Geotextile impact testing

June 1, 2022  |  Q&A: GMA Techline

Q: We would like to carry out an impact test on geotextiles as described in Koerner (2012), Chapter 2.3.3 Mechanical Properties-Impact Test and Chapter 2.5.5 Impact (Tear) Resistance. I came across the Geosynthetic Research Institute (GRI) GS2 Test Method for Rupture Strength of Geosynthetics by Pen…
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Welding HDPE geomembranes with biogas present

April 1, 2022  |  Q&A: GMA Techline

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…
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NSF 61-certified HDPE geomembranes

April 1, 2022  |  Q&A: GMA Techline

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 a…
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Impregnation of GCLs

April 1, 2022  |  Q&A: GMA Techline

Q: We are confused with the term “impregnation” as it relates to seaming geosynthetic clay liners (GCLs). There are two types of impregnations: (1) Edge impregnation, and (2) complete nonwoven (cap layer) impregnation of GCLs. How does a manufacturer do this?
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GCL-GM geocomposite: Which end is up?

April 1, 2022  |  Q&A: GMA Techline

Q: In a geosynthetic clay liner-geomembrane (GCL-GM) geocomposite, does it make any difference which side of the geocomposite is up: GM or clay?
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Calendared nonwoven geotextiles

April 1, 2022  |  Q&A: GMA Techline

Q: What is the difference between normal nonwoven and calendared nonwoven (both needlepunched) geotextiles? Where can we use calendared nonwoven geotextiles?
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LCC curing effect on geogrids

April 1, 2022  |  Q&A: GMA Techline

Q: Can you tell me whether modest warming of geogrids (e.g., due to heat generated by the curing of lightweight cellular concrete [LCC]) might impact the long-term strength or long-term modulus of geogrids?
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High pH effects geogrids?

April 1, 2022  |  Q&A: GMA Techline

Q: Can you tell me whether the high pH of curing portland cement (typically ~12.4) might have any impact on the long-term performance of geogrids?
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Methane gas geomembrane permeability

April 1, 2022  |  Q&A: GMA Techline

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?
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Scratch impact on HDPE liners

April 1, 2022  |  Q&A: GMA Techline

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.)
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