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Bentomat linear

We are looking at using a regular liner. Are there any advantages of switching to Bentomat?

Yes, see the Comparison Table


How much Bentomat will I need?

Use the Bentomat Calculator to work out how many rolls / half rolls your project will require - Click Here


Is my project going to be very expensive using Bentomat?

No. Usually, even though Bentomat has many advantages over regular liner, your project works out substantially cheaper.


Are there any specialist installers of Bentomat?

No. Simply because there are no expertise involved in the installation of Bentomat, its extremely straightforward. Full Installation Guidelines are provided with each order.


What is the lifetime of a GCL?

To the best of our knowledge, the natural and synthetic components of a GCL will uphold far into the future, likely over 100 years under normal conditions of soil burial. While conclusive data is impossible to provide, the bentonite in GCLs is already extremely old (millions of years), and the synthetic geotextiles are made of chemically stable polymers which resist long-term degradation.


What equipment do I need to unload the delivery vehicles?

When GCL rolls arrive via flatbed trucks, the trucks are best unloaded using the slings included with each roll. Other alternatives include using an articulating lift truck equipped with a “stinger” which is pushed through the roll core, or a steel core pipe can be inserted manually and the rolls lifted using an excavator or crane.


How strong is BENTOMAT?

Nearly all BENTOMAT GCLs are reinforced, in which the fibers of a non-woven geotextile are needle-punched through the bentonite layer into either a woven or non-woven geotextile (depending on the product configuration). The needle-punched fibers give these BENTOMAT products excellent internal shear strength for use in sloped applications.


Are GCLs affected by freeze/thaw?

Geosynthetic clay liners are not adversely affected by freeze/thaw cycles. Laboratory testing has shown that the hydraulic conductivity of GCLs remains unaffected after many freeze/thaw cycles.


What is the steepest slope on which BENTOMAT may be used?

Reinforced BENTOMAT GCLs have been successfully used on slopes 4H:1V. These designs were based on internal and interface direct shear testing.


The contractor has requested permission to use cover material that contains limestone or dolomite. Should I be concerned?

Calcium and magnesium can leach from cover material and exchange with the sodium ions in the sodium bentonite used in GCLs thus reducing its efficiency. As a general guideline, calcium-rich cover materials are NOT recommended.


What is the difference between flux and permeability?

Flux is the actual rate of flow through the GCL and is expressed in units of volume per unit area per unit time (m3/m2/sec). Permeability or hydraulic conductivity is a mathematical constant derived from Darcy’s Law and describes a soil’s ability to convey flow under known hydraulic forces. The benefit of using flux is that this value can be used for a direct comparison to any maximum leakage specifications or requirements for a given project.


Is a GCL compatible with organic chemicals?

In general, yes. Small concentrations of common organic groundwater contaminants, for example, have no effect on the hydration and function of a GCL. However, we would recommend both soil and water samples be taken for analysis to ensure minerals such as Calcium are not present which can inhibit cation exchange and the Sodium Bentonite's ability to seal.


Are GCLs compatible with landfill leachate?

Many laboratory hydraulic conductivity tests have been performed on specimens of GCLs with leachate as the permeant. This testing has shown that hydraulic conductivity generally remains unchanged.


How long do GCLs take to hydrate?

When a geosynthetic clay liner is placed on a soil, it will hydrate through absorption of moisture contained within the adjacent soil. Testing results show that the GCL will even hydrate when placed on a soil with a moisture content well below optimum.


What is the typical moisture content of the bentonite in Bentomat GCLs?

The moisture content of raw bentonite, before it is incorporated into the GCL, is less than 12%. During manufacturing of the GCL, water is added to the bentonite to assist GCL needle-punching. The resulting bentonite moisture content in BENTOMAT leaving our manufacturing facilities is between 25% and 40%, with typical values of about 30%. These values are well below that of fully hydrated bentonite, and will have no negative effect on performance. In fact, bentonite with 25% to 40% moisture has the appearance, consistency, and strength of a granular soil.


Should I be concerned about GCL panel separation in the field?

Separation of overlapped GCL panels may be a concern in "exposed" lining systems - situations where a GCL is left covered only by a geomembrane with no confining cover soil for extended periods of time (months or years). Under these conditions, there have been some documented instances where wide temperature fluctuations in the exposed geomembrane compromised the underlying GCL seams, resulting in gaps between the panels. However, reasonable measures can be implemented to prevent panel separation.


Will BENTOMAT GCLs shrink in the field upon deployment?

Both laboratory and field data have demonstrated that BENTOMAT deployed at its as-manufactured moisture content (25% to 40%) will not shrink upon drying. Thiel (2005) found that GCLs can experience shrinkage when subjected to repeated cycles of wetting and drying (full hydration followed by complete desiccation). However, reasonable measures can be implemented to prevent this from occurring.