Geosynthetics

 

HDPE- High Density Polyethylene Liners LLDPE – Linear Low Density Polyethylene Liners Reinforced Geomembrane Liners PVC -Poly Vinyl Chloride Geomembrane Liners GCL – Geosynthetic Clay Liners

Geotextiles Dewatering Geogrids Geocomposites Specialty Composites

Geomembrane Liners

Geomembrane liners are impermeable sheets of polymer that are utilized in containment applications. They are available in large custom panels or rolled goods that can be field seamed to form a barrier system. IWT represents a diverse group of geomembrane manufacturers with a large selection of products to suit your requirements. Give us a call for more information. We would be glad to assist in choosing the right product for your application and budget. 

Applications 

• Landfill expansions (cells) 
• Reservoirs, irrigation canals, industrial ponds and lagoons
• Surface impoundments
• Recreational lakes, ponds and golf courses
• Remediation covers or liners
• Alternative daily covers
• Pond/pit liners
• Temporary earthen liners
• Athletic fields
• Brine liners 
• Leachate collection ponds
• Mine tailings & heap leach pads
• Potable water
• Secondary containment of underground storage tanks
• Landfill Liners and caps
• Floating covers

HDPE- High Density Polyethylene Liners
top of page

HDPE is the most widely used geomembrane today. It has been the choice of many for large critical containment applications.

• Resistant to a wide range of chemicals on account of density >.94/cm3 
• Reliable in exposed environment due to high UV protection against degrading and low temperature brittleness
• Typically delivered to the site in large rolls manufactured smooth or textured on one or both sided
• Panels are heat welded in the field by certified technicians providing a high quality, test certified installation. 

Installation Services

With a network of trained and certified installers IWT provides to our customers a one -stop shop for all your geosynthetic needs. Contact us for more information about our liner installation services.

LLDPE – Linear Low Density Polyethylene Liners
top of page

LLDPE is a flexible membrane liner that can conform to any surface even in cold temperature.

• High elongation, tear resistance and burst strength properties
• Contains carbon black and UV stabilizers to enhance longevity and outdoor performance
• Available in large rolled goods manufactured to be either smooth or textured on one or both sided to improve friction. 
• Custom size factory welded panels that are accordion folded and rolled for economical deployment in the field.

Reinforced Geomembrane Liners top of page 
  
 

Dura Skrim reinforced geomembrane liners are produced by extrusion laminating multiple layers of high strength polyethylene with tear resistant polyester scrim.

• Scrim reinforcement enhances strength and resistance to tear
• Excellent longevity in outdoor applications - UV inhibitors and carbon black
• Manufactured and factory welded into large manageable panels 
• Panels are accordion folded and rolled for economical deployment in the field
• Easy to install

PVC -Poly Vinyl Chloride Liners top of page

PVC liners are extremely contractor friendly and offer many advantages over other liners.

• Highly flexible so it easily conforms to sub grade contours. 
• Excellent interface friction properties without being textured
• Excellent puncture and abrasion resistance 
• Superior chemical resistance to acids, alkalis, and alcohols 
• Excellent choice for buried applications to protect from exposure to sunlight. 
• Excellent material for complex sub grades common in smaller application. 
• Available in a variety of formulations including fish grade and oil resistant. 
• Can be contractor installed using PVC glue or Solvent
• Note: losses flexibility in cold weather applications 

GCL – Geosynthetic Clay Liners top of page

GCL’s are composite liners that are manufactured by sandwiching thin layers of bentonite clay between two geotextiles or by bonding them to a geomembrane to form a very thin, tight hydraulic layer. Needle punching or stitching the bentonite between two geotextiles internally reinforces the bentonite and increases the sheer strength of the material. 

• Function is containment of material. 
• GCL liners form a hydraulic barrier layer to liquid movement. 
• High shear resistance.
• Greater installation durability and ease of maintenance.
• Long-term performance in harsh environmental conditions.
• Increased containment volume - significantly reduces the required thickness of compacted clay liners.

Geotextiles top of page

Geotextiles form one of the two largest groups of geosynthetics. They are textiles in the traditional sense but they are from chemically resistant synthetic fibers rather then natural ones thus biodegradion is not a problem.  Fibers are manufactured into a flexible, porous fabric by standard weaving machinery, knitted, or matted together by heat sealing or needle punching to produce a non-woven geotextile.  A major point is that they are porous to water flow across their manufactured plane but their mechanical and hydraulic properties vary widely. 

Functions

• Separation – preventing the mixing of two layers of soil having different particle sizes.  Performance criteria to be concerned with are AOS, Tear, Tensile Strength, Permeability, and Permittivity. 
• Filtration- retaining fine particles while allowing water to flow through geotextile. The geotextile is intended to act like a filter not a drain. Therefore close attention should be paid to performance criteria such as AOS, permeability, and permittivity. The physical properties of the fabric must allow adequate flow, proper soil retention and resists clogging.
• Drainage- to gather liquids or gases that are not required functionally by structure and discharge them. Performance criteria to be concerned with are Mass, Transmissivity, and Permeability.
• Reinforcement- providing a tensile element to the soil matrix and thereby provide more competent structural material .To be effective a geotexile must be able to transfer its strength to the soil it is reinforcing and maintain its strength. It must act as a conduit to allow water to pass through it readily, yet able to filter out fine materials that can weaken the soil. Performance criteria to pay attention to are Grab, Elongation, Tear and Mass. 
• Protection- of synthetic membranes against puncture, abrasion and perforation. Often referred to as a cushion layer. Performance criteria to be concerned with is Puncture, Mass, and Burst Strength. 

Characteristics

• Functions - filtration, separation, and protection
• Excellent physical and hydraulic properties in addition to high tensile strength
• Light weights non-wovens typically used for subsurface drainage applications along highways, within embankments, and athletic fields
• Heavy weight non-wovens cushion and protect geomembranes from damage by sharp objects, elevating puncture, impact and abrasion resistance
• They have also been used for critical subsurface drainage systems soil separation and permanent erosion control.

• Functions- separation, reinforcement, filtration 
• Excellent puncture and tear resistance along with high tensile strengths
• Uniform opening provide excellent flow and filtration characteristics
• Lightweights are typically used for separation of good to moderate sub grades and for controlling run-off and flow velocity. 
• Heavy weight Wovens are typically used for separation and reinforcement and applications such as the stabilization of weak sub grades for heavy loads or if the base material is abrasive.
• Low deformation systems such as paved road on weak sub grades require a product that will increase the bearing resistance of the sub grade as well as provide separation and filtration under long term dynamic loads
• Consider a Woven geotextile with high modulus, high flow and an AOS compatible with sub grade soils

Specialty Wovens

High Strength Wovens

• Functions – reinforcement, filtration, separation
• Properties- immediate load take up with low elongation, low creep and high tensile strengths
• High soil interaction – soil confinement / greater load distribution 
• High percent open area for long term free flowing filtration and drainage
• High seam strength – weak soil conditions and demanding stabilization applications
• High strength geotextile have been used in applications such as retaining walls, landfill liner reinforcement, extra steep earthwork, soil stabilization for rail and road construction, bulkheads, and even underwater

• Functions- Filtration, Erosion Control 
• Manufactured with unique physical and hydraulic properties not possible with standard geotextiles
• These materials allow water to flow through them while filtering or capturing sediment.
• High strengths for durability and survivability
• High percent open area for long-term clogging resistance
• High flow rates
• Excellent for shoreline erosion control, leachate collection systems, drainage and curb inlet filters, geotextile tubes, and geotextile filter bags.

IWT sells a wide range of geotextile products to meet the needs of our clients. Send us your specifications and quantities and we will match the proper product to meet your needs. 
 
 

Dewateringtop of page

Pump Water Filter Bags

A disposable filter bag, manufactured from heavy weight non-woven geotextile filter fabric designed for rapid onsite dewatering of sediments from any water pumping activity. After bulk dewatering takes place, self weight consolidation and confining pressure of the geotextile bag itself continue the dewatering process.  Standard size is 15’ x 15’ with a maximum hose inlet diameter of 8 inches. Other sizes and material available to meet site requirements.

Geotextile Tubes

Geotextile Tubes are usually constructed of high strength permeable woven geotextiles with unique retention properties. They can be custom designed to fit your site parameters.  Fine grain sand, sludge, contaminated soils, or dredge waste materials are pumped into the tubes.  Excess water drains from the small pores in the geotextiles resulting in effective dewatering and efficient volume reduction of the contained material.  Geotextile tubes are a cost effective alternative to traditional sediment dewatering methods. This is an extremely efficient method for containment and dewatering of industrial waste, municipal sludge, and marine sediments. IWT has many years of experience working with geotextile tubes. Give us a call for more information. 

Geogrids top of page

A geogrid is defined as a grid structure of polymeric material formed by weaving or knitting intersecting ribs with appropriate apertures (opening sizes) to allow interlocking with surrounding soil, rock, earth and other surrounding materials. There are two basic categories of geogrids.  Uniaxial geogrids designed to endure stress in one direction. Their main strength is in the machine direction making these grids suitable for wall and slope applications. Biaxial geogrids provide equal strengths in both machine and cross directions making them suitable for bases or foundation application where stresses can occur in any direction. Depending upon manufacturing techniques and materials, geogrids can be designed to resist creep when subjected to high loads for long periods of time or resist high, short-term dynamic loads or moderate loads over longer periods of time. IWT sells a wide variety of geogrids. Need help choosing a grid?  Give us a call. 

Applications

Geogrids focus almost entirely on reinforcement applications, although separation may be a function.  The following are examples of a few applications.

• Slope Reinforcement- embankments over soft soils, extra-steep earthwork slopes, landfill liner systems, and industrial and contaminated land reclamation 
• Base Reinforcement- foundations of roadbeds, parking lots, railroad tracks beds, airports runways, permanent unpaved roads, construction haul roads
• Wall Reinforcement- retaining walls, sea walls, airport noise barriers, and bridge supports 
• Berm Reinforcement - spillway channels for earthen dams, levees, and waste contaminated ponds, banks for earthen canals and waterways

Advantages

• Reduce costs- apertures designed to work with wide range of fill allowing for the use of
  less expensive soils
• Reduce depth of excavation required on unsuitable sub grades
• Increase developable areas without incurring cost of unattractive and expensive retaining wall 
• Stabilizing slopes increases the strength of soil giving it a higher factor of safety and greater
  seismic durability
• Reduces maintenance and extends the life of the pavement by reducing differential settlement
  of roadways 
• Durability – high resistance to soil micro-organisms and chemicals, UV radiation and mechanical damage

Geocomposites top of page

Geocomposites are formed by the bonding of  two or more geosynthetics to achieve specific physical properties such as added protection, drainage, or filtration.  Transnet geocomposite is produced by flame laminating a non-woven geotextile on one or both sides of an HDPE biaxial geonet.  The biaxial design of the geonet provides for high flow characteristics in both machine and cross direction. It also acts as a flow channel for fluids while the geotextile filters and separates to keep soil particles and waste out. Therefore the critical element for geocomposites is Transmissivity or flow rate. 

Functions

• Primary function depends upon final product
• Drainage 
• Separation 
• Reinforcement 
• Filtration 
• Liquid Barrier
• Designed for specialty, critical and or permanent applications

Applications

• Numerous and growing
• Cover systems they inhibit the accumulation of pore-water pressure above the barrier layer by providing a high capacity flow path for the drainage of excess liquids
• Component of gas venting system below the barrier layer to prevent gas build up 
• Replacement to granular leachate collection system 
• Underneath the primary liner as the leak detection layer

Benefits

• Wide range of product combinations- allows for performance driven product selection
• Drainage capabilities are achieved with drainage geocomposites at costs far less than sand and gravel aggregate systems. 
• With the filter, drainage and protection layer being a single unit can be installed rapidly at costs lower than conventional aggregate layers
• Chemical resistance provides long life in harsh environments
• Cost effective replacement to granular drainage systems- cost savings on material, transportation, and installation
• Saves time and natural resources- preserves aggregates resources for structural applications where alternative materials can not be used

Specialty Composites top of page

Geonet/Geotextile

• Separation and filtration functions satisfied 
• Drainage function vastly improved than by using geotextiles alone
• Applications - interception and conveyance of lechate in landfills -conducting vapor or water beneath pond liners

Geotextile/Geomembrane

• Impervious membranes are bonded on one or both sides with a non-woven 
• Function as a barrier and cushion
• Reinforcement applications provide increase resistance to puncture, tear, and friction related to sliding as well as tensile strength
• Heavy weight geotextiles acts as a drainage media since in plane transmissivity feature can conduct water or leachate away from direct contact with geomembrane
• Applications-canal liners, landfill covers and liners and waste water lagoons

Reinforced Non-Woven Composites

• One or more layers of high strength woven combined with a non-woven geotextile to get extreme tensile strength and puncture resistance
• Applications –embankments over soft soils, sub grade reinforcement and asphalt overlay reinforcement

Ultra Heavy Weight Composites 

• Protect landfill liners, railroad sub grade protection, wrap buried pipe
• Applications – environmental drainage control- landfill leachate collection systems and landfill cells 
• Formulated to be used in high load applications 

Disclaimer: These guidelines are for informational purposes only and are intended as illustration or general information only and are not intended as a guarantee or warranty. IWT assumes no responsibilities in connection with the use of this information.

top of page