Projects per year
Abstract
In near-surface applications, hydraulic barriers are exposed to natural climatic variations, in the form of cycles of drying and wetting, which can result in cracking of the barrier material and a subsequent increase in the hydraulic conductivity. Ultimately, this reduces their ability to perform their end function. The aims of this paper are to study the mechanism of crack formation in colloidal silica grout barriers when exposed to severe drying and wetting cycles and to determine the effect on its hydraulic properties. To achieve these aims, grouted soil samples were created and exposed to severe drying and re-wetting. Samples were tested for hydraulic conductivity at each stage and 3D images of the pore structure were obtained from micro X-ray CT scanning. On drying, nanoscale cracks form within the CS matrix, which are 10s of nanometres in width, these have an associated air- entry value of ~20,000 kPa. Additional meso-scale cracks can also form in CS filled pores when surrounded by sand grains, due to conditions of restrained shrinkage. These cracks are typically hundreds of microns in width and have an associated air-entry value of ~200 kPa. X-ray CT analysis of the connectivity of this meso-scale pore space, filled by air after drying, indicates that although cracks form, a connected network does not, thus explaining the observation that even after severe drying the CS grouted sand retains a very low hydraulic conductivity.
Original language | English |
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Article number | 105579 |
Journal | Engineering Geology |
Volume | 270 |
Early online date | 6 Mar 2020 |
DOIs | |
Publication status | Published - 5 Jun 2020 |
Keywords
- hydraulic barrier
- water retention curve
- hydraulic conductivity
- x-ray tomography
- drying
- colloidal silica grouting
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Dive into the research topics of 'Desiccation behaviour of colloidal silica grouted sand: a new material for the creation of near surface hydraulic barriers'. Together they form a unique fingerprint.Profiles
Projects
- 1 Finished
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Decommissioning, Immobilisation and Storage soluTIons for NuClear wasTe InVEntories (DISTINCTIVE)
Lunn, R. (Principal Investigator), El Mountassir, G. (Co-investigator), Hamilton, A. (Co-investigator), Lord, R. (Co-investigator), Saafi, M. (Co-investigator), Tarantino, A. (Co-investigator) & Yang, S. (Co-investigator)
EPSRC (Engineering and Physical Sciences Research Council)
1/02/14 → 9/02/19
Project: Research
Datasets
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Data for: "Desiccation behaviour of colloidal silica grouted sand: A new material for the creation and report of near surface hydraulic barriers"
Pedrotti, M. (Creator), Wong, C. (Creator), El Mountassir, G. (Creator), Renshaw, J. (Creator) & Lunn, R. (Creator), University of Strathclyde, 24 Oct 2019
DOI: 10.15129/06540872-c30f-45c8-93fc-a2bfd524e944
Dataset
Activities
- 1 Invited talk
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Colloidal silica nanoparticle-hydrogel as grouting material for hydraulic barrier and soil stabilization: TEM and X-CT analysis on desiccation behaviour
Pedrotti, M. (Invited speaker)
26 Jun 2019Activity: Talk or Presentation › Invited talk