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Geoenvironmental performance of nanogeopolymer-modified natural soil: Towards sustainable geocomposite liner application

Year: 2024
Type: article
Abstract: Most clays are not suitable for compacted clay liner (CCL) use. To improve these substandard clay materials against heavy metals contamination and leachate permeation into the substrate soil. A moderate alkali solution of sodium silicate/sodium hydroxide (alkaline activator ratio: 0.5) concentration of 10 M and nanosized slag was used to build a nano-geopolymer (NGP). The synthesizes of NP was achieved through the blending of alkali solution with varying percentages of nano slag (5%, 10%, 15%, and 20%). The developed NGP was used to modify the CCLs, followed by experimental testing. The fabricated CCL specimens were subjected to a series of pH tests, cation exchange capacity tests (CEC.), compaction tests, swelling pressure tests, unconfined compressive strength (UCS) tests, hydraulic conductivity (HC) tests, and desiccation crack tests through a digital image analyzer to evaluate the geotechnical performance of the NGP treated CCL. The results revealed an average of 83% increase in strength. Meanwhile, the surface crack area ratio decreased to 28% upon 20% inclusion of NGP content. Conversely, swelling pressure (550 kPa - 130 kPa) and HC [[EQUATION]] to [[EQUATION]] decreased, indicating enhanced clay liner with high retention capacity as the percentages of NGP increased. Also, at 20% of nano-geopolymer content, the developed composite liner matched the acceptable standards for liner construction (hydraulic conductivity <10-9 m/s and UCS (0.9 MPa >0.2 MPa). Including NGP in CCL significantly improved the geotechnical properties of natural in-situ soil, making the investigated natural soil a suitable baseliner for leachate retention in landfills.
DOI: 10.1016/j.rineng.2024.103156
Language: English
Open Access status: gold
Estimated APC paid: $1,490
OpenAlex ID: W4403566613
FWCI: 2.353
Cites: 68
Cited by: 9
Related to: 10