混掺纤维自密实混凝土压敏性分析

Analysis of pressure sensitivity of hybrid fiber self-compacting concrete

在自密实混凝土中加入钢纤维及碳纳米管纤维等多元混杂纤维,在保证自密实混凝土力学性能的同时,使其具备良好的压敏性能。研究了这种混杂纤维自密实混凝土试件通电极化时间受构件含水率和尺寸的影响情况,以及在循环荷载作用下的压敏性能,并与单掺碳纳米管纤维的试件进行压敏性对比。试验结果表明:降低含水率可以有效减少极化时间,随着试件尺寸的增大,所需的极化时间会延长,但此时电阻率值较小,整体变化范围也较小,极化效果更佳;在循环荷载作用下,这种混杂纤维自密实混凝土会有明显的压敏性,且电阻率变化的可恢复性优于碳纳米管纤维自密实混凝土。

By adding the steel fiber and carbon nanotube fiber into the self-compacting concrete, the concrete presents satisfactory pressure-sensitive property after the guarantee of the mechanical properties of self-compact-ing concrete. In this paper, the effect of the polarization time on the water content and size of the component and the pressure-sensitive properties of the self-compacting concrete specimens with hybrid fibers was studied, and the pressure-sensitive properties were compared with those of the specimens with single carbon nanotube fibers.The experimental results show that reduction of water content can effectively reduce the polarization time;with the increase of specimen size, the required polarization time will be prolonged, but at this time, the resistivity value is small, the overall change range is also small, and the polarization effect is better;under cyclic loading,this kind of hybrid fiber self-compacting concrete has obvious pressure sensitivity, and the recoverability of re-sistivity change is better than that of the carbon nanotube fiber self-compacting concrete.