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The ASTM Committee D35 on Geosynthetics conducted its 2016 winter meeting in San Antonio, Texas, Jan. 27–29, 2016. The first order of business was the installation of new officers and members-at-large:
James Goddard, Committee D35 chairman
Eli Cuelho, 1st vice-chairman
Jimmy Youngblood, 2nd vice-chairman
Gary Torosian, secretary
Mark Wayne, membership chairman
Tim Bauters, membership-at-large
Richard Bledsoe, membership-at-large
Melissa Medlin, membership-at-large
Mark Wolschon, membership-at-large
Aigen Zhao, membership-at-large
Congratulations to the new officers and members-at-large.
Report from D35.02 Subcommittee on Endurance Properties–Eric Blond, chairman
The industry is turning to more specialized products with functionalized layers such as white, conductive, or gas barriers. Testing these multicomponent geomembranes is currently being investigated in D35.02, in particular for properties affecting the durability and polymer properties of these products such as density (D792), specific gravity (D1505), oxidative induction time (D3895), and carbon black content (D1603 and D4218).
These are currently hosted by D20 on plastics and will be imported into D35 for better adaptation to geomembrane structures and formulations. Other properties under revision in this effort include HP-OIT (D5885), carbon black dispersion (D5596), and stress crack resistance (D5397).
During the last meeting, D35.02 also initiated efforts to upgrade chemical immersion standards replacing the old EPA9090. All of these standards will be reviewed to reflect state-of-the-art testing practices and polymer science: D5747 on geomembranes, D6213 on geogrids (to include the evaluation of PVA geogrids and cover polyester reinforcement geotextiles as well), D6388 on geonets, D6389 on geotextiles. ASTM members and standard users are invited to provide comments and suggestions to the group to contribute to this effort.
Report from D35.03 Subcommittee on Permeability and Filtration–David Suits, chairman
In addition to the regular meetings of existing task groups at the D35.03 meeting in San Antonio, three new task groups have been formed. The first task group will be working on developing a standard for transmissivity testing of drain tube geocomposites. The second task group comes as a result of a request coming out of the D35 meeting in India in December and will be developing a standard for testing the abrasion of geotextile tubes water laden with various sediments. The third task group will be developing a specification for specific geopipes. All three groups will meet at the June 29–July 1, 2016, ASTM meetings in Chicago.
Report from D35.04 Subcommittee on Geosynthetic Clay Liners–Kent von Maubeuge, chairman
The D35.04 subcommittee continued work on multicomponent GCLs to incorporate them into active standards. For example, ASTM D5888 “Standard Practice for Quality Control of Geosynthetic Clay Liners” was modified and test procedures as well as recommended test frequencies are now being added for multicomponent GCLs.
The ASTM D5891 “Fluid Loss Index Test for Bentonite” standard was discussed in detail to improve the precision of the tests among labs. It was identified that the filter paper might have an influence on the test values. A follow-up round-robin test should clarify this issue.
The hydraulic properties of GCLs are covered in two standards (D5889 and D6766) and both are under revision. The main topics of discussion are the adjustment to the CEN EN standard 16416, where the reporting temperature is 10 C, rather than 20 C as stated in the ASTM standard. Further discussions in these standards are the measuring method of the GCL thickness that will be discussed during upcoming meetings.
A new working item that should lead to a standard is the site conditions for a test pad to evaluate the installation stresses on a GCL in a covered and uncovered situation. A second draft was presented and the discussions will be incorporated into the next working document.
In the next ASTM meetings June 29–July 1, presentations on polymer testing of polymer-treated bentonites will be presented and discussed whether any specific test standards are needed.
Report from D35.05 Subcommittee on Geosynthetics in Erosion and Sediment Control–Joel Sprague, chairman
Work continues on the most commonly used rolled erosion control product (RECP) index tests: D6525 on thickness, D6566 on mass/area, D6818 on tensile strength, and D6567 on light penetration. All of these standards received persuasive negatives on a recent ballot that will require additional changes and clarifications to the procedures. Clarification of the apparatus details and testing procedures used in conducting both light penetration and stiffness (D6575) testing is ongoing.
D6454 on turf reinforcement mat (TRM) compression was reapproved, but D6524 on TRM resiliency has some needed changes based on a recent ballot.
Work on standards for geosynthetic cementitious composite mats (GCCM) continues, including development of a flexural strength test method and an installation guide. A new standard, D8030/D8030M “Standard Practice for Sample Preparation for GCCMs,” was approved.
After reviewing both Erosion Control Technology Council (ECTC) and Geosynthetic Institute (GSI) specifications for TRMs, it was decided that a more user-friendly specification was needed and should be developed within D35.05. A proposed test method for horizontal permeability of sediment retention devices (SRDs) received one negative from a recent ballot that suggested some helpful improvements that will be added to the proposed standard. Further work will be initiated on a test method to quantify the “functional longevity” of RECPs and SRDs.
Report on D35.10 Subcommittee on Geomembranes–Gary Kolbasuk, chairman
Because this subcommittee’s standards are up to date and achieved approval of all recent ballot items, the subcommittee did not meet.
Bob Mackey is the immediate past-chairman of ASTM Committee D35 on Geosynthetics and is a member of the Editorial Advisory Committee for Geosynthetics magazine.