Terminology

Warning!!!
The herein below-mentioned part of the standard CSN EN ISO 10318 is published by authority of the Czech Office for Standards, Metrology and Testing. For the office's website - see www.cni.cz

TERMINOLOGY OF GEOSYNTHETIC PRODUCTS

GEOSYNTHETIC (GSY)

A generic term specifying a product where at least one component is made from a synthetic or natural polymer forming a strip, belt or a 3-D structure, used where touching the ground or other materials during grading or other building works. (See EN ISO 10318)

 

GEOTEXTILE (GTX)

Planar, permeable, polymeric (synthetic) or natural textile, either nonwoven, knitted, or woven, used where touching the ground or other materials during grading or other building works. (See EN ISO 10318)

• Nonwoven geotextile (GTX-N)
  Textile made from single-axial or random-oriented fibers, yarn or other elements mechanically punched and/or heatset, or glued (see EN ISO 10318)
• Knitted geotextile (GTX-K)
  Geotextile made by internal looping of one or more yarns, fibers or other elements (see EN ISO 10318)
• Woven geotextile (GTX-W)
  Geotextile made from two or more sets of yarn, fibers, strips or other products usually set at right angles. (See EN ISO 10318)

 

GEOGRID (GGR)

A polymeric structure consisting of regular open network of integrally connected tensile elements bonded by needlepunching, agglutinating, or interlacing; the cells´ nominal area is larger than the components (see EN ISO 10318).

 

GEONET (GNE)

Planar textile with polymeric regular structure consisting of regular dense mesh; its component elements are tied by nibs or needlepunching; the cells´ apertures are much larger than the components (see EN ISO 10318). Geonet does not act as soil reinforcement.

 

GEOMAT (GMA)

A 3-D permeable structure made from polymeric mono-filaments or other elements (synthetic or natural), tied mechanically, chemically, or heatset, or interlaced some other way, used e.g. to prevent down-slope migration of soil particles during turfing, to retain roots or small plants during grading or building works (See EN ISO 10318).

EXAMPLES: A three-dimensional element manufactured by extrusion - heat injection of plastic (PP, HDPE, PA, PET) into a mold.

 

GEOCELL (GCE)

Geocell (cellular system) establishes a system of interlaced textured perforated or smooth belts. These belts are connected by ultrasound welding creating a honeycomb. The cellular system is made from high-density polyethylene HDPE, or polypropylene PP. This system is mostly applied to reinforce a low-bearing base (railroads, highways, dumping yards, etc.), stabilize surfaces of eroded slopes, reinforce stream banks and dikes, and erect retaining walls. For more information - see www.benda-trade.cz

 

GEOSTRIP (GST)

A tape-shaped polymeric material, usually not wider than 200 mm, used where touching the ground or other material during grading or building works (EN ISO 10318).

 

GEOSPACER (GSP)

A three-dimensional polymeric structure designed to form an air cavity in the ground and/or other materials during grading or building works (EN ISO 10318).

 

GEOSYNTHETIC CLAY LINER (GCL)

A factory-made composite consisting of geosynthetic materials and clayey materials with sealing (low filtration) capacity (e.g. bentonite) shaped in strips, used where touching the ground or other material during grading or building works (EN ISO 10318).

 

GEOMEMBRANE (GMB)

Factory-made very low-permeable material made as a synthetic, polymeric or asphalt (bitumen) plate used for grading and building in order to prevent the flow of a liquid and/or vapor through the structure (see EN ISO 10318).

 

GEOCOMPOSITE (GCO)

• A drainage geo-composite (GCO-D). Geosynthetic drainage mats consist of a drainage spatial core overlaid on one or both sides by a filtration geotextile.
  In some cases, geotextile may be fitted with an impermeable layer or even replaced by a foil, adding the insulation capacity to the drainage capacity. The drainage core is usually a geomattress or geonet.
• A geocomposite with the erosion-resistant capacity (GCO-E). An erosion-resistance geosynthetic composite used to prevent surface erosion of soil caused by water or wind; it consists of an erosion-resistant spatial mattress combined with a geogrid, geotextile, or natural biodegradable material (straw, coir, flax, or mixed with grass seeds, as the case may be).
• A reinforcing geocomposite (GCO-R). While placing just one layer, GCO-R allows utilizing the benefits of non-woven geotextile and reinforcing woven or knitted geotextile or geogrid that - by needlepunching or heatsetting - establish a single unit. It is used both for soils (separation and reinforcing) and for asphalt roads (reinforcing), and namely for repairs.
• A protecting geocomposite (GCO-P) utilizes the combination of nonwoven and woven geotextile while gaining better resistance against punching and lower elongation at the lower square weight. The composite consists of two plies of nonwoven geotextiles and one woven geotextile sandwiched in between them. Interlaced either mechanically, heatset, or glued.

 

DEFINITIONS OF INDIVIDUAL TERMS

Weaving
Making sheet textile from one or more systems of linear threads (warp ends) and one or more systems of lateral threads (filling picks), mutually cross-laced on the weaving loom.

Knitting
Making sheet textile from a thread molded in interlaced loops, sometimes using other lacing elements patterned in wales and loops.

Connecting
The process during which are linear or planar elements interlaced at nodal points by welding (laser, ultrasound, heat, etc.) or agglutinating.

Extruding
An extruded belt made from polyolefins is perforated and then, depending on the geogrid, stretched either mechanically or via a system of rolls increasing their rotation speed.

Mechanical reinforcing
Mechanical reinforcing of textile, e.g. by needlepunching, weaving, etc. and/or combination of both (this is not reinforcing by a splicing thread).

Thermal reinforcing
Reinforcing of textile by heat causing the fibers either fuse or contract at points of contact.

Chemical bondage
Reinforcing of textile by a binder creating a compact product by agglutinating or by dissolving some fibers.

Bar
A rib of either eased or square cross-section (e.g. a circle, ellipse, etc.).

Staple
A system of chemical or synthetic fibers of different length and section.

Endless fiber
A linear formation of varied section and chemical or synthetic origin; its length is not limited and is outside the specification of the term staple.

Thread
A textile product of significant length and relatively small section produced from staple or endless fibers, with or without a twist.

Yarn
A thread made from staple fibers, usually connected by a twist.

Fine tow
Linear textile made from endless fibers. Much thinner than a coarse tow, usually of 2,000 - 10,000 dtex linear weight.

Textile or cleaved belt
A flat endless linear formation cut from a textile foil or extruded in to a belt, with a high width/depth ratio, longitudinally cleaved.

Monofilament
A gimp of an unlimited length, without a twist, materially homogenous, its micro-dimensions usually over 0.1 mm.

Plastomer
A macromolecular substance softening and becoming thermoplastic when subjected to heat; solidifying when cooled.

Thermoplastic resin
A plastic material, softening and becoming thermoplastic when subjected to heat, solidifying when cooled.

Thermosetting resin
A plastic material, becoming permanently hard and rigid when heated or cured.

Elastomer
A macromolecular substance swiftly resuming its original shape from which it was formed using slight tensioning (natural and synthetic elastic resin).

Foil
A flat shape of constant depth made by extruding.

Asphalt
Solid bitumen obtained from native deposits or as a petroleum byproduct.

 

DESCRIPTION OF GEOSYNTHETIC PRODUCTS

GEOTEXTILE (GTX)

• Nonwoven textile (GTX-N). Nonwoven geotextiles are generally defined as sheet textiles (fleece) produced by reinforcing mostly textile structural elements, either mechanically, or physically and chemically, or by combining these methods whereas we do not number among nonwoven textiles those produced by weaving, knitting, needlepunching and felting.
• Woven geotextile (GTX-W). Sheet textile made from two perpendicular systems of linear textiles (threads) connected by the weave. Textile is produced on a weaving machine we usually refer to as the weaving loom. We refer to the system of threads forming such fabric as a warp and weft. The warp follows the length of the fabric. The weft consists of threads perpendicular to the warp. The pattern is made up by crossing the warp and weft threads.
• Woven textile (GTX-K). Sheet textile formed from looped interlaced yarn sometimes using also other weaving elements arranged in wales and loops.

 

GEOGRID (GGR)

Geogrids belong among geosynthetic materials maintaining the reinforcing function in the ground structure. In professional practice, we may encounter different types of products of this category varying in the production technology, character of the rib, or type of polymer.

Technical specification:
Geogrids consist of the sheet polymeric structure namely of a system of mostly perpendicular tensile longitudinal and lateral ribs that may be continuously mutually connected at the intersection (Figure #3), welding, gluing (Figure #4) and/or interlacing (Figure #1 and 2); this way are usually established openings 10 - 100 mm large allowing soil/rock particles or other geotechnical materials get through the geogrid's apertures. Geogrids are divided in single-axial and bi-axial:

• single-axial geogrid - strength in one direction strongly prevails in one direction of reinforcement
• bi-axial geogrid - strength in lateral and longitudinal direction does not substantially differ

 

GEONET (GNE)

By their structure geonets resemble geogrids. However, contrary to geogrids, they do not feature equivalent strength properties and thus, in the construction industry, they are used mainly for drainage of liquids or exhaustion of gases. So, their main function is drainage and combined with geotextile they often form a geocomposite.

Technical specification:
In most cases, ribs of geonets, contrary to geogrids, intersect at different than right angles and they are intended for drainage of liquids or exhaustion of gases. Geonets may be divided as follows:

• bi-directional geonet - two ribs meet in a nib (Fig. #13, Fig. #14)
• three-directional - three ribs meet in a nib

 

GEOCELL (GCE)

Geocell (cellular system) is a system of interconnected surface textured perforated or smooth strips. These strips are connected by an ultrasound weld in order to form a honeycomb pattern. The cellular system is made from a high-density polyethylene HDPE, or polypropylene PP. This system is mostly applied to reinforce a low-bearing base (railroads, highways, dumping yards, etc.), stabilize surfaces of eroded slopes, reinforce stream banks and dikes, and erect retaining walls. For more information - see www.benda-trade.cz