Three-year performance of in-situ solidified/stabilised soil using novel MgO-bearing binders
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Jin, F., Wang, F., & Al-Tabbaa, A. (2015). Three-year performance of in-situ solidified/stabilised soil using novel MgO-bearing binders. Chemosphere, 144 681-688. https://doi.org/10.1016/j.chemosphere.2015.09.046
A new group of MgO-bearing binders has been developed recently which showed improved sustainability and technical performance compared to Portland cement (PC). However, the application of these MgO-bearing binders in the solidification/ stabilisation (S/S) techniques is very limited. This study investigates the three-year performance of a highly contaminated soil treated by in-situ S/S using MgO-bearing binders and PC. The core quality, strength, permeability and the leaching properties of the S/S materials were evaluated. The effects of binder composition, addition of inorgano-organo-clay (IOC) and the grout content on the properties of the 3-y S/S materials are discussed. It is found that although MgO alone provided negligible strength to the soil, it is superior in immobilising both inorganic and organic contaminants. Replacing MgO by ground granulated blast-furnace slag (GGBS) significantly enhanced the strength while also performed well in immobilising the contaminants. The improved pH buffering capacity was attributed to the low solubilities of brucite and hydrotalcite-like phases formed in the MgO-bearing binders, and was also the reason for the improved performance in stabilising contaminants. The addition of IOC slightly decreased the strength and the permeability of the S/S materials but inconsistent effect on the contaminant immobilisation was found depending on the binder composition. This study showed no degradation of the S/S materials after 3 y exposure to field conditions and has proved the applicability and the advantages of MgO-bearing binders over PC in S/S.
MgO, GGBS, in-situ stabilisation/solidification, strength, permeability, leaching
The authors are grateful to the funding from EPSRC (Grant No.: NMZJ/116 RG60240) to support this research. The samples were all retreived from a field trial sponsored by EPSRC/TSB (Grant No.: TP/5/CON/6/I/H0304E).
External DOI: https://doi.org/10.1016/j.chemosphere.2015.09.046
This record's URL: https://www.repository.cam.ac.uk/handle/1810/250591
Attribution 2.0 UK: England & Wales
Licence URL: http://creativecommons.org/licenses/by/2.0/uk/