【摘要】 针对传统改性材料粉煤灰、新型改性材料纳米粘土和纳米硅溶胶,进行改性黄土的激光粒度分析、电镜扫描分析、工业CT扫描分析和BET比表面积分析实验,从微观角度探讨改性材料对黄土结构、孔隙及比表面积等方面的影响。结果表明:随着3种改性材料的掺量由1%、3%到7%,黄土颗粒间的填充物明显增多,架空孔隙逐渐减少;掺量为7%的3种改性黄土孔隙率的降低率依次为10.99%,15.10%和30.84%,黄土比表面积的增加率依次为15.02%,46.15%和68.22%。通过孔隙数量及体积分布可知,这是因为改性材料将黄土中的大中孔隙转化为比表面积更大的小孔隙。添加纳米粘土的黄土颗粒的表面及边缘更为粗糙多孔,且纳米粘土对于黄土中占大多数体积的中孔隙的填充作用较强。研究结果为后续污染物在改性黄土中的吸附及迁移规律的研究奠定了基础,为黄土地基改性处理技术的发展提供了理论依据。更多还原

【Abstract】 Aiming at the traditional modified material of fly ash,new modified materials of nano clay and nano silica,the laser particle size analysis,scanning electron microscope analysis,industrial CT scanning analysis and BET specific surface area analysis experiments of modified loess were carried out,and the effects of modified materials on the structure,pore and specific surface area of loess was discussed.The results show that:with the content of three kinds of modified materials from 1%,3% to 7%,the filling material between loess particles increases obviously,and the overhead pores decrease gradually;the reduction rates of porosity of three kinds of modified loess with the content of 7% are 10.99%,15.10% and 30.84%,respectively,and the increase rates of specific surface area of loess are 15.02%,46.15%and 68.22%,respectively. According to the number and area distribution of pores,it can be concluded that this is because the modified materials transform the large and medium pores in the loess into small pores with larger specific surface area. The surface and edge of loess particles added with nano-clay are more rough and porous,and the filling effect of nano-clay on the mesopores which occupy the majority of the loess area is stronger. The results laid a foundation for the subsequent study on the adsorption and migration of pollutants in the modified loess and provided a theoretical basis for the development of the modified loess foundation treatment technology.更多还原