Xu Aimin, Liu Dewei, Fan Jiuhong, Di Jin, Wang Jie, Qin Fengjiang
Ningbo High-Grade Highway Construction Management Center, Ningbo 315192, China.
Sichuan Shudao New System Rail Group Co., Ltd., Chengdu 610047, China.
Materials (Basel). 2024 Nov 13;17(22):5538. doi: 10.3390/ma17225538.
Concrete-filled steel tubes (CFST) are widely used due to their high strength, ductility, and energy dissipation capacity. However, gaps in between core concrete and steel tube adversely affect the mechanical performance of structures, thereby compromising the safety of the building. In this paper, four concrete-filled steel tube specimens with spherical-cap gaps were designed, and quasi-static tests were conducted to investigate the impact of gap depth on the seismic performance of concrete-filled steel tube columns. The test results indicate that the gap reduced the cumulative energy dissipation and initial stiffness of concrete-filled steel tubes. The gap weakened the compressing effect on the steel tube exerted by the expansion of core concrete, leading to premature yielding of the steel tube. As the gap's depth increased from 0 mm to 30 mm, the load-bearing capacity and ductility of the concrete-filled steel tube columns decreased by 24.86% and 21.7%, respectively. This research quantified the extent to which gaps weaken the seismic performance of CFST columns, and the reduction coefficients of bearing capacity under different gap ratios were provided. This contributes to enhancing structural safety and lays a foundation for further research.
钢管混凝土（CFST）因其高强度、延性和能量耗散能力而被广泛应用。然而，核心混凝土与钢管之间的间隙会对结构的力学性能产生不利影响，从而危及建筑物的安全。本文设计了四个带有球冠间隙的钢管混凝土试件，并进行了拟静力试验，以研究间隙深度对钢管混凝土柱抗震性能的影响。试验结果表明，间隙降低了钢管混凝土的累积能量耗散和初始刚度。间隙削弱了核心混凝土膨胀对钢管的挤压作用，导致钢管过早屈服。随着间隙深度从0mm增加到30mm，钢管混凝土柱的承载能力和延性分别降低了24.86%和21.7%。本研究量化了间隙削弱钢管混凝土柱抗震性能的程度，并给出了不同间隙比下的承载力折减系数。这有助于提高结构安全性，并为进一步研究奠定基础。
