The influence of soil type on interface behavior under pullout conditions

June 1, 2014  |  Features

Part 3: European experience in pullout tests By Nicola Moraci, Daniele Cazzuffi, Lidia Sarah Calvarano, Giuseppe Cardile, Domenico Gioffrè, and Piergiorgio Recalcati 1. Introduction The rapid increasing application of geosynthetics as reinforcement elements for earth structures requires a car…
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Long-term pavement testing by FHWA

April 1, 2014  |  Features

Contamination by subgrade soil causes deterioration in pavements from progressive loss of effective aggregate base thickness. Introduction A major deterioration factor in pavements is the progressive loss of effective aggregate base thickness because of contamination by subgrade soil. In the service…
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ASTM geosynthetics standards revising to ISO ‘geo terminology’

October 1, 2013  |  Features, News

By Bob Mackey Geo terminology—The current issue The ASTM Committee D35 on Geosynthetics was established to develop standards on test methods, guides, practices, and specifications for geosynthetic materials. A component critical to the development of these standards is an agreement within the …
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Market impacts for geosynthetics from the regulation of coal ash

August 1, 2013  |  Features, News

By Boyd Ramsey and Andrew Aho Authors’ note to readers: This is a fast-moving topic where situations change as time and political positions evolve. It is the authors’ intent to report on the current situation and implications “at the time of presentation [April 2013],” provid…
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Air-channel testing of thermally bonded flexible polypropylene geomembrane seams

April 1, 2013  |  Features

By Timothy D. Stark, Richard W. Thomas, and Thomas J. Dehlinl Introduction For more than a decade, thermal welding has proven to be an efficient and cost-effective procedure for field-seaming geomembranes. Thermal welding of polyvinyl chloride (PVC) geomembranes has allowed use of air-channel tests …
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Recognizing the benefits of GRS bridge-building technology

August 1, 2012  |  Features, News

Take the leap of faith By Jessica Bies Introduction More than seven years after the Federal Highway Administration (FHWA) and local officials in Defiance County, Ohio, built their first geosynthetic-reinforced soil (GRS) integrated bridge, county engineers throughout the U.S. are starting to recogni…
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ASTM D6637–11 standard test method

November 10, 2011  |  Features

The determination of the tensile force-elongation values of geogrids provides index property values. This test method is used for quality control and acceptance testing of commercial shipments of geogrids. In cases of dispute arising from differences in reported test results when using this test met…
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ASTM D7747–11 standard test method

November 10, 2011  |  Features

The use of reinforced geomembranes as barrier materials has created a need for a standard test method to evaluate the quality of seams produced by thermo-fusion methods. This test method is used for quality control purposes and is intended to provide quality control and quality assurance personnel w…
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New ASTM geosynthetic practice standardizes leak-detection method

November 10, 2011  |  Features

A new ASTM International practice standardizes a geoelectric method used to detect potential leaks in exposed electrically isolating membranes in the field in containment applications. The new standard, ASTM D7703, Practice for Electrical Leak Location on Exposed Geomembranes Using the Water Lance S…
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Leak location

October 1, 2011  |  Features

From the GMA Techline RE: Leak location I have been reading though the GSI White Paper #8 regarding the CQA method. I am designing a reservoir that will be around 50ft deep and has many 2:1 sideslopes (uncovered 60-mil HDPE liner) that I would also need to test for leakage. It doesn’t seem tha…
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