1. Stress Cracking of Geomembranes and Geopipe - In addition to Grace Hsuan’s ongoing evaluations of HDPE geomembranes, she is presently focusing on HDPE drainage and duct pipe mainly for the Florida DOT. The goal for both geomembranes and geopipe is to include technically viable test methods and limiting values for inclusion in generic specifications. 
  2. Durability of Polypropylene Geotextile Fibers - Incubation at temperatures of 75, 65 and 55°C in high oxygen pressure containers is ongoing using PP-woven geotextile fibers. This study periodically measures changes in density, dimensions, mass, morphology, strength, elongation, modulus, melt index, OIT and carbonyl content. Dr. Hsuan is in charge of the project.
  3. In-Situ Temperature Monitoring of Liner and Cover Geomembranes in Dry and Wet Landfills - Dr. George Koerner is measuring the in-situ temperature behavior of liner and cover geomembranes and has installed 60± thermocouples for long term measurements in both wet and dry municipal solid waste landfills in Pennsylvania. The project has been updated into its 14th-year and has been presented at the Global Waste Conference in September, 2008. 
  4. Bioreactor (aka, Wet) Landfill Behavior and Properties - One of the landfill cells mentioned in Item 3 is at field capacity, hence it is a true anaerobic bioreactor. Dr. George Koerner is in charge of considerable monitoring at this cell which includes the following

Data is being collected on a monthly basis. The timeline of the project calls for monitoring for 5 to 10 years. This activity will now extend to an adjacent landfill to see how reproducible the data is with a slightly different waste mass. It was also presented at the Global Waste Conference in September.

  1. Flow Behavior of Fully Degraded Waste - A field project under sponsorship of GSI and Waste Management investigates the drainage of highly degraded MSW placed directly on leachate collection systems. The leachate collection systems consist of both natural soils and geosynthetic drains. The project is now in its third year and is at a landfill in the Philadelphia area. We gave our third paper on the topic at the Global Waste Conference in September.
  2. Hydrostatic Creep Puncture of Geomembranes - This ten-year creep puncture project has just been dismantled and an analysis of the findings has been concluded. A short version is available as GSI White Paper #14 on our website and a complete paper has been submitted to the Journal of Geotextiles and Geomembranes for review and possible publication. Contact us if you are interested in the draft paper. 
  3. UV Exposure of Geomembranes - GSI is using UV-fluorescent devices to evaluate the projected exposed lifetime of many different types of geomembranes. Presently being incubated are HDPE, LLDPE, 5 fPPs, PVC, EPDM and PE-R. Exposure times of 40,000 light hours are now realized at 70°C and a replicate set of samples are now being incubated at 60°C.  These will take at least 60,000 light hours (> 8-years).  The third sequence will be at 80°C. 
  4. UV Exposure of Geogrids - The UV-fluorescent exposure of four different biaxial geogrids which are used at the exposed surfaces of welded wire mesh retaining walls is ongoing. The geogrids are now up to 18,000 light hours and data is being generated and sent to the respective manufacturers.  As with the geomembranes, replicate samples will now be incubated at 60°C for eventual use in Arrhenius Modeling and lifetime prediction.  The last set will be at 80°C.
  5. UV Exposure of TRM Fibers - We are also using UV-fluorescent exposure of several turf reinforcement mat fibers to assess their lifetime capabilities. Contact Bob Koerner if you have materials for inclusion into this effort.
  6. UV Exposure of Repair Tape - We have found that a particular type of polyethylene repair tape has been successfully used to repair an exposed geomembrane at a Delaware landfill. After five-years it appears very durable. Original samples are being evaluated in one of our fluorescent tube weatherometers per ASTM D7238 at 70°C.
  7. Geomembrane Chalking - With the reinstatement of the flexible polypropylene geomembrane specification, i.e., GRI-GM18, we are in need of a test method to assess the degree of geomembrane caulking.  This type of degradation has been experienced on several exposed geomembrane sites and on laboratory weatherometers samples while being incubated.
  8. Geomembrane Flaking - In addition to possible cracking and chalking of flexible polypropylene geomembranes, our first instance of thin flakes being removed from the geomembrane’s surface is being investigated.  More later.
  9. Generic Specifications - A major effort is ongoing with respect to the development and maintenance of generic geosynthetic specifications. The current status of these specifications is as follows:

Completed and Regularly Updated

GM13 - HDPE Geomembranes
GM17 - LLDPE Geomembranes
GM21 - EPDM Geomembranes
GM22 - Exposed Temporary Covers
GM19 - Geomembrane Seams
GT10 - Geotextile Tubes
GT12 - Geotextile Cushions (ASTM & ISO)
GT13 - Geotextile Separators (ASTM & ISO)
GCL3 - Geosynthetic Clay Liners

Working Within Focus Groups

GCXX - TRMs for Erosion Control
GTXX - High Strength Reinforcement Geotextiles
GMX – LLDPE-R Geomembranes

Delayed or Off in the Distance

GGXX - Bidirectional Geogrids
GGXX - Unidirectional Geogrids
GNXX - Geonet Drainage Composites
GCXX - Drainage Geocomposites

The complete specifications are available to everyone (members and nonmembers) on the open section of our Home Page. Please download and use them accordingly. Also note that this is where the latest modification will always be available.