保压时间对压实膨润土孔隙结构影响的试验研究

为研究膨润土压实成型时保压时间对其孔隙结构的影响,采用冻干法对试样进行干燥,然后使用压汞仪测试其孔隙结构特征。试验结果表明:孔隙比和集合体间孔隙体积随着保压时间的增加而减小,极小孔隙的体积则随着保压时间的增加而增大。与不保压样品相比,保压60 min高干密度和低干密度样品的孔隙比分别减少了4.53%、9.40%,集合体间孔径峰值则分别降低了17.03%、21.67%。研究结果可为膨润土压实成型参数及工程实践提供依据。

Experimental study on pressure maintaining time on pore structure of compacted bentonite

In order to investigate the effect of pressure maintaining time on pore structures of compacted bentonite,the samples were freezing dried and their pore structures were measured using a mercury intrusion porosimeter.The experimental results showed that,with increasing pressure maintaining time,the porosity ratio and pore volume of inter-aggregates decreased while the tiny pore volumes increased.Compared to the sample with no pressure maintaining,the porosity ratio of the sample with 60 minutes of pressure time was reduced by 4.53％,9.40％,and its peak value of inter-aggregate pore diameter was reduced by 17.03％,21.67％.These results can provide references for the engineering application of bentonite compaction.