Effect of dispersion on grain size analysis in laser particle size method
ZHU Jie;BIE Xueqing;SUN Hao;XU Guizhong;School of Architecture and Civil Engineering,Jiangsu University of Science and Technology;Institute of Jiangsu Engineering and Research;Institute of Civil Engineering and Construction,Anhui University of Science and Technology;Geotechnical Research Institute,Yancheng Institute of Technology;
Soil particle size distribution,which can be analyzed by using laser particle size instrument,is an important factor influencing the soil engineering properties. In this paper,laser particle size instrument is used to analyze the natural clay and clay minerals particles' size distribution when they are under different dispersion such as non-dispersion,chemical dispersion,ultrasonic dispersion,etc. The experiment shows that when sample liquid limit is above 40 %,dispersion has to be chemical or ultrasonic,and no particular requirement is needed if it is less than 40 % for there is no much difference in final findings. However,no matter what the liquid limit is,the experimental performance is better when chemical or ultrasonic dispersion is applied. According to the experiment,mineral component and particle size are factors which will result in different size distribution curves when using different dispersion methods. It has been found that size distribution curves of montmorillonite are different for different dispersion methods and there is almost no change on Kaolin. In addition,if the particle size is smaller than 0. 02 mm,different distribution curves will be obtained with different dispersion methods.