Geosynthetic Clay Liner
The engineering function of a GCL is to act as a hydraulic barrier to water, leachate or other liquids and gases. They are typically used in a composite manner to augment more traditional liner materials such as geomembranes or compacted clay.
Claymat’s Thermal Lock Geosynthetic Clay Liner consists of needle punched geotextile layers encapsulating a layer of sodium bentonite clay. The bentonite clay is then bonded together using either physical bonding or needle punching.
Hydraulic Barrier
Whether used in a landfill, lagoon, or pond, geosynthetic clay liners can provide a hydraulic barrier that limits leakage of liquid and gases. This is important because liquid and gas migration is one of the biggest contributors to environmental damage from landfills.
A GCL consists of a layer of montmorillonitic clay (normally sodium bentonite) sandwiched between two non-woven geotextiles or bonded to a geomembrane. The bentonite clay swells when it comes into contact with water or other liquid, forming a thick barrier with low permeability. GCLs are ideal for landfill lining and capping, canals, reservoirs, highway balancing ponds, and other civil engineering projects that require a containment barrier.
Landfills, for example, require a bottom liner to contain leachate and other contaminants from reaching the overlying soil or groundwater. Because GCLs have a low permeability and high water retention capacity, they perform this function well. This makes them an excellent replacement for compacted clay liners or in a composite manner to augment the more traditional liner materials.
A recent product innovation enables GCLs to be coated with an extruded polyethylene layer. This adds strength, puncture resistance, and other benefits. The result is a highly durable and protective liner that is more resistant to the rigours of the site.
Chemical Retardant
A geosynthetic clay liner can add an extra layer of protection to a spill containment berm. They’re used to prevent a variety of contaminants from seeping out into the environment.
GCLs are typically made from bentonite, which swells when wet and seals any leaks or fractures in the liner. They Geosynthetic clay liner are designed to withstand harsh environmental conditions. In addition to protecting the environment from contaminated water, they also act as a barrier to prevent the release of toxic chemicals into the air.
This liner is a popular alternative to compacted clay barriers because it can be installed more efficiently and has superior engineering properties. GCLs can be used as the sole liner or in a composite design. They’re also more resilient to varying weather conditions and are not affected by the same problems that impact compacted clay liners.
A geosynthetic clay liner is used to protect the environment from contaminating materials that could leak from a landfill waste deposit. It’s a great option for lining waste and leachate landfills, as well as water containment basins. They can also be used to contain coal combustion products (CCPs) from coal-fired power plants. CCPs contain a large number of cations and anions that can release into groundwater. In order to protect groundwater from the contaminating effects of these compounds, new regulations require that disposal facilities incorporate a composite liner of a geomembrane over a soil liner with a hydraulic conductivity of less than 1 x 10-9 cm/sec.
Resistant to Freeze-Thaw Cycles
The high swelling capacity of sodium bentonite makes geosynthetic clay liners (GCLs) an excellent choice for landfill cap applications. GCL technology also provides a viable solution for bottom liner-sand final covers in municipal solid waste landfills. Federal and some state regulations specify design standards for the combination of a GCL with sand in a containment system. GCLs meet or exceed these requirements, and their cost is significantly less than that of a conventional compacted clay layer.
In addition to their superior hydraulic properties, GCLs provide long-term stability against physical or chemical breakdown. These characteristics are particularly important in cold regions where liners and covers may be subject to freeze-thaw cycles throughout their designed life span.
Many GCL products are needle-punched composites that combine a layer of geotextile with a granular sodium bentonite clay core. Upon hydration, the bentonite clay swells to form a tight seal. This self-sealing property allows the GCL to resist damage from environmental conditions, which might otherwise lead to leakage or degradation of the liner system.
Studies have shown that a GCL retains its hydraulic properties through many freeze-thaw cycles, comparable to the performance of a traditional compacted clay liner. However, no literature focuses on the long-term interface shear behavior of a GCL-sand mixture after numerous freeze-thaw cycles. This study addresses this gap in the knowledge base by comparing the hydraulic conductivity of a GCL-sand mixture that has been subjected to multiple freeze-thaw cycles, to that of a mixture that has not experienced any freeze-thaw cycles.
Durable
For industrial applications where the flow of liquids and gases needs to be contained, there are few tools more effective than a geosynthetic clay liner. AGRU GeoClay is a reinforced needle-punched liner that can be installed more efficiently than traditional compacted clay layers, while also providing greater shear strength and durability.
GCLs, as they are often called, are manufactured hydraulic barriers consisting of a layer of low-permeability montmorillonitic clay (normally Geo Bag Sand Bag sodium bentonite) sandwiched between two non-woven geotextiles or bonded to a geomembrane. As a result, they are less susceptible to problems like moisture, drying and tree roots that affect compacted clay barrier systems.
They are commonly used as primary or secondary containment in composite landfill closures, mining leach pads and tailing impoundments and reclamations, as well as for pools and lagoons. Generally, they are more robust than traditional compacted clay layers, and can be installed under high shear and pressure.
The added benefit of a GCL is that it can be reinforced with super-absorbent polymer to improve its durability against wet/dry cycles. The results of wet/dry cycle testing have shown that the inclusion of this material significantly increases a GCL’s ability to resist shear stress, permeability and porosity. In addition, it can help to improve its resistance against damage from chemicals and other contaminants. A secondary containment system can protect your business and the environment from expensive spills and other damages that may otherwise occur if your facility isn’t adequately protected.