Skip to main content
SpringerLink
Log in

Effect of sand grain size and boundary condition on the swelling behavior of bentonite–sand mixtures

  • Research Paper
  • Published:
Acta Geotechnica Aims and scope Submit manuscript

Abstract

Deep geological repository is a favorable choice for the long-term disposal of nuclear wastes. Bentonite–sand mixtures have been proposed as the potential engineered barrier materials because of their suitable swelling properties and good ability to seal under hydrated repository conditions. To investigate the effects of sand grain size on the engineering performance of bentonite–sand mixtures, we prepare five types of bentonite–sand mixtures by mixing bentonite with sand of varying particle size ranges (0.075–0.25 mm, 0.25–0.5 mm, 0.5–1 mm, 1–2 mm and 2–5 mm, respectively). We carry out sequential oedometer tests under different simulated repository conditions, including constant vertical stress (CVS), constant stiffness (CS) and constant volume (CV) conditions. The microstructural heterogeneity and anisotropy of these soil mixtures are characterized through the quantitative analysis of micro-CT scanning results. Experimental results reveal that both sand grain size and boundary condition significantly influence the swelling of soil mixtures. Under three conditions, the temporal evolutions of swelling stress and strain follow similar trends that they increase faster at the beginning and gradually stabilize afterward. Comparing the ultimate values, swelling strains follow CVS > CS > CV, while swelling stresses follow CV > CS > CVS. Under CS boundary conditions, as the stiffness coefficient increases, the swelling pressure increases and the swelling strain decreases. CT results further indicate that mixtures with larger sand inclusions are more structurally heterogeneous and anisotropic, resulting in increased inter-particle friction and collision and a higher energy dissipation during the swelling process. Moreover, the non-uniform distribution of bentonite in local zones would be intensified, which plays an important role in compromising swelling behavior. Therefore, soil samples mixed with larger sand particles present a smaller swelling stress and strain values. This study may guide the choice of engineered barrier materials toward an improved design and assessment of geological repository facilities.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13

Similar content being viewed by others

Data availability

Datasets related to this article can be found at http://dx.doi.org/10.17632/5bnkjdbppc.2.

References

  1. Agus SS, Arifin YF, Tripathy S, Schanz T (2013) Swelling pressure–suction relationship of heavily compacted bentonite–sand mixtures. Acta Geotech 8(2):155–165

    Article  Google Scholar 

  2. Amadi AA (2013) Swelling characteristics of compacted lateritic soil–bentonite mixtures subjected to municipal waste leachate contamination. Environ Earth Sci 70(6):2437–2442

    Article  Google Scholar 

  3. Bian X, Cui YJ, Zeng LL, Li XZ (2019) Swelling behavior of compacted bentonite with the presence of rock fracture. Eng Geol 254:25–33

    Article  Google Scholar 

  4. Chen YG, Liu LN, Ye WM, Cui YJ, Wu DB (2019) Deterioration of swelling pressure of compacted Gaomiaozi bentonite induced by heat combined with hyperalkaline conditions. Soils Found. https://doi.org/10.1016/j.sandf.2019.12.008

    Article  Google Scholar 

  5. Chen ZG, Tang CS, Zhu C, Shi B, Liu YM (2017) Compression, swelling and rebound behavior of GMZ bentonite/additive mixture under coupled hydro-mechanical condition. Eng Geol 221:50–60

    Article  Google Scholar 

  6. Cui SL (2012) Swelling characteristics of compacted bentonite–sand mixtures as buffer-backfill materials for HLW disposal. Doctor degree thesis. (in Chinese)

  7. Cui SL, Zhang HY, Zhang M (2012) Swelling characteristics of compacted GMZ bentonite–sand mixtures as a buffer/backfill material in China. Eng Geol 141–142(3):65–73

    Article  MathSciNet  Google Scholar 

  8. Darde B, Roux JN, Pereira JM, Dangla P, Talandier J, Vu MN, Tang AM (2020) Investigating the hydromechanical behaviour of bentonite pellets by swelling pressure tests and discrete element modelling. Acta Geotech 27:1–18

    Google Scholar 

  9. Delage P, Howat MD, Cui YJ (1998) The relationship between suction and swelling properties in a heavily compacted unsaturated clay. Eng Geol 50(1–2):31–48

    Article  Google Scholar 

  10. Delage P, Marcial D, Cui YJ, Ruiz X (2006) Ageing effects in a compacted bentonite: a microstructure approach. Géotechnique 56(5):291–304

    Article  Google Scholar 

  11. Dixon DA, Gray MN, Thomas AW (1985) A study of the compaction properties of potential clay-sand buffer mixtures for use in nuclear fuel waste disposal. Eng Geol 21(3–4):247–255

    Article  Google Scholar 

  12. Guerra AM, Cui YJ, He Y, Delage P, Mokni N, Tang AM, Aimedieu P, Bornert M, Bernier F (2018) Characterization of water retention, compressibility and swelling properties of a pellet/powder bentonite mixture. Eng Geol 248:14–21

    Article  Google Scholar 

  13. Guerra AM, Mokni N, Cui YJ, Delage P, Tang AM, Aimedieu P, Bernier F, Bornert M (2019) Impact of initial structural heterogeneity on long term swelling behavior of MX80 bentonite pellet/powder mixtures. Can Geotech J 57:1404–1416

    Article  Google Scholar 

  14. Japan Nuclear Cycle Development Institute (JNC) (2000) H12: project to establish the scientific and technical basis for HLW disposal in Japan, project overview report

  15. Jia LY, Chen YG, Ye WM, Cui YJ (2019) Effects of a simulated gap on anisotropic swelling pressure of compacted GMZ bentonite. Eng Geol 248:155–163

    Article  Google Scholar 

  16. Kenney TC, Veen WAV, Swallow MA, Sungaila MA (1992) Hydraulic conductivity of compacted bentonite–sand mixtures. Can Geotech J 29(3):364–374

    Article  Google Scholar 

  17. Komine H, Ogata N (1999) Experimental study on swelling characteristics of sand–bentonite mixture for nuclear waste disposal. Soils Found 39(2):83–97

    Article  Google Scholar 

  18. Komine HK, Yasuhara KY, Murakami SM (2015) Swelling characteristics of bentonites in artificial seawater. Can Geotech J 46(46):177–189

    Google Scholar 

  19. Lee JO, Choi H, Lee JY (2016) Thermal conductivity of compacted bentonite as a buffer material for a high-level radioactive waste repository. Ann Nucl Energy 94:848–855

    Article  Google Scholar 

  20. Liu ZR, Cui YJ, Ye WM, Chen B, Wang Q, Chen YG (2020) Investigation of the hydro-mechanical behaviour of GMZ bentonite pellet mixtures. Acta Geotech 4:2865–2875

    Article  Google Scholar 

  21. Liu YM, Wen ZJ (2003) An investigation of the physical properties of clayey materials used in nuclear waste disposal at great depth. Miner Rocks 23:42–45

    MathSciNet  Google Scholar 

  22. Lloret A, Villar MV (2007) Advances on the knowledge of the thermo-hydro-mechanical behavior of heavily compacted FEBEX bentonite. Phys Chem Earth 32(8–14):701–715

    Article  Google Scholar 

  23. Mollins LH, Stewart DI, Cousens TW (1996) Predicting the properties of bentonite–sand mixtures. Clay Miner 31(2):243–252

    Article  Google Scholar 

  24. Niu WJ, Ye WM, Song X (2019) Unsaturated permeability of Gaomiaozi bentonite under partially free-swelling conditions. Acta Geotech 15:1–30

    Google Scholar 

  25. Powell JS, Siemens GA, Take WA, Remenda VH (2013) Characterizing the swelling potential of Bearpaw clayshale. Eng Geol 158:89–97

    Article  Google Scholar 

  26. Prakasha KS, Chandrasekaran VS (2005) Behavior of marine sand-clay mixtures under static and cyclic triaxial shear. J Geotech Geoenviron 131(2):213–222

    Article  Google Scholar 

  27. Pusch R (1982) Mineral-water interactions and their influence on the physical behavior of highly compacted Na bentonite. Can Geotech J 19(3):381e7

    Article  Google Scholar 

  28. Pusch R (1979) Highly compacted sodium bentonite for isolating rock-deposited radioactive waste products. Nucl Technol U S A 45(2):153–157

    Google Scholar 

  29. Rawat A, Baille W, Tripathy S (2019) Swelling behavior of compacted bentonite–sand mixture during water infiltration. Eng Geol 257:105141

    Article  Google Scholar 

  30. Rice EE, Edgecombe DS, Compton PR, Best RE (1982) U.S. program assessing nuclear waste disposal in space—a 1981 status report. In: Space Mankind’s fourth environment, pp 295–305, Pergamon

  31. Saba S, Barnichon JD, Cui YJ, Tang AM, Delage P (2014) Microstructure and anisotropic swelling behaviour of compacted bentonite/sand mixture. J Rock Mech Geotech Eng 6(2):126–132

    Article  Google Scholar 

  32. Schanz T, Al-Badran Y (2014) Swelling pressure characteristics of compacted Chinese Gaomiaozi bentonite GMZ01. Soils Found 54(4):748–759

    Article  Google Scholar 

  33. Sharma B, Deka P (2019) A study on compressibility, swelling and permeability behaviour of bentonite–sand mixture. Geotech Charact Geoenviron Eng 100:43–50

    Google Scholar 

  34. Siemens G, Blatz JA (2009) Evaluation of the Influence of boundary confinement on the behavior of unsaturated swelling clay soils. Can Geotech J 46(3):339–356

    Article  Google Scholar 

  35. Sobti J, Singh SK (2019) A critical evaluation of the suction and swelling characteristics of sand–bentonite–coal ash mixes. Geotech Geol Eng 37:4229–4249

    Article  Google Scholar 

  36. Sun Z, Chen YG, Cui YJ, Xu HD, Ye WM, Wu DB (2018) Effect of synthetic water and cement solutions on the swelling pressure of compacted Gaomiaozi (GMZ) bentonite: the Beishan site case, Gansu, China. Eng Geol 244:66–74

    Article  Google Scholar 

  37. Sun DA, Sun WJ, Cui HB (2009) Swelling of compacted sand–bentonite mixtures. Appl Clay Sci 43(3):485–492

    Article  MathSciNet  Google Scholar 

  38. Sun WJ, Wei ZF, Sun DA, Liu SQ, Fatahi B, Wang XQ (2015) Evaluation of the swelling characteristics of bentonite–sand mixtures. Eng Geol 199:1–11

    Article  Google Scholar 

  39. Sun DA, Zhang J, Zhang J, Zhang L (2013) Swelling characteristics of GMZ bentonite and its mixtures with sand. Appl Clay Sci 83:224–230

    Article  Google Scholar 

  40. Swedish Nuclear Fuel and Waste Management (1992) Final disposal of spent nuclear fuel-SKB9, importance of the bedrock for safety, KBS technical report, p 20

  41. Tang AM, Cui YJ, Barnel N (2008) Thermo-mechanical behavior of a compacted swelling clay. Géotechnique 58(1):45–54

    Article  Google Scholar 

  42. Tang CS, Li SJ, Wang DW, Chen ZG, Shi B, Inyang H (2019) Experimental simulation of boundary condition effects on bentonite swelling in HLW repositories. Environ Earth Sci 78:135

    Article  Google Scholar 

  43. Tang CS, Tang AM, Cui YJ, Delage P, Schroeder C, Laure ED (2011) Investigating the swelling pressure of compacted crushed-Callovo-Oxfordian claystone. Phys Chem Earth 36(17–18):1857–1866

    Article  Google Scholar 

  44. Tay YY, Stewart DI, Cousens TW (2001) Shrinkage and desiccation cracking in bentonite–sand landfill liners. Eng Geol 60(1):263–274

    Article  Google Scholar 

  45. Tovey NK (1980) A digital computer technique for orientation analysis of micrographs of soil fabric. J Microsc 120:303–315

    Article  Google Scholar 

  46. Villar MV, Garciá-Siñeriz JL, Barcena I, Lloret A (2005) State of the bentonite barrier after five years operation of an in situ test simulating a high level radioactive waste repository. Eng Geol 80(3–4):175–198

    Article  Google Scholar 

  47. Villar MV, Iglesias RJ, Gutiérrez-Álvarez C, Carbonell B (2018) Hydraulic and mechanical properties of compacted bentonite after 18 years in barrier conditions. Appl Clay Sci 160:49–57

    Article  Google Scholar 

  48. Villar MV, Lloret A (2008) Influence of dry density and water content on the swelling of a compacted bentonite. Appl Clay Sci 39(1–2):38–49

    Article  Google Scholar 

  49. Villar MV, Pérez del Villar L, Martin PL, Pelayo M, Femández AM, Garralón A, Cuevas J, Leguey S, Caballero E, Huertas FJ, Jiménez de Cisneros C, Linares J, Reyes E, Delgado A, Fernández-Soler JM, Astudillo J (2006) The study of Spanish clays for their use as sealing materials in nuclear waste repositories: 20 years of progress. J Iber Geol 32(1):15–36

    Google Scholar 

  50. Walton S (1980) Nuclear waste disposal: U.S. Eyes Burial at Sea. Bioscience 30(11):729–732

    Article  Google Scholar 

  51. Wang J, Chen WM, Guo YH (2006) Deep geological disposal of high-level radioactive wastes in China. Chin J Rock Mech Eng 25(4):649–649 ((in Chinese))

    Google Scholar 

  52. Wang Q, Tang AM, Cui YJ, Delage P, Gatmiri B (2012) Experimental study on the swelling behavior of bentonite/claystone mixture. Eng Geol 124(1):59–66

    Article  Google Scholar 

  53. Wen ZJ (2006) Physical property of China’s buffer material for high-level radioactive waste repositories. Chin J Rock Mech Eng 25(4):794–800 ((in Chinese))

    Google Scholar 

  54. Ye WM, Chen YG, Chen B, Wang Q, Wang J (2010) Advances on the knowledge of the buffer/backfill properties of heavily-compacted GMZ bentonite. Eng Geol J 116:12–20

    Article  Google Scholar 

  55. Ye WM, Cui YJ, Qian LX, Chen B (2009) An experimental study of the water transfer through confined compacted GMZ bentonite. Eng Geol 108(3–4):169–176

    Article  Google Scholar 

  56. Ye WM, Qian LX, Chen B, Yu C (2009) Characteristics of micro-structure of densely compacted Gaomiaozi bentonite. J Tongji Univ 37(1):31–35 ((in Chinese))

    Google Scholar 

  57. Ye WM, Zheng ZJ, Chen B, Chen YG, Cui YJ, Wang J (2014) Effects of pH and temperature on the swelling pressure and hydraulic conductivity of compacted GMZ01 bentonite. Appl Clay Sci 101:192–198

    Article  Google Scholar 

  58. Ye WM, Zhu CM, Chen YG, Chen B, Cui YJ, Wang J (2015) Influence of salt solutions on the swelling behavior of the compacted GMZ01 bentonite. Environ Earth Sci 74(1):793–802

    Article  Google Scholar 

  59. Zeng Z, Cui YJ, Zhang F, Conil N, Talandier J (2019) Investigation of swelling pressure of bentonite/claystone mixture in the full range of bentonite fraction. Appl Clay Sci 178:105137.1-105137.7

    Article  Google Scholar 

  60. Zhang F, Ye WM, Chen YG, Chen B, Cui YJ (2016) Influences of salt solution concentration and vertical stress during saturation on the volume change behavior of compacted GMZ01 bentonite. Eng Geol 207:48–55

    Article  Google Scholar 

  61. Zhang Z, Ye WM, Liu ZR (2019) Investigation of swelling behaviors of GMZ bentonite pellet mixtures. In: 7th Asia-Pacific conference on unsaturated soils. https://doi.org/10.3208/jgssp.v07.037

  62. Zhang F, Ye WM, Wang Q, Chen YG, Chen B (2019) Effective stress incorporating osmotic suction and volume change behavior of compacted GMZ01 bentonite. Acta Geotech 15:1–10

    Google Scholar 

  63. Zhang F, Ye WM, Wang Q, Chen YG, Chen B (2019) An insight into the swelling pressure of GMZ01 bentonite with consideration of salt solution effects. Eng Geol 251:190–196

    Article  Google Scholar 

Download references

Acknowledgements

This work was supported by the National Key Research and Development Program of China (2020YFC1808101), National Natural Science Foundation of China (Grant No. 41772280, 41925012, 41902271, 42007244) and the Fundamental Research Funds for the Central Universities. The micro-CT tests in this study were conducted at State Key Laboratory of Paleobiology and Stratigraphy of Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences.

Author information

Authors and Affiliations

  1. School of Earth Sciences and Engineering, Nanjing University, 163 Xianlin Avenue, Nanjing, 210023, China

    Dong-Wei Wang, Chao-Sheng Tang, Sheng-Jie Li, Qing Cheng, Xiao-Hua Pan & Bin Shi

  2. Department of Civil and Environmental Engineering, Rowan University, 201 Mullica Hill Road, Glassboro, NJ, 08028, USA

    Cheng Zhu

Authors
  1. Dong-Wei Wang
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Cheng Zhu
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Chao-Sheng Tang
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Sheng-Jie Li
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Qing Cheng
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Xiao-Hua Pan
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Bin Shi
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Chao-Sheng Tang.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Wang, DW., Zhu, C., Tang, CS. et al. Effect of sand grain size and boundary condition on the swelling behavior of bentonite–sand mixtures. Acta Geotech. 16, 2759–2773 (2021). https://doi.org/10.1007/s11440-021-01194-w

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11440-021-01194-w

Keywords

Search

Navigation