Geosynthetics support engineered solutions to a range of erosion control, soil reinforcement, drainage, containment, and water storage challenges faced by civil engineers. In response to a request from CE News, companies provided the following information about their products. Company web addresses are provided for immediate access to additional information.
Advanced Drainage Systems (www.ads-pipe.com) provides a full line of erosion control and drainage products, including geosynthetics and geogrids to reinforce weak soil under embankments. Additionally, the company offers silt fences to control runoff and sedimentation, and soil reinforcement blankets and mats to improve water quality by promoting vegetation and providing erosion protection in channels and on slopes.
American Excelsior Company (www.americanexcelsior.com) says its Recyclex turf reinforcement mat (TRM) is the first permanent erosion control mat made from 100 percent recycled post-consumer goods—green or brown bottles. Recyclex contains recycled fibers with 80 percent or more 5 inches long or longer. The fibers are crimped to allow a strong, curled, interlocking fiber matrix. According to the company, crimped fibers conform to terrain details and train water flow to follow the Recyclex curled fiber matrix. In turn, water flow velocity is reduced. Recyclex fibers have a specific gravity of greater than 1.0 so the matrix will not float in a hydraulic event. Recyclex fibers are stitched together by two layers of UV-resistant polypropylene netting to form a 3-D matrix designed to provide permanent surface support for vegetation and structural root systems.
Green Geotextiles from Boom Environmental Products (www.boomenviro.com) are made from rewettable polyester comprising post-consumer recycled plastic bottles. They are available in woven or nonwoven styles. Nonwoven geotextiles, typically used for drainage applications, contain 100-percent post-consumer polyester. Woven geotextiles, typically used for roads, contain 20-percent recycled content per LEED credit 4.2, the company says.
CONTECH Construction Products Inc. (www.contech-cpi.com) says that its TRMs offer permanent erosion protection and provide a cost-effective and environmentally sensitive alternative to paving, rip rap, and concrete linings for slopes and channels. The 3-D, open structure works to entrap soil, retain seeds, and, upon germination, reinforce roots and stems of developing plants. These mats can be incorporated into a stormwater management plan using low-impact development principles.
Firestone Specialty Products (www.firestonesp.com) manufactures geomembrane systems used in a wide variety of containment applications. Firestone EPDM is a highly flexible, stable waterproofing geomembrane that, according to the company, easily conforms to a variety of subgrades. No thermal welding or utilities are required for installation or repair. Panels are seamed together using Firestone’s Quickseam Tape. Firestone’s fPP-R Geomembrane is a scrim-reinforced polypropylene-based membrane with high breaking/tearing strength and puncture resistance. Heat-welded seams and long-term durability make it ideal for both subsurface and exposed geomembrane applications, the company says. Firestone’s fPP-R also meets NSF standards for water purity.
Hancor, Inc.’s (www.hancor.com) selection of specialty products for soil stabilization, reinforcement, erosion control, drainage, filtration, separation, and other construction needs includes fabrics, silt fences, soil reinforcement blankets and mats, plus geogrids, filter socks, and trench liners. Hancor manufactures a wide variety of plastic drainage products for the commercial, residential, construction, and agricultural markets.
Huesker, Inc.’s (www.hueskerinc.com) Fortrac 3D is a turf-reinforcement grid for demanding erosion control applications. Fortrac 3D provides a 3-D array of coated UV-resistant yarns in an engineered grid network that, according to the company, allows for quick establishment of vegetation and protects long-term against erosion of underlying soils. Fortrac 3D is unaffected by freeze-thaw conditions; resistant to chemical, biological, and ultra-violet exposure; and has been developed to reinforce surface soils on steepened slopes, embankments, and landfill cover systems. The company reports that laboratory and field testing confirm that Fortrac 3D has excellent soil interaction properties and high resistance to installation damage.
Layfield Environmental Systems (www.layfieldgroup.com) offers prefabricated vertical drains (also known as PVDs or wick drains) comprising an inner core made out of corrugated polypropylene that is wrapped with a heat-bonded non-woven geotextile. A standard wick drain is 93 mm wide and approximately 4 mm thick, supplied in rolls 152 meters long. PVDs are installed into the subsoil under an embankment to reduce drainage paths and speed consolidation prior to construction. Typically, PVDs are installed in a grid pattern with a spacing range between 1.5 to 2 meters center to center, depending on the compressible layer thickness, the waiting period available, and the loading condition.
North American Green (www.nagreen.com) says its permanent TRMs allow vegetation to be used in areas where flow conditions exceed the limits of natural vegetation, including projects where rock riprap and concrete channels have commonly been specified. Tests reportedly have proven their products to increase the permissible shear stress of many types of vegetation up to 14 pounds per square foot—erosion protection equivalent to that of 30-inch rock riprap and concrete. The company’s permanent TRMs consist of either 100-percent synthetic components (P300 and P550) or a composite of synthetic and natural materials (SC250 and C350). A permanent structure reinforces vegetation at the root and stem level and includes a matrix filler material that provides erosion control immediately after installation. The permanent TRMs are installed in a one-step operation, directly over a prepared seedbed.
Owens Corning’s (www.owenscorning.com/trupave) TruPave engineered paving mat is a non-woven fiberglass/polyester hybrid mat designed to withstand hot-mix asphalt temperatures as high as 495° F without melting, which provides a continuous, non-deforming water-resistant barrier. According to the company, TruPave’s low elongation and immediate tensile strength delays reflective cracking, extends pavement life, and decreases repair and maintenance costs. TruPave is millable and recyclable.
Profile Products LLC (www.profileproducts.com) is the exclusive distributor of Colbond, Inc.’s Enkamat line of TRMs throughout the United States, Canada, and Mexico. According to the company, Enkamat was introduced in 1972 as the world’s first TRM and is the only TRM composed of continuous polyamide strands, thermally fused into a resilient, homogeneous open-mat structure. Profile Products’ GreenArmor System integrates Enkamat TRM, which provides a permanent, lofty and open matrix, with Flexterra Flexible Growth Medium hydraulically applied infill.
Propex Geosynthetics (www.propexinc.com) offers exclusively in the United States NAUE Secugrid and Combigrid biaxial geogrids for soil reinforcement. According to the company, these geogrids do more than just improve the performance of paved or unpaved surfaces; they also save money by reducing construction time and the amount of required aggregate base course material. This, in turn, reduces the amount of excavation and soil replacement. Geogrids can be used to increase the bearing capacity of soils, allow a higher traffic load on the base course, and reduce rutting in a base course. According to the company, these qualities make geogrids a viable solution for road base reinforcement, parking lot stabilization, and storage area support.
According to Seaman Corporation (www.seamancorp.com), its XR Geomembrane products, classified as an ethylene interpolymer alloy, are stable with low thermal expansion-contraction properties. All Seaman geomembrane products come in factory panels greater than 15,000 square feet for less field seaming. They are available in three grades—XR-5 for broad chemical-resistant applications requiring high-strength membranes; XR-3 for moderate chemical resistant requirements in applications such as stormwater and domestic wastewater; and XR-3 PW, which are NSF 61-approved for potable water contact.
Strata Systems, Inc. (www.geogrid.com) announced that its Stratagrid line of geosynthetic products is now offered in 18-foot widths, as compared with standard 12-, 6-, and 4-foot widths. Each Stratagrid panel unfurls to cover 1,200 square yards of subsoil, reducing the number of individual rolls to be installed and seams to be spliced. A simple overlap between ends is all that is necessary to connect two rolls. Stratagrid is made from highly tenacious knitted polyester yarns in an array of grid apertures and strengths. According to the firm, Stratagrid is the first geosynthetic material knitted exclusively from polyester fiber, unrolls flat, and maintains uniform contact with subgrade contours. Bi-directional tensile strength is achieved by placing opposing layers of Stratagrid directly on top of each other with no soil between the layers.
Synteen (www.synteen.com) SF Series Geogrid is composed of high-tenacity, multifilament yarns of high-molecular weight polyester that are coated with a PVC material and woven into a stable network placed in tension. Available grid openings range from 1/4 inch to 3.5 inches. According to the company, SF Geogrids are inert to biological degradation and resistant to naturally encountered chemicals, alkalis, and acids. They provide soil reinforcement in applications such as retaining walls, steepened slopes, embankments, subgrade stabilization, embankments over soft soils, and waste containment.
TenCate Geosynthetics (www.tencate.com) develops and produces Mirafi HP-Series high-performance woven polypropylene geotextiles that function for soil separation, stabilization, and soil reinforcement applications. According to the company, Mirafi HP geotextiles provide higher tensile strength and tensile modulus capabilities than comparable stabilization products and controlled filtration and drainage. Uniform openings allow the geotextiles to handle the same filtration and flow characteristics as that of a fine to coarse sand layer, the company says. Mirafi HP is available in multiple roll sizes that can be sewn together in the factory or in the field for customization to meet project requirements.
Tensar International Corporation (www.tensarcorp.com) expanded its pavement reinforcement capabilities with the addition of the GlasPave Waterproofing Paving Mat from Saint-Gobain Technical Fabrics (SGTF). The GlasPave mat joins SGTF’s GlasGrid Pavement Reinforcement System, used to reduce reflective cracking on highways, runways, and parking lots. Tensar is the exclusive distributor of both products throughout North and South America. GlasPave is composed of a combination of fiberglass mesh embedded into a high-performance polyester fabric, which, according to the company, provides the highest tensile strength at low strain of any comparable product currently available. Its geosynthetic, nonwoven matrix enables an asphalt binder to penetrate and fill voids within the material, limiting the infiltration of surface moisture into a pavement structure.
Watersaver Company Inc. (www.watersaver.com) provides a wide variety of slope stabilization grids, nets, and geotextile products coupled with impermeable geomembrane liners made from PVC, polypropylene, hypalon, and XR-5 PVC alloy. In business since 1953, Watersaver has manufactured more than 1.7 billion square feet of fabrication materials.