膨润土微观结构SEM观察中的表观孔隙率

对膨润土微观结构SEM观察时出现的表观孔隙率与宏观孔隙率不一致的问题进行了分析,讨论了SEM观察时冻干法对饱和膨润土微观结构的影响,得到表观孔隙率与宏观孔隙率之间的关系式,证实了膨润土中存在粒间孔隙和粒内孔隙,且2种类型的孔隙可以通过SEM的试验方法区分开.随着干密度的变化,粒内孔隙的孔隙比保持不变,根据SEM分析得到的粒内孔隙比与已有结果很接近.表观孔隙率与宏观孔隙率不一致主要是由于SEM照片没有反映出膨润土的粒内孔隙造成的.

Apparent porosity in SEM observation of microstructure of bentonite

An analysis was performed on difference between the apparent porosity and macro porosity in SEM observation of bentonite microstructure.The influence of freeze-drying on the microstructure of saturated bentonite was discussed,and the relationship between the apparent porosity and macro porosity was obtained.It is verified that there are two kinds of pores in bentonite,i.e. the interparticle pores and intraparticle pores,and they can be identified by SEM observation.With the variation of dry density,the porosity of intraparticle pores keeps invariable,and the intraparticle void ratio obtained by SEM analysis is much close to that of A.Lloret.The difference between the apparent porosity and macro porosity is mainly caused by the fact that the intraparticle pores are not shown in SEM photos.