中文摘要：

为研究锌离子对膨润土重塑土压缩特性的影响,对人工制备的受不同浓度Zn2＋污染的高含水率膨润土开展一维压缩、自由膨胀率、物理化学性质和扫描电镜试验。试验结果表明,在竖向压力低于某临界值（200 kPa）时,相同压力下随着Zn2＋浓度增大,膨润土的孔隙比和压缩指数均降低,但当Zn2＋浓度高于某临界值（0.02 mol/L）时,继续增加污染浓度膨润土的孔隙比基本保持不变,压缩指数略有降低。当竖向压力超过该临界值（200 kPa）后,膨润土的孔隙比基本不受孔隙液物理化学性质影响,仅由竖向压力决定。此外,随着孔隙液Zn2＋浓度增大,膨润土的孔隙液pH值和土样比表面积减小,颗粒直径增大,膨润土中蜂窝状结构遭到破坏,黏土矿物片逐渐团聚成大直径颗粒,小孔隙消失,生成一些大的团粒间孔隙。

英文摘要：

In order to study the influence of zinc ions on the compressibility of remolded bentonite, a series of tests including one-dimensional compression, free swelling ratio, physicochemical property, and scanning electron microscopy were performed on artificially prepared bentonite of high water content with different concentrations of zinc ions. Test results indicate that, when the vertical load is lower than a critical value of 200 kPa, the void ratio and compression index of the contaminated bentonite will decrease with the increasing concentration of zinc ions under a constant vertical load. However, if the concentration of zinc ions is greater than a threshold value of 0.02 mol/L, there will be little change in void ratio of bentonite; and the compression index will just decrease a little. As the vertical load is greater than 200 kPa, basically the void ratio of bentonite will not be influenced by the physicochemical property of the pore fluid but only be determined by vertical load. In addition, experimental analysis shows that as the concentration of the zinc ions increases, pH value of the pore fluid and specific surface area will be decreased; but the particle diameter will be increased. Furthermore, the dispersed structure of bentonite will be gradually destroyed; clay mineral flakes will form big aggregates; and large inter-aggregate voids will come into being due to the zinc contamination.