掺纳米二氧化硅不锈钢圆管混凝土短柱高温后轴压力学性能试验研究

RESEARCH ON THE MECHANICAL PROPERTIES FOR SHORT COLUMNS OF NANO-SILICA CONCRETE FILLED STAINLESS STEEL CIRCULAR TUBE UNDER AXIAL COMPRESSION AFTER HIGH TEMPERATURE ACTION

通过对在混凝土中掺加不同掺量纳米SiO2的不锈钢圆管混凝土短柱在不同高温后的轴压试验,分析纳米SiO2掺量和高温对试件轴压承载力和破坏模式的影响,得到了荷载-位移曲线及荷载-应变曲线。研究结果表明:温度和纳米SiO2掺量对不锈钢圆管混凝土短柱的破坏模式影响较小。纳米SiO2不锈钢圆管混凝土短柱的轴压承载力、初始刚度及延性系数随温度的升高而降低,纳米SiO2掺量对不锈钢圆管混凝土短柱的轴压承载力影响呈现出离散性。当纳米SiO2掺量为1%时,不锈钢圆管混凝土短柱的轴压承载力最高,且随着纳米SiO2掺量的增加,试件的轴压承载力降低。温度对不锈钢圆管混凝土短柱的轴压承载力的影响随着纳米掺量的增加而增大。

Nine short columns of concrete filled stainless steel circular tube(CFSSCT) with different nano-SiO2 contents and after different temperatures action were tested to investigate the effects of nano-SiO2 content and temperature on axial compressive capacity and failure mode. This paper presented the load-displacement curves and load-strain curves. The results showed that nano-SiO2 content and high temperature had little effect on the failure mode of the CFSSCT short columns;the axial compressive capacity, initial stiffness and ductility factor of the short columns of CFSSCT decreased with the increase of temperature. The effect of nano-SiO2 content on the axial compressive capacity for the short column of CFSSCT was discrete. When the content of nano-SiO2 was 1%, the axial compressive capacity was the highest, and the axial compressive capacity decreased with the increase of the content of nano-SiO2. The effect of temperature on the axial compressive capacity increased as the content of nano-SiO2 increased.