Effect of mixing method on soil water retention and shrinkage properties of polymer-amended bentonite
Effect of mixing method on soil water retention and shrinkage properties of polymer-amended bentonite
Polymers have been shown to be able to enhance the resistance of clays to desiccation cracking. This is an important capability in engineering applications such as waste barriers. However, little is known about the reasons for this improvement (e.g., higher water retention, less shrinkage, lower hydraulic conductivity, higher tensile strength) and the most important variables affecting it, in particular the effects of different mixing methods. While dry mixing is easier to implement onsite, wet mixing produces better intercalation between clay and polymer and the two methods will yield different stabilizing outcomes. In this paper, the effects of two mixing methods on water retention and shrinkage properties are investigated. An anionic polymer of sodium carboxymethyl cellulose (Na-CMC) is added to Na-bentonite by dry and wet mixing. A series of laboratory experiments are conducted on amended and unamended bentonite to determine a) soil water retention characteristic (SWCC) using filter paper and dewpoint methods and b) shrinkage potential using the linear shrinkage test. Findings from this study will contribute to a better understanding of the mechanisms underlying the stabilizing effects of polymers on swelling clay and their sensitivity to mixing method.
S. Taheri; A. El-Zein
9th International Congress on Environmental Geotechnics (ICEG2023)
Engineered Barriers
https://doi.org/10.53243/ICEG2023-404
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