Galfan‐coated steel cables are widely used in prestressed structures due to their excellent mechanical properties and corrosion resistance. Their postfire mechanical properties are important to evaluate the residual load‐bearing capability of the structures after fire. However, the research on the postfire mechanical properties of Galfan‐coated steel cables is stillscarce, especially the cable in stress state. Hence, a research based on experimental study was carried out to investigate the deterioration of mechanical properties of Galfan‐coated steel cables in stress state after experiencing elevated temperatures in this paper. Eighteen tensile tests were conducted on specimens exposed to elevated temperatures varying from 100°C to 500°C and then cooled down to ambient temperature in air. Both twisting characteristic and constant stress level of Galfan‐coated steel cables were considered in this study. The residual nominal yield strength, ultimate strength, elastic modulus, fracture strain, and stress‐strain curves of Galfan‐coated steel cables after experiencing elevated temperatures were obtained and compared with the existing researches. The results show that the postfire mechanical properties are obviously decreased when the fire temperature exceeds 300°C. Equations for the residual nominal yield strength, elastic modulus, ultimate strength, and fracture strain of the Galfan‐coated steel cables were proposed. Furthermore, a modified two‐stage Ramberg‐Osgood model for Galfan‐coated steel cables after experiencing elevated temperatures was established, which can provide reference for the safety assessment and repairment of prestressed structures after fire.

中文翻译：

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Galfan涂层钢电缆的火灾后力学性能

镀有Galfan涂层的钢缆因其优异的机械性能和耐腐蚀性而广泛用于预应力结构中。其火灾后的力学性能对于评估火灾后结构的残余承载能力很重要。但是，对镀有Galfan涂层的钢缆的火灾后力学性能的研究仍然很少，特别是处于应力状态的钢缆。因此，本文进行了一项基于实验研究的研究，以研究在高温下应力作用下的镀锌钢电缆的力学性能的下降。在暴露于100°C至500°C高温下的样品上进行了18次拉伸测试，然后在空气中冷却至环境温度。在这项研究中，考虑了镀金钢绞线的扭曲特性和恒定应力水平。获得了在高温下Galfan涂层钢缆的残余标称屈服强度，极限强度，弹性模量，断裂应变和应力-应变曲线，并与现有研究进行了比较。结果表明，燃烧温度超过300℃时，燃烧后力学性能明显下降。提出了Galfan涂层钢缆的残余标称屈服强度，弹性模量，极限强度和断裂应变的方程式。此外，还建立了经过改进的Galfan涂层钢缆在经历高温后的两阶段Ramberg-Osgood模型，