New GSI test method for resistance of conductive geosynthetics

June 1st, 2022

The Geosynthetic Institute (GSI) has a new test method for resistance measured across positions on conductive geosynthetics. Conductive geosynthetics contain an electrically charged backing (usually a thin layer of polyolefin with letdowns containing 20%–30% carbon black) that allows leaks to be detected in lined systems without the need for a conductive subgrade beneath the liner […]

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GSI Lifetime Predictions of Nonexposed and Exposed Geosynthetics webinar June 8

May 31st, 2022

Photograph courtesy of Solmax The Geosynthetic Institute (GSI) will sponsor a webinar, “Lifetime Predictions of Nonexposed and Exposed Geosynthetics,” on June 8, from 11:30 a.m. to 1 p.m. EDT. Geosynthetic Materials Association (GMA) member companies and their employees receive discounted rates on all GSI webinar and short course registrations. Learning objectives of the webinar Webinar […]

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GSI landfill covers webinar upcoming

April 26th, 2022

GSI landfill covers webinar on May 11 will focus on the various components included in geosynthetic final covers for solid waste landfills. Geomembrane landfill cover, one type of emerging geosynthetics to be discussed in the GSI landfill covers webinar. Photograph courtesy of Layfield Group Ltd. The Geosynthetic Institute (GSI) will sponsor a webinar, “Landfill Covers: […]

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Layfield’s Fraser joins GSI board

April 20th, 2022

Layfield’s Fraser joins GSI board of advisors, bringing his 40+ years' experience in the geosynthetics industry to GSI. Brian Fraser joins GSI board of advisors. Photograph courtesy of Layfield Group Ltd. The Layfield Group Ltd. announced that Brian Fraser, vice president of business development for Layfield Geosynthetics, has been appointed to the Geosynthetic Institute (GSI) […]

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Geosynthetic Institute landfill failure webinar upcoming

April 8th, 2022

Geosynthetic Institute landfill failure webinar on April 20 will focus on 20 lined and unlined municipal solid waste (MSW) landfill failures. A recent installation of a geosynthetic clay liner (GCL) at a landfill in Australia. Photograph courtesy of Geofabrics Australasia Pty Ltd. The Geosynthetic Institute (GSI) will sponsor a webinar, “Behavior and Analysis of Twenty […]

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Methane gas geomembrane permeability

April 1st, 2022

Q: What is the least permeable geomembrane to methane gas? Regarding the permeability of geomembranes to methane gas, could you send me some technical guidelines? A: High-density polyethylene (HDPE) geomembranes are denser (more crystalline) than linear low-density polyethylene (LLDPE) geomembranes and less permeable. The water vapor, solvent and methane transmission (diffusion) of an HDPE barrier […]

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Scratch impact on HDPE liners

April 1st, 2022

Q: I have a project where multiple and extensive scratches were created on the high-density polyethylene (HDPE) liner for a reservoir due to poor construction practices. (See the following Figures 2–4.) FIGURE 2 Construction equipment that caused scratches at crest of slope FIGURE 3 Overview of scratches in 60-mil (1.5-mm) high-density polyethylene (HDPE) conductive liner […]

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New GSI method for strain hardening of HDPE geomembranes

April 1st, 2022

Traditionally, high-density polyethylene (HDPE) geomembranes are checked for stress crack resistance using the ASTM D5397 single point-notched constant tensile load (SP-NCTL) test (Hsuan, Lord and Koerner [1990]). This test uses notched specimens, surfactant, and elevated temperatures to accelerate the behavior and force a brittle failure in HDPE geomembranes. With today’s high stress crack resistant HDPE […]

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Welding HDPE geomembranes with biogas present

April 1st, 2022

Q: We are a Brazilian company specializing in biogas plants. We have built a big lagoon biodigester with a high-density polyethylene (HDPE) geomembrane cover. Now the cover is leaking liquid contained in the lagoon: We are organizing the repair procedure, and we would like to first investigate state-of-art practices and procedures for welding HDPE geomembranes […]

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NSF 61-certified HDPE geomembranes

April 1st, 2022

Q: Hi, we are looking for options for NSF 61-certified high-density polyethylene (HDPE) liners for installation in a potable water tank, 95th-percentile concentration of free chlorine in the tank is 1.2 ppm (1.2 mg/L). The current liner (60-mil [1.5-mm] textured HDPE, installed in 1999) is damaged and needs to be repaired or replaced. We are […]

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