Members Only  

HDPE & LLDPE rates

June 1, 2011

From the GMA Techline RE: HDPE & LLDPE rates I have always been under the impression that in using field tensiometers on jobsites that the rates for HDPE and LLDPE are different —HDPE at 2in./min. and LLDPE at 20in./min. However, I don’t have any documentation to back this up. Can you provide me with any …

Members Only  


October 1, 2010

From the GMA Techline RE: GG3-87 I was wondering if guideline GG3-87 is still in use. If it is, could I get a copy? Thank you. (Jason | Kentucky) Reply: Good question and, as with many other GRI Standards, we have given the GRI method to ASTM, which now has a replacement. The replacement for …

Members Only  


From the GMA Techline RE: GM13 We request you to kindly send us the GRI-approved grades for manufacturing HDPE geomembrane as per GM13. (Dilip | India) Reply: The GRI GM13 specification is a template of required properties for a manufacturer to meet or exceed. If your geomembrane does indeed meet the requirements, you can say …

ASTM standards for material properties for pavement components

July 1, 2010

Two new ASTM International standards will aid in the recent national movement to develop a mechanistic-empirical design guide for pavements. Both new standards, developed by ASTM International D35 on Geosynthetics, will cover quantification of fundamental material properties for pavement components. The standards, ASTM D7499, Test Method for Measuring Geosynthetic-Soil Resilient Interface Shear Stiffness, and ASTM …

Updating specs: ASTM D4833 replaced by D6241

February 1, 2010

Neither Mullen Burst Strength ASTM D3786 nor Puncture Strength ASTM D4833 is recognized by ASTM Committee D35 on geosynthetics as an acceptable geotextile test method. Also, AASHTO M288 has recently (M288-05) replaced ASTM D4833 with the Static (CBR) Puncture ASTM D6241. Starting in 2010, ASTM D4833 and D3786 will no longer be published by GMA …

Members Only  

GSI/GRI-GG5 and ASTM D6706

October 7, 2009

GMA techline answers from Bob Koerner Subject: GG5 I referenced GSI/GRI–GG5 on a segmented retaining wall system spec and need to know if this is correct. Supposedly on your website this standard was crossed out and noted to refer to ASTM D6706. Should I replace GG5 with the ASTM standard? Please clarify. (Rebecca, New Jersey) …

Members Only  

The difference between strength parameters

June 1, 2009

By Timothy D. Stark Q: What is the difference between the strength parameters c and ø, and a and δ? A: Good question because these parameters are frequently used interchangeably. c and ø, and a and δ are shear strength parameters used to represent the strength/failure envelope for a particular material. The strength envelope is …

Members Only  

Comparing specs

April 1, 2009

GMA techline answers from Bob Koerner Subject: Comparing specs — I want to know how can I compare specification values of ASTM with ISO?? I sell products tested with ASTM methods, but some clients give me an ISO specification. I want to know which product fits their requirements. (Claudia, Mexico) Reply: You ask an excellent …

New ASTM standard for EPDM sheet material

February 1, 2009

A new ASTM standard developed by ASTM International Committee D35 on Geosynthetics fills a need for an internationally recognized standard to ensure that EPDM sheet material received by customers is consistent regardless of the manufacturer. The new standard, D7465, Specification for Ethylene Propylene Diene Terpolymer (EPDM) Sheet Used in Geomembrane Applications, is under the jurisdiction …

Members Only  

Break/yield strengths

October 1, 2008

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-textured. The table 2b shows yield strength > break …