钢管混凝土短柱冻融循环作用后轴压性能试验研究

Experimental study on axial compression performance of CFST stub column after freeze-thaw cycle

为研究冻融循环作用后钢管混凝土柱的力学性能,根据冻融循环次数、混凝土强度等级以及加载方式的不同等参数变化,进行了4组共20个钢管混凝土短柱的轴压试验。结果表明,冻融循环次数对短柱的主要破坏模式没有影响,不同加载方式和套箍系数对短柱的破坏模式影响较大,其中套箍系数是影响短柱极限承载力的主因。当核心混凝土强度较低时,随着冻融循环次数的增加,延性系数降低;而冻融循环次数对高强度核心混凝土构件的延性系数无明显影响。上述研究成果可为寒冷地区遭受冻融劣化的钢管混凝土短柱的极限承载力设计以及加固维护提供试验数据支持。

In order to study the mechanical properties of concrete-filled steel tubular columns after freeze-thaw cycle, based on the changes of freeze-thaw cycle times, concrete strength grade and loading mode, the axial compression tests of 4 groups of 20 concrete-filled steel tubular short columns are carried out. The experimental results indicate that the number of freeze-thaw cycles has no effect on the main failure mode of short columns, and different loading methods and hoop coefficient have a great influence on the failure mode of short columns, among which the hoop restraint coefficient is the main factor affecting the ultimate bearing capacity of short columns. When the strength of core concrete is low, the ductility coefficient decreases with the increase of freeze-thaw cycles;The number of freeze-thaw cycles has no significant effect on the ductility coefficient of high-strength core concrete members. The research results can provide experimental data support for the ultimate bearing capacity design, reinforcement and maintenance of concrete-filled steel tubular short columns subjected to freeze-thaw deterioration in cold areas.