电场改性水玻璃固化黄土机理研究

利用正交和单因素控制实验对电场改性水玻璃加固黄土进行了研究,并通过化学组成、矿物成分和微观结构分析探讨了电场改性水玻璃加固黄土的机理。结果表明:通电电压越高,通电时间越长,改良土体的无侧限抗压强度越大;土体强度随Na2O含量、模数的增长先减小后增大,存在下极值点;X射线衍射图中出现非晶质物相峰群,随着Na2O含量的增加,非晶质先减少后增多,矿物的衍射强度先降低后升高;SEM图像表明随着电压的不断增大,生成的硅酸凝胶逐渐增多,包覆土体颗粒,填充颗粒之间的孔隙,使得骨架颗粒连接紧密,从而使得土体强度增大;BET表面积孔隙分析表明,随着通电电压的升高和通电时间的延长,黄土的小孔隙增多,孔隙体积和表面积增大,孔径分布减小,平均孔径变化不大。

A Mechanism Study of Loess Reinforcing by Electricity-modified Sodium Silicate

In this paper, the reinforcing of loess by electricity-modified sodium silicate was studied through the orthogonal test and single factor control experiment. From the aspects of chemical composition, mineral composition and microstructure perspectives, the paper further analyzed and discussed the mechanism of loess reinforced by electricity-modified sodium silicate. The experimental results indicated that the unconfined compressive strength of the reinforced loess was proportional to the voltage and electrifying time; as the content of Na₂O and modulus kept increasing, the strength of the reinforced loess firstly decreased, then reached the lowest extreme point before it increased; amorphous phase peak groups appeared in the X-ray diffraction pattern, and as the Na₂O content kept increasing, the amorphous phase and the diffraction intensity experienced a fall before a rise; the SEM images suggested that the voltage of sodium silicate can accelerate the generation of silica, which would tighten the particle skeleton and improved the soil strength by covering the soil particles and filling the gaps between particles; the accelerated surface area-porosimetry system (BET) showed that with the increase of the voltage and the electrifying time, the small pores, pore volume and pore surface area were augmented while the scale of pore size was narrowed, and the average pore size remained hardly changed.