Factors affecting GCL hydration under isothermal conditions

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

“…It is known that the uptake of moisture by a GCL is dependent on the initial water content of the subgrade (Rayhani et al 2011;Benson 2013;Siemens et al 2013), the subgrade particle size distribution and mineralogy which both affect the subgrade water retention characteristics (Anderson et al 2012;Sarabian and Rayhani 2013;Bouazza et al 2016), the hydraulic conductivity of the subgrade (Chevrier et al 2012), the water retention characteristics of the GCL (Beddoe et al 2011), and the nature of thermal cycles (Rowe et al 2011b). At this site the soil had a relatively uniform mineralogy, particle size, and initial water content although there was some variability from location to location (with the western half of the site being a little siltier with higher initial water contents than the eastern half of the site which was generally sandier with lower initial water contents; ) however since GCL B was placed at both the eastern and western ends of the site and GCL A was located toward the centre of the site, this variability does not appear to offer an explanation for the observed behaviour.…”

“…This paper is focused on shrinkage of two GCL products in the composite liner on the 3H:1V south-facing slope together with a 20-m wide and 80-m long (3% slope) base portion ( Figure 1). The embankment fill and the base were native silty-sand (SM) with an average nonplastic fines content of 40% (i.e., % by mass passing the 0.075 mm sieve with dry sieving) with a range between 32 and 46% (Brachman et al 2007), and a standard Proctor (ASTM D 698) optimum moisture content of 11.4% (Rayhani et al 2011). The initial subgrade water content ranged between 12 to 21% and the dry densities between 1500 to 1700 kg/m 3 .…”

Gas permeability of partially hydrated geosynthetic clay liner under two stress conditions

“…Anderson et al (2012), Rayhani et al (2011) and Singh and Bouazza (2013) defined the apparent degree of saturation as the gravimetric moisture content (w) of a GCL (both geotextile and bentonite contribution) at a given time divided by the maximum gravimetric moisture content (wref) that the same GCL can reach during hydration under the same applied stress conditions. Figure 5 indicates that wref under 2-kPa (50 days hydration) and 20-kPa (90 days hydration) stressed specimens were 168% and 163%, respectively.…”

“…Generally, it is expected that passive hydration will begin at the time of installation and should be complete prior to significant contact with gas (Anderson et al, 2012;Rayhani et al, 2011). However, there is no guarantee that the GCL will reach full hydration (Buckley et al, 2012;Meer and Benson, 2007), and the potential for the GCL to be unsaturated when needed to control gas migration requires consideration.…”

Studies of the Solar Radiations' Influence About Geomembranes Used in Ecological Landfill

“…The temperature which exist at the mounting of the geomembrane is a very important element because a high temperature lead at the inevitable appearance of the plies and these plies could have important consequences regarding the functioning and impermeability of the ecological landfill [11,12].…”