基于CT扫描技术矿渣微粉改良黄土孔隙特性的试验研究

Experimental study on improving loess pore properties by slag powder based on CT scanning technology

【目的】随着黄土地区基础设施的大力开发及减碳理念的不断深化,迫切需要使用环保材料解决黄土承载能力低、孔隙率大等问题。【方法】使用不同掺量矿渣微粉对黄土进行改良,并利用工业CT仪对矿渣微粉黄土进行微观试验,从孔隙分布、形态、大小等角度进行分析,研究矿渣微粉对黄土孔结构的影响,从而为黄土力学性能变化提供参考。【结果】结果显示:掺量为15%时,黄土孔隙分形维数最小值为0.65,孔隙丰度主要集中在0~2之间,孔隙结构较为简单;掺量为5%、10%、15%、20%的矿渣微粉黄土孔隙率较素黄土分别下降14.69%、34.18%、73.42%、45.51%。【结论】结果表明:矿渣微粉掺入可有效改变黄土孔隙大小、分布、形态,使黄土孔隙结构趋于简单,利于黄土力学性能提升。适量矿渣微粉可有效降低孔隙直径,同时孔隙角度分布趋于均匀。

[Objective]With the vigorous development of infrastructure in loess areas and the deepening of the concept of carbon reduction,there is an urgent need to use environmentally friendly materials to solve the problems of low bearing capacity and large porosity of loess.[Methods]In this paper,the loess was improved using different dosing amounts of slag micronized powder,and microscopic tests were conducted on slag micronized loess using an industrial CT instrument to analyze the pore distribution,mor-phology and size to study the effect of slag micronized powder on the pore structure of the loess,so as to provide a reference for the change of the mechanical properties of the loess.[Results]The result show that the minimum pore fractal dimension of the loess is 0.65 at 15%doping,the pore abundance is mainly concentrated between 0~2,and the pore structure is relatively sim-ple.The porosity of 5%、10%、15%and 20%slag micronized powder decreased by 14.69%,34.18%,73.42%and 45.51%respectively compared with that of plain loess.[Conclusion]The test result show that the addition of slag powder can effectively change the pore size,distribution and shape of loess,make the pore structure of loess tend to be simple,and improve the mechanical properties of loess.The appropriate amount of slag micronized powder can effectively reduce the pore diameter,while the pore angle distribution tends to be more uniform.