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Rub sheets

October 1, 2008 | Products

From the GMA Techline Subject: Rub sheets— What kind of developments are going on these days with rub sheets in leachate sumps with sideslope risers? I’ve seen multiple sheets of geomembrane, but I am more familiar with thick (100- and 120-mil) stock sheet material. Also, what do you thi…

Drainage geocomposite

October 1, 2008 | Features

From the GMA Techline Subject: Drainage geocomposite— I have to test drainage geocomposite material regarding friction behavior and internal shear strength. In terms of references, I see 2 options: friction test (drain material/soil), according to ASTM D5321; and internal shear strength, accor…

HDPE question

October 1, 2008 | Features

From the GMA Techline Subject: HDPE question— I am a high school student doing a science project that is testing the chemical resistance of HDPE. Since we may not be able to test a 60-mil HDPE used in landfills, I was wondering about other products made from HDPE that could serve as a substitu…

Flash point

October 1, 2008 | Products

From the GMA Techline Subject: Flash point— A contractor is proposing installation of a PVC geocomposite in a tunnel as a lining. The California Code of Regulations stipulates the nonuse of materials with a flash point of 100°F or less. Would any of the cements/sealers used in installation…

Teaching geosynthetics

October 1, 2008 | Q&A: GMA Techline

From the GMA Techline Subject: Teaching geosynthetics— I am wondering if you have a list of universities that teach at least one full-time course in geosynthetics. Thank you. (Craig, Pennsylvania) Reply: You have come to the right place! As the author of the only textbook on geosynthetics, I k…

Landfill temperatures

October 1, 2008 | Products

From the GMA Techline Subject: Landfill temperatures — I’ve had discussions with a South African consultant regarding the effects of temperature on the life expectancy of the geomembrane found in South African hazardous landfills. They have tested and found that they are getting temperat…

Break/yield strengths

October 1, 2008 | Products

From the GMA Techline Subject: Break/yield strength —I am a structural engineer working in Chile. I used the following text from your organization: GM13, GM17, and GM19. About GM13 (Rev.8: July 10, 2006), page 10 from this text shows yield strength and break strength for HDPE geomembrane-textu…

Seams on a sideslope

October 1, 2008 | Products

From the GMA Techline Subject: Seams on a sideslope — I am currently reviewing a design for a piggybacked cell that is an extension of a cell that was built 4 years ago. The issue that I am most troubled by is that the 2 cells meet halfway up the slope of an existing landfill. … <div><a…

Alkalinity

October 1, 2008 | Products

GMA techline answers from Bob Koerner Subject: Alkalinity — I am working on a site where there is limestone bedrock. There may be some blasting required that could generate blasted rock fill. Is there a concern with using limestone rockfill with HDPE or polyester-coated geogrids? (Mike, Virgin…

Cheaper products

October 1, 2008 | Products

From the GMA Techline Subject: Cheaper? — We are looking for a manufacturer of geosynthetic bags, tubes, and structures that are small and cheap. (Don, California) Reply: “Cheap” I don’t do very well! That said, if you are looking for a vendor other than the usual manufacture…