15-year test offers variances between EPS and XPS

February 1, 2009  |  Features

ACH Foam Technologies announced in December the completion of a 15-year test to determine water absorption characteristics of EPS (expanded polystyrene) and XPS (extruded polystyrene). The test revealed variances between the two materials in their resistance to water absorption. The test of below-gr…
Researchers test sediment-scrubbing technology

October 1, 2008  |  Features

The testing was conducted at the Cocheco River in New Hampshire. By Beth Potier In a mud flat at the edge of the Cocheco River, just outside downtown Dover, N.H., scientists from the University of New Hampshire’s Contaminated Sediments Center are testing an innovative way to treat polluted sed…
HDPE and PVC

October 1, 2008  |  Features

From the GMA Techline Subject: HDPE and PVC — I am looking for reference material that indicates that HDPE liner and pipes, PVC pipes used in a landfill, are physically and chemically resistant to attack by solid waste and leachate. (Barbara, El Salvador) Reply: You ask a very general question…
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…
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…
Shear strength

October 1, 2008  |  Features

From the GMA Techline Subject: Shear strength — We are looking for interface shear strengths of a geocomposite- to-geocomposite interface. Both composites would have nonwoven fabric. Is test data available that indicates what this interface strength would be? (Chet, Ohio) Reply: The shear stre…
Geotextiles in dams: Forging federal guidelines

August 1, 2008  |  Features

By Douglas A. Crum Abstract The major building era for large dams in the United States, from the 1940s to the 1970s, ended about the time geotextiles were becoming popular. For the last 40-plus years, geotextiles have been used in many dams worldwide for various applications. During this period, fed…
Active LFG control: An unreliable aid to veneer stability

June 1, 2008  |  Features

By Gregory N. Richardson, Stacey A. Smith, and Pieter K. Scheer Abstract The potential for sliding failure of final covers and piggyback liners in municipal solid waste (MSW) landfills equipped with active landfill gas (LFG) control systems is demonstrated and the need for a contingency passive vent…
The GRS bridges of Defiance County

April 1, 2008  |  Features, News

By Michael Adams Introduction Three years ago, the Federal Highway Administration (FHWA) teamed up with local officials in Defiance County, Ohio, to test a new prototype geosynthetic-reinforced soil (GRS) integrated bridge system. Built in 2005, the prototype GRS bridge on Bowman Road in Defiance Co…
Pipeless drainage system

April 1, 2008  |  Features

From the GMA Techline Subject: Pipeless drainage system — We are designing residue cells for a mine in northern Minnesota, and they’ve opted for a pipeless drainage system in the cells. The residue is a very fine, saturated, silt-sized particle, quite sticky, low LL/PL. I’ve done a…