论文部分内容阅读
针对高庙子膨润土在不同含水率和不同干密度条件下的微观孔隙结构时效性进行了试验研究。首先采用静力压实法将3种不同含水率条件下的高庙子膨润土粉末压实到2种不同密实状态,压实结束后保持试样体积和含水率不变分别静置1,30,90 d,然后分别采用压汞仪法和扫描电镜法对静置不同时间后试样的微观孔隙结构进行量测。试验结果表明,高庙子膨润土集合体间大孔隙随静置时间增加逐渐减少,而集合体内孔隙和小于压汞仪最小探测粒径的极小孔隙逐渐增多;随着静置时间的延续,膨润土微观孔隙结构趋于均匀化。产生上述现象的主要原因是:试样静置过程中,为达到吸力平衡,试样各微观孔隙结构中水分子重分布,导致层叠体内水分子层数增多,蒙脱石水化;随着水化的进行,层叠体晶层间水分子层数逐渐增多,同时厚的层叠体逐渐裂开成薄的层叠体,导致集合体内小孔隙增多;在体积不变条件下,集合体间大孔隙不断被挤压填充,孔隙体积逐渐减少。
Aiming at the aging of microscopic pore structure of Gaomiaozi Bentonite under different moisture content and dry density, Firstly, the Gaomiaozi bentonite powder under three different water content conditions was compacted into two different densified states by static compaction method. After the compaction, the sample volume and water content were kept unchanged for 1, 30, After 90 d, the microscopic pore structure of the sample after standing for different time was measured by mercury intrusion porosimetry and scanning electron microscope respectively. The results showed that the macropores in the Gaomiaozi bentonite assemblage decreased gradually with the increasing of the standing time, while the smallest pores in the aggregates and the smallest detected diameter of the mercury porosimetry increased gradually. With the extension of the standing time, the bentonite Microscopic pore structure tends to be uniform. The main reasons for the above phenomenon are as follows: During the standing process of the sample, in order to achieve the balance of suction, the water molecules in each microscopic pore structure of the sample are redistributed, resulting in an increase in the number of water molecules in the laminate and the hydration of the montmorillonite; As a result, the number of water molecules between the crystal layers of the laminated body gradually increases, meanwhile, the thick laminated body gradually splits into a thin laminated body, resulting in the increase of small pores in the aggregate; under the condition of constant volume, the large pores in the aggregate Extruded and filled, pore volume gradually reduced.