Performance of a needle punched geosynthetic clay liner in groundwater protection on roads in cold climate

Field observations of downslope bentonite erosion from a geosynthetic clay liner (GCL) covered by only a black geomembrane are reported for a composite liner left exposed without a protective soil cover for much longer than recommended by the GCL manufacturer. A new nondestructive, light-transmission technique developed to investigate bentonite erosion features in the field is presented. A classification system is developed to describe the type of erosion features observed. Results from five field investigations at the Queen’s University Environmental Liner Test Site (QUELTS II) are reported to quantify the onset, progression, and severity of downslope erosion for one particular geotextile-encased, needle-punched GCL for exposure periods of between 7 weeks and 1.3 years. The first significant erosion feature (type “E”with bentonite loss narrower than 2.5 cm) was observed after 6 months of exposure. Irrecoverable erosion features (type “EE” with bentonite loss wider than 2.5 cm) were observed after 12 months of exposure. These findings highlight the need to follow the manufacturer’s recommendations for timely covering of a composite liner with soil following liner installation.

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Shear Behaviour of Geosynthetic Clay Liner (GCL) Interfacing with Manufactured Sand

Lecture Notes in Civil Engineering - Sustainable Environmental Geotechnics ◽

10.1007/978-3-030-51350-4_32 ◽

2020 ◽

pp. 303-322

Author(s):

Anjali G. Pillai ◽

Gali Madhavi Latha

Keyword(s):

Shear Behaviour ◽

Geosynthetic Clay Liner ◽

Clay Liner ◽

Manufactured Sand

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The Influence of Salt Solution on Morphological Changes in a Geosynthetic Clay Liner

Advances in Materials Science and Engineering ◽

10.1155/2016/6349407 ◽

2016 ◽

Vol 2016 ◽

pp. 1-8 ◽

Cited By ~ 3

Author(s):

Mochamad Arief Budihardjo

Keyword(s):

Salt Solution ◽

Morphological Changes ◽

Microscopic Analysis ◽

Optical Microscope ◽

Distilled Water ◽

Nacl Solution ◽

Geosynthetic Clay Liner ◽

Clay Liner ◽

Morphological Variations ◽

Crystal Deposit

Morphological variations of geosynthetic clay liner (GCL) samples, hydrated with two different permeates, distilled water and NaCl solution (100 mM concentration), were observed in detail using microscopic analysis. After the GCL samples were hydrated with the NaCl solution, they were observed with an optical microscope. While the surface of the treated GCL samples was similar to the surface of the untreated GCL, a crystal deposit was found on the surface of the treated samples. Using a scanning electron microscope (SEM), a more solid appearance was observed for the bentonite particles contained in the GCL after the sample was hydrated with distilled water in comparison to the GCL sample that was hydrated with the NaCl solution. It appears that salt solution hydration results in less swelling of the bentonite particles. Furthermore, the energy-dispersive X-ray spectrometer (EDS) results showed that distilled water hydration had no effect on the distribution of the elements contained in the GCL samples. However, bound chlorine was observed, which demonstrated that the bentonite particles had absorbed the NaCl solution. In addition, changes in the hydraulic conductivity of the hydrated GCL samples were also observed.

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