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An experimental investigation of nanoparticles assimilated hydro-mechanical behaviour of bentonite sand buffer

University of British Columbia

Disposal of high toxic radioactive waste is one of the alarming concerns of these days. Until now, the best accepted disposal method of such hazardous materials is placing into an underground containment system known as deep geological repository (DGR). DGR systems have risk of contaminating underground geosphere. Water may intrude into the DGR and intrusion mainly takes place as a form of advection. At present, the multiple barrier system is proposed around the hazardous waste containing cylinders known as clay barrier system. Bentonite sand buffer (BSB) is one of the main components of the multiple clay barrier system. Literature indicates extensive studies have been carried out with the existing BSB material. These researches emphasize to improve the hydraulic and mechanical behaviour of the BSB. To achieve the improved hydraulic and mechanical behaviour, it was intended to conduct laboratory test based study on the material, with integrated bentonite nanoparticles in saturated condition. Nanoparticles of bentonite were prepared using the ball milling process. Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (XEDS) and X-Ray Diffraction (XRD) analysis were adopted to characterize the size, elements and crystal structures of bentonite nanoparticles. Several laboratory tests such as the atterberg limit test, compaction test, unconfined compression test and one-dimensional consolidation test were conducted to examine the mechanical and hydraulic behaviour of the BSB, with varying proportion of nanoparticles. This is a new concept to capture the performance of BSB material after introducing nanoparticles. Fewer literatures directly relate to the problem and provide less evidence towards the achieved laboratory data. Furthermore, the obtained laboratory results illustrate significant improvement in the hydro-mechanical behaviour of the BSB material.

Text

2014-08-26

Attribution-NoDerivs 2.5 Canada

http://hdl.handle.net/2429/50183

Civil Engineering

University of British Columbia

UBCO

http://creativecommons.org/licenses/by-nd/2.5/ca/