Effects of temperature on swelling characteristics of GMZ bentonite
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摘要: 在25℃,40℃,60℃和90℃的蒸馏水中对高庙子（GMZ）膨润土进行了膨胀性能试验。由于在试验条件下渗透膨胀占主导地位,GMZ膨润土的膨胀性能随温度的升高而增大,其中最大膨胀率随温度线性增加,而膨胀力随温度呈指数增加。压实GMZ膨润土的膨胀性能可用em=KpD-3表示。N2吸附试验结果表明温度对GMZ膨润土的表面分维D基本没有影响。在渗透膨胀条件下,采用扩散双层模型计算发现膨胀系数K与温度Tc之间存在线性关系,并且通过GMZ膨润土和Bikaner膨润土的膨胀试验进行了验证。将K-Tc线性关系与em-p分形关系相结合,提出了温度作用下GMZ膨润土膨胀性能的一种简便定量评价方法。Abstract: The buffer/backfill performance of bentonite-based materials may be affected by the influences of temperature fields, thereby leading to uncertainties in the safe operation of repositories. In order to address this issue, the swelling tests on Gaomiaozi (GMZ) bentonite are carried out in distilled water at 25, 40, 60, and 90 °C. The results show that the swelling of GMZ bentonite increases with the temperature, owing to that the osmotic swelling dominates the swelling of compacted GMZ bentonite under the experimental conditions. The maximum swelling strain increases linearly with the temperature, whereas the swelling pressure increases exponentially with the temperature. The swelling characteristics of compacted GMZ bentonite can be expressed as em=KpD-3. According to the results of N2 adsorption tests, the fractal dimension, D, of GMZ bentonite is unaffected by the temperature. Calculated by the diffuse double layer model under osmotic swelling, a linear relation is found between the montmorillonite swelling coefficient K and the temperature Tc, which is verified by the swelling tests on GMZ bentonite and Bikaner bentonite. Combining the linear K−Tc relation and the fractal em-p relation, a simple method for evaluating the swelling of GMZ bentonite affected by the temperature is proposed.
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Keywords:
- bentonite /
- temperature /
- swelling property /
- fractal dimension /
- fractal method
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图 1 温度作用下膨胀性能试验装置
Figure 1. Experimental apparatus for swelling tests under different temperatures
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图 3 不同荷载作用下GMZ膨润土的εmax-Tc关系
Figure 3. Relationship between εmax and Tc of GMZ bentonite under different stresses
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图 4 25℃和60℃时GMZ膨润土的εmax-ρd关系
Figure 4. Relationship between εmax and ρd for GMZ bentonite at 25℃ and 60℃
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图 5 不同温度下GMZ膨润土的ps-ρd关系
Figure 5. Relationship between ps and ρd for GMZ bentonite under different temperatures
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图 7 计算的GMZ膨润土K-Tc关系
Figure 7. Calculated relationship between K and Tc for GMZ bentonite
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图 8 不同温度下GMZ膨润土的蒙脱石孔隙比估算值
Figure 8. Estimation of montmorillonite void ratio of GMZ bentonite under different temperatures
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图 9 不同温度下GMZ膨润土的蒙脱石孔隙比估算值[13]
Figure 9. Estimation of void ratio for Bikaner bentonite under different temperatures
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图 10 不同温度下GMZ膨润土最大膨胀率的预测值
Figure 10. Prediction of maximum swelling strain of GMZ bentonite at different temperatures
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图 11 不同干密度不同温度时GMZ膨润土的膨胀力
Figure 11. Prediction of swelling pressure of GMZ bentonite with different densities under different temperatures
表 1 GMZ膨润土的物理化学指标[22]
Table 1 Physicochemical indices of GMZ bentonite
土粒相对质量密度 液限wL/% 塑限wP/% 塑性指数IP 蒙脱石含量Cm/% 阳离子交换量/(cmol·kg-1) 主要交换性阳离子/(cmol·kg-1) Na+ Ca2+ Mg2+ K+ 2.66 276 37 239 75 75.1 36.2 24.7 11.9 3.62 
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表 2 膨胀变形试验中试样的初始状态和试验条件
Table 2 Initial and experimental conditions of samples in swelling deformation tests
初始干密度/(g·cm-3) 初始含水率/% 温度/℃ 竖向荷载/kPa 1.70 ± 0.03 17.7~18.1 25,40,60,90 6.25,12.5,25,50,100,200,400,800 1.50 ± 0.03 17.5~17.9 25,40,60,90 100,400 1.60 ± 0.03 17.6~18.2 25,40,60,90 100,400
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表 3 不同温度下膨胀系数K计算
Table 3 Calculated values of swelling coefficient K under different temperatures
Tc/℃ Z κ/m-1 u p/kPa K 25 19.172 691409134 3.456 1393.12 6.904 30 19.156 685683554 3.485 1465.08 6.992 40 19.123 674646562 3.542 1615.84 7.165 50 19.092 664125934 3.598 1775.94 7.336 60 19.061 654082622 3.652 1945.66 7.506 70 19.032 644481593 3.705 2125.26 7.673 80 19.003 635291309 3.756 2315.02 7.839 90 18.975 626483295 3.806 2515.22 8.003
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[1] KOMINE H, OGATA N. Experimental study on swelling characteristics of compacted bentonite[J]. Canadian Geotechnical Journal, 1994, 31(4): 478-490. doi: 10.1139/t94-057
[2] 刘樟荣, 崔玉军, 叶为民, 等. 缓冲/回填材料——膨润土颗粒及其混合物研究进展[J]. 岩土工程学报, 2020, 42(8): 1401-1410. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC202008007.htm LIU Zhang-rong, CUI Yu-jun, YE Wei-min, et al. Advances in researches on buffer/backfilling materials— bentonite pellets and pellet mixtures[J]. Chinese Journal of Geotechnical Engineering, 2020, 42(8): 1401-1410. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC202008007.htm
[3] 徐永福. 考虑渗透吸力影响膨润土的修正有效应力及其验证[J]. 岩土工程学报, 2019, 41(4): 631-638. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201904006.htm XU Yong-fu. Modified effective stress induced by osmotic suction and its validation in volume change and shear strength of bentonite in saline solutions[J]. Chinese Journal of Geotechnical Engineering, 2019, 41(4): 631-638. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201904006.htm
[4] CHO W J, LEE J O, KANG C H. Influence of temperature elevation on the sealing performance of a potential buffer material for a high-level radioactive waste repository[J]. Annals of Nuclear Energy, 2000, 27(14): 1271-1284. doi: 10.1016/S0306-4549(99)00124-3
[5] 李晓月, 徐永福. 盐溶液中膨润土峰值剪切强度的计算方法[J]. 岩土工程学报, 2019, 41(5): 885-891. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201905014.htm LI Xiao-yue, XU Yong-fu. Calculation of peak shear strength of bentonite in salt solutions[J]. Chinese Journal of Geotechnical Engineering, 2019, 41(5): 885-891. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201905014.htm
[6] 张虎元, 崔素丽, 刘吉胜, 等. 混合型缓冲回填材料膨胀力试验研究[J]. 岩土工程学报, 2010, 31(10): 3087-3095. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201010011.htm ZHANG Hu-yuan, CUI Su-li, LIU Jie-sheng, et al. Experimental study of swelling pressure of compacted bentonite-sand mixture[J]. Chinese Journal of Geotechnical Engineering, 2010, 31(10): 3087-3095. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201010011.htm
[7] SUN W J, ZONG FEI Y, SUN D A, et al. Swelling prediction of bentonite-sand mixtures in the full range of sand content[J]. Engineering Geology, 2017, 222: 146-155. doi: 10.1016/j.enggeo.2017.04.004
[8] LLORET MORANCHO A, VILLAR M V, SANCHEZ M, et al. Mechanical behaviour of heavily compacted bentonite under high suction changes[J]. Géotechnique, 2003, 53: 27-40. doi: 10.1680/geot.2003.53.1.27
[9] HERBERT H J, KASBOHM J, SPRENGER H, et al. Swelling pressures of MX-80 bentonite in solutions of different ionic strength[J]. Physics and Chemistry of the Earth, Parts A/B/C, 2008, 33: 327-342. doi: 10.1016/j.pce.2008.10.005
[10] 项国圣, 姜昊, 徐永福. 压实膨润土膨胀变形的分形计算方法[J]. 岩土力学, 2015, 36(4): 1009-1014. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201504015.htm XIANG Guo-sheng, JIANG Hao, XU Yong-fu. Fractal calculation method for swelling deformation of compacted bentonite[J]. Rock and Soil Mechanics, 2015, 36(4): 1009-1014. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201504015.htm
[11] PUSCH R. Swelling Pressure of Highly Compacted Bentonite[R]. Stockholm: Swedish Nuclear Fuel Supply Co, 1980.
[12] BAG R, RABBANI A. Effect of temperature on swelling pressure and compressibility characteristics of soil[J]. Applied Clay Science, 2017, 136: 1-7. doi: 10.1016/j.clay.2016.10.043
[13] CHEN Y G, DONG X X, ZHANG X D, et al. Combined thermal and saline effects on the swelling pressure of densely compacted GMZ bentonite[J]. Applied Clay Science, 2018, 166: 318-326. doi: 10.1016/j.clay.2018.10.001
[14] PUSCH R, KARNLAND O, HOKMARK H. GMM-Ea General Microstructural Model for Qualitative and Quantitative Studies of Smectite Clays[R]. Stockholm: Swedish Nuclear Fuel Supply Co, 1990.
[15] LIU L. Prediction of swelling pressures of different types of bentonite in dilute solutions[J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2013, 434: 303-318. doi: 10.1016/j.colsurfa.2013.05.068
[16] 陈永贵, 蒯琪, 叶为民, 等. 高压实膨润土膨胀力预测研究[J]. 同济大学学报, 2018, 46(12): 1628-1636. https://www.cnki.com.cn/Article/CJFDTOTAL-TJDZ201812003.htm CHEN Yong-gui, KUAI Qi, YE Wei-min, et al. Prediction of Swelling Pressure for Compacted Bentonite[J]. Journal of Tongji University, 2018, 46(12): 1628-1636. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-TJDZ201812003.htm
[17] YE W M, WAN M, CHEN B, et al. Temperature effects on the swelling pressure and saturated hydraulic conductivity of the compacted GMZ01 bentonite[J]. Environmental Earth Sciences, 2013, 68(1): 281-288.
[18] CUI S, DU Y, WANG X, et al. Influence of temperature on swelling deformation characteristic of compacted GMZ bentonite-sand mixtures[J]. Journal of Central South University, 2018, 25(11): 2819-2830.
[19] ROMERO E, VILLAR M V, LLORET A. Thermo- hydro-mechanical behaviour of two heavily overconsolidated clays[J]. Engineering Geology, 2005, 81(3): 255-268.
[20] TRIPATHY S, BAG R, THOMAS H R. Enhanced Isothermal Effect on Swelling Pressure of Compacted MX80 Bentonite[M]. Cham: Springer, 2015: 537-539.
[21] VILLAR M V, LLORET A. Influence of temperature on the hydro-mechanical behaviour of a compacted bentonite[J]. Applied Clay Science, 2004, 26(1/2/3/4): 337-350.
[22] XIANG G S, XU Y F, YU F, et al. Prediction of swelling characteristics of compacted GMZ bentonite in salt solution incorporating ion-exchange reactions[J]. Clays and Clay Minerals, 2019, 67(2): 163-172.
[23] TRIPATHY S, SRIDHARAN A, SCHANZ T. Swelling pressures of compacted bentonites from diffuse double layer theory[J]. Canadian Geotechnical Journal, 2004, 41(3): 437-450.
[24] XU Y F, MATSUOKA H, SUN D A. Swelling characteristics of fractal-textured bentonite and its mixtures[J]. Applied Clay Science, 2003, 22(4): 197-209.
[25] XU Y F, XIANG G S, JINAG H, et al. Role of osmotic suction in volume change of clays in salt solution[J]. Applied Clay Science, 2014, 101: 354-361.
[26] PASTINA B, HELLÄ P. Expected Evolution of a Spent Nuclear Fuel Repository at Olkiluoto[R]. Posiva Oy, 2006.
[27] CUI S L, ZHANG H Y, ZHANG M. Swelling characteristics of compacted GMZ bentonite-sand mixtures as a buffer/backfill material in China[J]. Engineering Geology, 2012, 141: 65-73.
[28] ZHANG F, YE W M, CHEN Y G, et al. Influences of salt solution concentration and vertical stress during saturation on the volume change behavior of compacted GMZ01 bentonite[J]. Engineering Geology, 2016, 207: 48-55.
[29] SUN D A, CUI H B, SUN W J. Swelling of compacted sand-bentonite mixtures[J]. Applied Clay Science, 2009, 43: 485-492.
[30] YIN Y. Adsorption isotherm on fractally porous materials[J]. Langmuir, 1991, 7(2): 216-218.
[31] KAHR G, KRAEHENBUEHL F, STOECKLI H F, et al. Study of the water-bentonite system by vapour adsorption, immersion calorimetry and X-ray techniques: II. Heats of immersion, swelling pressures and thermodynamic properties[J]. Clay Minerals, 1990, 25(4): 499-506.
[32] XIANG G S, YE W M, XU Y F, et al. Swelling deformation of Na-bentonite in solutions containing different cations[J]. Engineering Geology, 2020, 105757.
[33] XIANG G S, YE W M, YU F, et al. Surface fractal dimension of bentonite affected by long-term corrosion in alkaline solution[J]. Applied Clay Science, 2019, 175: 94-101.
[34] KOMINE H, OGATA N. New equations for swelling characteristics of bentonite-based buffer materials[J]. Canadian Geotechnical Journal, 2003, 40(2): 460-475.
[35] SUN D A, ZHANG, J Y, ZHANG J R, et al. Swelling characteristics of GMZ bentonite and its mixtures with sand[J]. Applied Clay Science, 2013, 83: 224-230.
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