束钢筋混凝土短柱轴压受火性能

摘要 薄壁钢管约束钢筋混凝土柱是一种新型组合构件，近几十年来对这些柱的静力和抗震性能进行了广泛的研究。然而，关于受轴向压缩的钢管约束钢筋混凝土短柱的防火性能的研究非常有限。在本文中，介绍了钢管约束钢筋混凝土短柱在轴压下的火灾响应的试验和数值研究。在 ISO-834 标准火灾下，对总共八个具有不同钢管壁厚和载荷比的试样进行了失效测试。在火灾试验中记录了温度分布、轴向变形、失效模式和火灾持续时间。使用ABAQUS建立有限元（FE）模型来估计火灾行为，并通过与测量结果进行比较来验证模型。然后对薄壁钢管约束钢筋混凝土短柱的耐火性能进行了参数研究，考虑的参数包括钢管直径、钢管壁厚、荷载比、配筋率、材料强度和混凝土覆盖层厚度。研究表明，荷载比和钢管直径是影响薄壁钢管约束钢筋混凝土短柱耐火性能的两个关键因素。根据测试和数值结果，