不同分散剂对红黏土粒度分布的影响

红黏土由于土中游离氧化铁的存在，具有特殊的团粒结构。对于用密度计法进行红黏土的颗粒分析试验，各类规范中均建议加入分散剂。为更好评估土样分散的效果，运用分形理论，用分维值这一参数来描述土颗粒粒度特征。利用江西某地的红黏土，分别进行加入不同种类分散剂后的颗粒分析试验。结果表明,试样中加入六偏磷酸钠溶液作为分散剂后，得到的分维值较大，土颗粒集合体更分散。可见不同分散剂对于试验用红黏土的分散效果相差较大，加入适宜的分散剂才能更好地得到红黏土的实际粒度分布情况。试验结论对进一步认识和掌握红黏土的工程性质具有一定意义。

Effect of Different Dispersants on Grain Size Distribution of Red Clay

Red clay has a special aggregate structure due to the existence of free iron oxide in the soil. It is recommended to add dispersants in various specifications for particle analysis of red clay by densitometry. In order to better evaluate the dispersion effect of soil samples, fractal theory is used to describe the particle size characteristics of soil particles with fractal dimension. The results show that the fractal dimension value is larger and the soil particle aggregate is more dispersed when sodium hexametaphosphate solution is used as dispersant. It can be seen that the dispersion effects of different dispersants on the red clay used in the experiment are quite different, and the actual particle size distribution of red clay can be better obtained by adding appropriate dispersants. The experimental results are of great meaning for further understanding and mastering the engineering properties of red clay.