Mechanics compacted bentonite

In the Swedish KBS-project a mixture of bentonite and quartz (10 90) or compacted bentonite were proposed at an early stage as possible backfill materials. Bentonite is a rather common mont-morillonitic clay with good mechanical properties and chemical... 

Lloret, A., Villar, M.V., Sanchez, M., Gens, A., Pintado, X., and Alonso, E.E., Mechanical behavior of heavily compacted bentonite under high suction changes. Geotechnique, 53(1) 27-40. 2003. 

Villar, M.V., and Lloret, A., Temperature influence on mechanical behavior of a compacted bentonite. FToc. GEPROC. Int. Conf on Coupled THMC Processes in Geosystems, 2003. 

A buffer of compacted bentonite is planned to be used to prevent the movement of groundwater and the consequential escape of material from a geological repository for spent nuclear fuel. Fluid flow, phase changes, mechanical behaviour of the buffer, rock, and the waste canisters, and the heat produced by the waste constitute a coupled thermohydromechanical system. The aim of the study is to derive a general thermodynamically consistent THM model for an arbitrary mixture. The general theory is applied to the thermohydraulic modelling of a mixture of compacted bentonite, liquid water, vapour, and air. 

TEMPERATURE INFLUENCE ON THE MECHANICAL BEHAVIOUR OF A COMPACTED BENTONITE... 

Villar, M.V. Lloret, A. 2002. Temperature influence on the hydro-mechanical behaviour of a compacted bentonite. Proc. Int. Meeting Clays in Natural and Engineered Barriers for Radioactive Waste Confinement. ANDRA, Reims. 

Muurinen, A., Rantanen, J. Pentilla-Hiltunen, P. 1985. Diffusion mechanism of strontium, cesium and cobalt in compacted bentonite. Scientific Basis for Nuclear Waste Management, IX, 617-624. 

Three tests on bentonite compacted at an initial dry density of 1.7 g/cm with its hygroscopic water content have been performed at different temperatures (20, 40 and 60 °C), following the suction and stress paths indicated in Figure 4. In the first step, under a vertical load of 0.1 MPa, the suction of the sample was equalised to 14 MPa (due to mechanical limitations of the cell, this is the maximum suction that can be controlled). Afterwards, keeping this suction constant, the vertical load was increased up to 5 MPa. Under this vertical load, suction was decreased by steps until... 

Mixtures of naturally deposited sand, medium plasticity clay, and bentonite with recycled rubber produced composite materials suitable for use in ground improvement (Becker and Vrettos, 2011). Mechanical properties of soils relevant to the application of such composites in geotechnical engineering problems were investigated. The compaction, permeability, compressibility, and flexural and shear strength were determined for typical mixtures along swelling of the bentonite-mbber mixtures. 

Mase GE (1970) Theory and problems of continuum mechanics. McGraw-Hill, New York Milton GW (2002) The theory of composites. Cambridge University Press, Cambridge Mitchell JK (1993) Fundamentals of soil behavior, 2nd edn. Wiley, Hoboken Miyahara K, Ashida T, Kohara Y, Yusa Y, Sasaki N (1991) Effect of bulk density on diffusion for cesium in compacted sodium bentonite. Radiochimica Acta 52/53 293-297 Moore WJ (1972) Physical chemistry, 4th edn. Prentice-HaU, Englewood CUffs Nakano M (1991) Material transporting soils. University Tokyo Press, Tokyo (in Japanese)... 

Sato H, Ashida T, Kohara Y, Yui M, Sasaki N (1992) Effect of dry density on diffusion of some radionuchdes in compacted sodium bentonite. J Nucl Sd Tech 29(9) 873-882 Sato H, Shibutani T (1994) Study on adsorption and diffusion mechanism of nuclides in buffer material and geosphere. PNC Technical Report, 91, 71—88 (in Japanese)... 

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