| 项国圣,Nashiry Zubery Mwachulla,宋绍辉,卞云飞.NaOH 溶液侵蚀对膨润土力学性能的影响[J].甘肃地质,2025,34(3):68-73 |
| NaOH 溶液侵蚀对膨润土力学性能的影响 |
| MTHE IMPACT OF NaOH SOLUTION EROSION ON THE MECHANICAL PROPERTIES OF BENTONITE |
| |
| DOI： |
| 中文关键词: 膨润土 碱溶液 膨胀性能 抗剪强度 |
| 英文关键词:bentonite alkaline solution swelling shear strength |
| 基金项目:安徽省自然科学基金项目(2208085MD98，2108085QD168） |
|
| 摘要点击次数: 4 |
| 全文下载次数: 0 |
| 中文摘要: |
| 在高放射性废物处置库中，混凝土材料在长期使用后会逐渐衰退分解，形成的碱性孔隙水会对膨润土的屏障性能产生不利影响。 通过NaOH溶液模拟碱性条件，开展了膨润土的膨胀变形试验和直接剪切试验。 试验结果表明，随着NaOH溶液浓度的增加，碱溶液对蒙脱石有强烈的溶蚀作用，导致蒙脱石的含量降低，使得相同荷载作用下膨润土的膨胀率降低，孔隙比减小，颗粒与颗粒之间接触紧密。 通过XRD、SEM发现，随着NaOH溶液浓度的增加，碱溶液与蒙脱石之间的反应使得颗粒之间胶结作用增强，分散的蒙脱石片层逐渐向块状和板状转化，导致抗剪强度增强。由于膨润土自身的高膨胀性、低渗透性被选为处置库垫层最优的回填材料。然而处置库处于地下，可能因受污染物滤液或地下水溶液（例如盐溶液或碱溶液）的影响而导致膨润土垫层的密封性产生影响。因此本研究对高放射性废物处置库的安全具有指导意义。 |
| 英文摘要: |
| In the high -level radioactive waste disposal repository, the concrete materials will gradually deteriorate and decompose after long-term use, and the generated alkaline pore water will have adverse effects on the barrier performance of bentonite. The researchers in this paper conducted expansion deformation tests and direct shear tests on bentonite by simulating alkaline conditions with NaOH solution. The test results show that: With the increase of NaOH solution concentration, the alkaline solution has a strong dissolution effect on montmorillonite, resulting in a decrease in the content of montmorillonite, which leads to a decrease in the expansion rate of bentonite under the same load and a reduction in the void ratio, and closer particle contact. Through XRD and SEM analysis, it was found that with the increase of NaOH solution concentration, the reaction between the alkaline solution and montmorillonite strengthens the bonding effect between particles, and the dispersed montmorillonite lamellae gradually transform into block -like and plate -like shapes, resulting in an increase in shear strength. Due to the high expansion and low permeability of bentonite, it is selected as the optimal backfill material for the disposal repository cushion layer. However, the disposal repository is underground and may be affected by pollutant filtrate or groundwater solutions （such as salt solutions or alkaline solutions）,which may affect the sealing performance of the bentonite cushion layer. Therefore, this study has guiding significance for the safety of high-level radioactive waste disposal repositories. |
| 查看全文 查看/发表评论 下载PDF阅读器 |
| 关闭 |
|
|
|
