高温作用对膨润土孔隙结构的影响

Influence of high temperature on the pore structure of bentonite

为研究高温作用以及热作用时间对压实膨润土孔隙结构的影响,以高庙子天然钠基膨润土为研究对象,试样经90℃、150℃和170℃分别热作用2个月、4个月和6个月后,采用冻干法进行干燥,然后使用压汞仪测试其孔隙结构特征。结果表明:集合体间的孔隙随着老化温度的增加有变大的趋势;集合体间孔隙体积随着老化时间的延长而减小,减小了6.47%～22.38%;集合体内孔隙的体积则随着老化时间的延长而增大,增大了6.47%～10.15%。热作用对膨润土孔隙结构的影响存在温度效应和时间效应,在地质处置中,应该充分考虑热作用对膨润土微观结构的影响。

In order to investigate the effect of high temperature and heating time on the pore structure of compacted bentonite,Gao Miaozi(GMZ)nature Na-bentonite was used as study object.Firstly,the samples were heated for 2,4 and 6 months at 90℃,150℃ and 170℃,respectively,then they were dried by freezing dry method.Finally,its pore structure was measured by mercury intrusion porosimetry.The results showed that the inter-aggregate pores were more large with increase of temperature,and inter-aggregate pore volume decreased with increase of heating time,and decreased by 6.47%~22.38%.The intra-aggregate pore volume increased with increase of heating time,and increased by 6.47%~10.15%.It had temperature and time effect for that Influence of high temperature effect on pore structure of bentonite.In geological disposal,it should be considered that influence of heat on pore structure of bentonite.