改性膨胀土微观孔隙定量研究

利用自动吸附仪对石灰、水泥改性膨胀土进行液氮吸附试验,并通过吸附理论对改性膨胀土内微观孔隙进行了定量研究。发现改性膨胀土中存在较多窄缝状孔隙;膨胀土改性前后其微孔体积以8.4A左右的孔隙为主;30A以上的中等孔隙离散分布;改性材料对膨胀土结构的影响主要是针对200A以上的孔隙;石灰与水泥的掺入使得膨胀土内的微孔体积减小,中孔以上孔隙体积增加。最后通过改性膨胀土的扫描电镜图象对吸附试验的结果进行了对比分析。

Quantitative research on micropores of modified expansive soils

Liquid N_2 adsorption test was made on lime and cement modified expansi ve soils by automatic adsorption apparatus, and quantitative analysis was made o n micro pores of modified expansive soils through adsorption theory. It was foun d that there exist many slit-like pores inside the modified expansive soils; mi cropo res of expansive soils before and after modification mainly concentrates around 8.4A; mesopores over 30A distribute divergingly; modification materials mainly affect pores over 200A; admixture of modification materials decreases micropore volume of expansive soils, while enhances mesopore volume. Finally, compared with resul ts of adsorption test the scanning electron images of expansive soils were analy zed.