An insight into grain interaction in bentonite/claystone mixtures
Tóm tắt
This paper investigates the swelling mechanism of Callovo-Oxfordian (COx) claystone grain in its mixtures with bentonite which are potential candidate for engineered barriers in the French high-level radioactive waste disposal. The swelling pressures of MX80 bentonite/COx claystone mixtures with various bentonite fractions and dry densities were first experimentally determined by carrying out infiltration tests under constant-volume conditions. According to the experimental results, the claystone void ratio after hydration in the mixtures was estimated by taking into account the bentonite/claystone grain interaction. Then, the volume change of claystone grain under different pressures applied by swollen bentonite was determined. The volumetric strain of claystone grain was found to decrease linearly with the increase in pressure. This allowed the indirect determination of the swelling pressure of claystone grain. The determined value was found to be comparable to that estimated from the relationship between the void ratio and the swelling pressure in the direction perpendicular to the stratification of intact COx claystone, confirming the identified swelling mechanism of bentonite/claystone mixtures.
Tài liệu tham khảo
Andra (2005). Dossier 2005 Argile-synthesis: evaluation of the feasibility of a geological repository in an argillaceous formation (Meuse/Haute-Marne Site). French National Radioactive Waste Management Agency, Chatenay-Malabry CEDEX 241 pp. Accessed 22 November 2018
Middelhoff M, Cuisinier O, Masrouri F, Talandier J, Conil N (2020) Combined impact of selected material properties and environmental conditions on the swelling pressure of compacted claystone/bentonite mixtures. Appl Clay Sci 184:105389
Zeng ZX, 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. https://doi.org/10.1016/j.clay.2019.105137
Zhang CL, Kröhn KP (2019) Sealing behaviour of crushed claystone–bentonite mixtures. Geomech Energy Environ 17:90–105
Karnland O, Nilsson U, Weber H, Wersin P (2008) Sealing ability of Wyoming bentonite pellets foreseen as buffer material–laboratory results. Phys Chem Earth Parts A/B/C 33:S472–S475
Komine H, Ogata N (1994) Experimental study on swelling characteristics of compacted bentonite. Can Geotech J 31(4):478–490
Komine H, Ogata N (1999) Experimental study on swelling characteristics of sand-bentonite mixture for nuclear waste disposal. Soils Found 39(2):83–97
Sun DA, Cui H, Sun WJ (2009) Swelling of compacted sand-bentonite mixtures. Appl Clay Sci 43(3–4):485–492
Agus SS, Schanz T (2008) A method for predicting the swelling pressure of compacted bentonites. Acta Geotech 3(2):125
Wang Q, Tang AM, Cui YJ, Delage P, Gatmiri B (2012) Experimental study on the swelling behaviour of bentonite/claystone mixture. Eng Geol 124:59–66
Zeng ZX, Cui YJ, Conil N, Talandier J (2020) Effects of technological voids and hydration time on the hydro-mechanical behaviour of compacted bentonite/claystone mixture. Géotechnique. https://doi.org/10.1680/jgeot.19.P.220
Tang CS, Tang AM, Cui YJ, Delage P, Schroeder C, De Laure E (2011) Investigating the pressure of compacted crushed-Callovo-Oxfordian claystone. Phys Chem Earth Parts A/B/C 36(17–18):1857–1866
Zeng ZX, Cui YJ, Conil N, Talandier J (2020) Experimental investigation and modeling of the hydraulic conductivity of saturated bentonite-claystone mixture. Int J Geomech. https://doi.org/10.1061/(ASCE)GM.1943-5622.0001817
Yang LA, Tan TS, Tan SA, Leung CF (2002) One-dimensional self-weight consolidation of a lumpy clay fill. Géotechnique 52(10):713–725
Zhang F, Cui YJ, Conil N, Talandier J (2020) Assessment of swelling pressure determination methods with intact Callovo-Oxfordian claystone. Rock Mech Rock Eng 53(4):1879–1888
Zhang CL, Wieczorek K, Xie ML (2010) Swelling experiments on mudstones. J Rock Mech Geotech Eng 2(1):44–51
Mayne PW, Kulhawy FH (1982) Ko-OCR relationships in soil. J Soil Mech Found Div 108(6):851–872
Mohajerani M, Delage P, Monfared M, Tang AM, Sulem J, Gatmiri B (2011) Oedometric compression and swelling behaviour of the Callovo-Oxfordian argillite. Int J Rock Mech Min Sci 48(4):606–615
Zhang CL, Czaikowski O, Rothfuchs T (2010) Thermo-Hydro-Mechanical behaviour of the Callovo-Oxfordian clay rock. In: Final report