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GMA Techline

February 1, 2018

Determining quantity of recycled HDPE in a geonet Q: I have a question about high-density polyethylene (HDPE) geonets. Is it possible, by thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC) analysis, to determine the quantity of recycled HDPE present in a geonet? I have a geonet that, I think, is made with virgin and recycled …

Part 2: Controlling uplifting gas bubbles in exposed geomembrane-lined ponds

Part 1 of this series in the October/November 2017 issue of Geosynthetics demonstrated how the size, shape, pressure, and stresses and strains experienced by geomembrane bubbles surrounded by a confining fluid could be analytically estimated. Two different field case histories exhibiting the extremes of bubble sizes in ponds lined with 60-mil (1.5-mm) high-density polyethylene (HDPE) …

Geosynthetics: To protect and conserve

December 13, 2017

Geosynthetics are part of a flexible, cost-effective infrastructure that helps to treat, store and deliver clean water around the world. If you’ve had a glass of clean water today, you can likely thank a fabric-based product. Geosynthetics perform behind-the-scenes work to ensure communities have access to adequate potable water and clean waterways. Geosynthetic uses also …

New IFAI chairman Steve Ellington shares his vision for the Industrial Fabrics Association International

November 1, 2017

With the geopolitical challenges and opportunities the specialty fabrics industry faces, we, as an association, need to make sure that we continue to educate our members and provide them with opportunities,” says Steve Ellington, president of Trivantage LLC, Glen Raven’s distribution and marketing services subsidiary in Glen Raven, N.C. “We need to make sure that …

GWFV walls and slopes

October 1, 2017

New patented technology is available to construct geosynthetic wrap-face vegetated (GWFV) retaining walls and reinforced soil slopes using a pyramidal-woven, high-performance turf reinforcement mat (HPTRM) in conjunction with fiber-composite internal braces. This wrap-face system eliminates the need for temporary external bracing (formwork) or for facing elements comprised of metallic wire-frame units, which traditionally have served …

Part 1: Controlling uplifting gas bubbles in exposed geomembrane-lined ponds

There is a substantial legacy of literature devoted to the design, construction and operation of geomembrane-lined ponds, with perhaps the best and most complete reference being 34 years old by Giroud (1983). Even with this long history, there continue to be problems and failures with lined ponds. One of the problems continuing to plague the …

The durability of exposed geomembrane covers

The most frequently asked question by people in the geosynthetics world is how long is the anticipated lifetime of geosynthetics. So much so that of the more than 3,000 questions submitted to the GMA Techline since it began in 2004, 591 (19.7%) have been on lifetime, aka durability. Of these, 49% were on buried lifetime, …

GMA Techline

Welding HDPE to PVC and more Q: I would appreciate any input you have on these questions: Can a high-density polyethylene (HDPE) geomembrane (GM) be welded to a PVC geomembrane? I am looking to connect a geomembrane to a building foundation. Based on some research, I have found the following options: bolt the geomembrane to …

Part 2: The regulation of CCR in the United States: Geosynthetics and barriers

As discussed in Part 1 of “The Regulation of CCR in the United States,” for the first time in decades, nationwide regulation of CCR (coal combustion residuals) surface impoundments expands the regulated use of geosynthetic materials. While the CCR Rule (2015) allows continued operation of existing CCR surface impoundments, it provides criteria for the disposition …

Part 1: The regulation of CCR in the United States: Geosynthetics and barriers

August 1, 2017

The regulation of coal ash (coal combustion residuals or CCR) has significantly expanded the market for geosynthetics within the United States. Further, there is interest in these regulations around the globe in every country using coal as an energy source. These regulations are the result of recent environmental incidents. The regulations call for the increased …