Geosynthetic products manufacturer and supplier Fibertex South Africa (SA) distributes a comprehensive range of NAUE Geosynthetics products designed for use as efficient sealing barriers, in a range of diverse applications, including construction projects.

The geosynthetic clay liners (GCLs) include the Bentofix and Bentofix X range. Bentofix GCLs typically include a nonwoven polypropylene (PP) cover geotextile and a nonwoven and/or woven tape PP carrier geotextile, explains Fibertex SA national sales manager Darryn Meisel. The carrier geotextile of the Bentofix X is coated with an additional, low-permeability polyethylene (PE) layer.

With the additional bonding of a PE coating, the needle-punched fibre reinforcement is more permanently locked further increasing the internal shear strength, interface friction and stability in steep-slope applications through its structured outer surface.

Meisel explains that the Bentofix X enhances the available factor of safety and confidence in products and their applications for design engineers.

He notes that the addition of the PE layer exemplifies how modifications to geosynthetic product design can be made to anticipate exactly what the design engineer requires to effectively deal with the specific challenges of every site, such as liquid loss into the underlying ground, migration of contaminants, protection of subsoil structures and, subsoil structure waterproofing.

The Bentofix GCLs are used as replacements for conventional compacted clay layers during a project; when hydrated with water, the bentonite swells and forms a low-permeability gel layer, with improved hydraulic performance over traditional, thick compacted clay liners.

The needle-punched process and ‘thermal lock’ manufacturing technology increases the internal and external shear strength of GCLs, creating a single, engineered barrier that uses the best of synthetic and natural materials, and expands the range of applications in which GCLs can be used, Meisel enthuses.

The self-sealing Bentofix, he notes, can also be used as a root barrier, waterproofing membrane, a protection layer for the storage of liquids or as a barrier preventing the migration of adverse contaminants in either gas or liquid form.

As a barrier, Bentofix GCLs can, in certain instances, also replace geomembranes or plastic sealing mechanisms.

Bentofix GCLs are needle- punched, reinforced composites which combine two durable geotextile outer layers and a uniform core of high-swelling powder sodium bentonite clay, which forms a uniform, multi- directional, shear-resistant hydraulic barrier with self-sealing and rehealing characteristics.

Bentofix X GCLs can be installed where a prompt barrier against gas is necessary, desiccation needs to be permanently avoided and protection against root penetration is required.

Other applications include the prevention of the erosion of the bentonite, owing to high water heads, and the requirement of a supplementary barrier against critical liquid migration.

Other NAUE geosynthetic products available from Fibertex locally include the Secugrid range of fourth-generation geogrids, comprising durable biaxial and uniaxial, polyester and PP high-strength geogrids.

“Secugrid geogrids are suitable for all civil engineering applications, including environmental, infrastructure, mining and marine engineering projects,” Meisel notes.

Fibertex SA supplies an extensive range of environment-friendly geosynthetic products from its KwaZulu-Natal, Gauteng and Western Cape facilities that encompasses nonwoven and woven geotextiles, gabions and mattresses, subsoil drainage pipes and fittings, erosion-control mechanisms, cuspated sheets, subsoil drainage systems and cellular confinement solutions.

The company also supplies soil and asphalt reinforcing products, including geogrids and geocells, as well as geosynthetic clay liners and geomembranes as part of composite lining systems used in modern landfills and other environmental-protection applications.