The GMA Techline

August 1st, 2019

Moderated by Robert M. Koerner, George R. Koerner and Y. “Grace” Hsuan A geotextile for unpaved driveway/road? Q: Is there any point in using a 150 g/m2 (4.4 oz/yd2) nonwoven geotextile in building an unpaved gravel driveway or gravel road? If so, what should be the most important characteristics of the fabric and what are […]

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The GMA Techline

June 1st, 2019

Who is doing the testing? Q: This question relates to the number of rolls to be selected as the lot sample for specification conformance testing and refers to ASTM D4354. When I look at this standard, it appears the values in Table 1 of GRI’s White Paper #10 refer to the number of units to […]

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The GMA Techline

April 1st, 2019

Vegetation causing gases under geomembrane? Q: I have a site where we are installing a high-density polyethylene (HDPE) liner in an existing pond. Because of some residual heavy metals in the top layer of soil, I would like to strip off the top 3–6 inches (7.6–15.2 cm) of soil and vegetation. Alternatively, we could mow and […]

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The GMA Techline

February 1st, 2019

Geomembranes for canal lining Q: Our company is an international member of the Industrial Fabrics Association International (IFAI). Our government is planning to line their water canals with a geomembrane to prevent water seepage into the soil. We have been approached by many to suggest the most suitable material with specifications to guide them in […]

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The GMA Techline

October 1st, 2018

Toxicity of nonwovens? Q: Are there any comprehensive tests (or a general synopsis) of the environmental toxicity of leachate from nonwoven polypropylene fabrics when aged in a freshwater or saltwater solution? Regulatory and municipal bodies in Europe and New Zealand are requesting more info about products that are used in riparian and coastal environments. A: […]

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Dr. Robert M. Koerner answers your geosynthetics questions

June 5th, 2018

Get your technical geosynthetics questions answered by one of the world’s leading experts on geosynthetics through the GMA Techline. View past questions and answers at https://tinyurl.com/GMATechline. Email gmatechline@ifai.com anytime for fast, direct answers to any and all technical geosynthetics questions. This one-of-a-kind resource is free to all courtesy of the Geosynthetic Materials Association (GMA), Geosynthetics magazine and the […]

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Your geo technical questions answered on the GMA Techline

March 1st, 2018

Looking for answers to your geosynthetics technical questions? Contact the Geosynthetics Materials Association (GMA) Techline for thorough answers to the most detailed questions. Everything from measuring puncture resistance to the chemical effects of fracking flowback on HDPE geomembranes has been addressed by the GMA Techline. Dr. Robert M. Koerner and Dr. George Koerner of the […]

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GMA Techline

October 1st, 2017

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 […]

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GMA Techline

August 1st, 2017

Liner repair? Pullout tests? Sewn seams? Shear strength of sludges? Geomembrane liner repair Q: I have a facility that has submitted liner repair documentation for the repair of a high-density polyethylene (HDPE) liner for a leachate/stormwater pond at an industrial landfill site. The repairs were performed using either a patch or, for indentations and small […]

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Your geo questions answered on the GMA Techline

June 7th, 2017

Looking for answers to your geosynthetics technical questions? Contact the Geosynthetics Materials Association (GMA) Techline for thorough answers to the most detailed questions. Dr. Robert M. Koerner, who has more than 40 years of experience teaching, writing about, researching, and consulting on geosynthetics, responds to questions that range from which geosynthetic to use for a […]

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