Chemical interaction and hydraulic performance of geosynthetic clay liners isothermally hydrated from silty sand subgrade

2019 ◽  
Vol 47 (6) ◽  
pp. 740-754 ◽  
Author(s):  
R. Kerry Rowe ◽  
J.D.D. Garcia ◽  
R.W.I. Brachman ◽  
M.S. Hosney
Keyword(s):  
Chemical Interaction ◽  
Hydraulic Performance ◽  
Silty Sand ◽  
Geosynthetic Clay Liners ◽  
Clay Liners

Hydraulic performance of geosynthetic clay liners under gravel cover soils

2000 ◽  
Vol 18 (2-4) ◽  
pp. 179-201 ◽  
Author(s):  
Patrick J Fox ◽  
Daniel J De Battista ◽  
David G Mast
Keyword(s):  
Hydraulic Performance ◽  
Geosynthetic Clay Liners ◽  
Clay Liners

Insight into hydraulic conductivity testing of geosynthetic clay liners (GCLs) exhumed after 5 and 7 years in a cover

2017 ◽  
Vol 54 (8) ◽  
pp. 1118-1138 ◽  
Author(s):  
R.K. Rowe ◽  
R.W.I. Brachman ◽  
M.S. Hosney ◽  
W.A. Take ◽  
D.N. Arnepalli
Keyword(s):  
Hydraulic Conductivity ◽  
Unit Area ◽  
Divalent Cations ◽  
Hydraulic Gradient ◽  
Silty Sand ◽  
Geosynthetic Clay Liners ◽  
Clay Liners ◽  
Percentage Area ◽  
Bundle Size ◽  
Insight Into

Four geosynthetic clay liners (GCLs) serving as single liners were exhumed from below 0.7 m of silty sand on a 3:1 (horizontal:vertical) north-facing slope at the QUELTS site in Godfrey, Ontario, after 5 and 7 years. The 300 mm GCL overlaps with 0.4 kg/m supplemental bentonite were all physically intact. The exchangeable bound sodium was completely replaced with divalent cations. The GCL with the smallest needle-punched bundle size (average of 0.7 mm) and percentage area covered by bundles (4%) maintained low hydraulic conductivity (k) when tested under 0.07–1.2 m head with 10 mmol/L CaCl2 solution as the permeant. For GCLs with larger bundles (1.1–1.6 mm) and higher percentage area covered by bundles (9%–14%), k was low when the head was low (0.07 m). Once the applied head increased, k increased by 1–4 orders of magnitude depending on the (i) hydraulic gradient, (ii) size and number of the needle-punched bundles, and (iii) structure and mass of the bentonite per unit area. The results suggest that the GCLs can perform effectively as a single hydraulic barrier in covers providing that the head above the GCL is kept low (e.g., by a suitable drainage layer above the GCL).

A study on the hydraulic performance of sandwich geosynthetic clay liners reinforced with nano-clay particles

2016 ◽  
Vol 18 (6) ◽  
pp. 693-711 ◽  
Author(s):  
Niloofar Salemi ◽  
Sayyed M Abtahi ◽  
Mohammadali Rowshanzamir ◽  
Sayyed M Hejazi
Keyword(s):  
Hydraulic Performance ◽  
Geosynthetic Clay Liners ◽  
Clay Liners ◽  
Clay Particles ◽  
Nano Clay

Field measurements of overlap reductions for two reinforced fabric-encased geosynthetic clay liners (GCLs)

2018 ◽  
Vol 55 (5) ◽  
pp. 631-639 ◽  
Author(s):  
R. Kerry Rowe ◽  
Richard W.I. Brachman ◽  
W. Andy Take
Keyword(s):  
Dominant Role ◽  
Field Measurements ◽  
Silty Sand ◽  
Geosynthetic Clay Liners ◽  
Clay Liners ◽  
Side Slope ◽  
Flat Base ◽  
Composite Liners ◽  
Hydration And Dehydration ◽  
Test Embankment

Two geosynthetic clay liners (GCLs) reported to have experienced significant shrinkage at other locations are examined on both a 3H:1V south-facing slope and a relatively flat base on a silty sand. The GCLs were overlapped by 300 mm with 400 g/m of supplemental bentonite and covered by a black 1.5 mm high-density polyethylene (HDPE) geomembrane to form a composite liner that was left exposed in a full-scale field test embankment for a period of almost 5 years. It is shown that despite the relatively uniform exposure conditions, shrinkage is highly variable with a maximum shrinkage of GCL A being 165 mm on the slope and 415 mm on the base while GCL B shrunk by up to 75 mm on the side slope and only up to 25 mm on the base. The dominant role played by variable overlap stick and heterogeneity to the locations where the overlaps are re-wetted are discussed. Based on this study of shrinkage and a related study of downslope erosion at the same site, it is concluded that neither GCLs A nor B should be left in exposed composite liners when they can be subjected to thermal cycles that can lead to hydration and dehydration of the GCL.

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