Impregnation of GCLs

April 1, 2022  |  Q&A: GMA Techline

Q: We are confused with the term “impregnation” as it relates to seaming geosynthetic clay liners (GCLs). There are two types of impregnations: (1) Edge impregnation, and (2) complete nonwoven (cap layer) impregnation of GCLs. How does a manufacturer do this?
Read More
GCL-GM geocomposite: Which end is up?

April 1, 2022  |  Q&A: GMA Techline

Q: In a geosynthetic clay liner-geomembrane (GCL-GM) geocomposite, does it make any difference which side of the geocomposite is up: GM or clay?
Read More
Calendared nonwoven geotextiles

April 1, 2022  |  Q&A: GMA Techline

Q: What is the difference between normal nonwoven and calendared nonwoven (both needlepunched) geotextiles? Where can we use calendared nonwoven geotextiles?
Read More
LCC curing effect on geogrids

April 1, 2022  |  Q&A: GMA Techline

Q: Can you tell me whether modest warming of geogrids (e.g., due to heat generated by the curing of lightweight cellular concrete [LCC]) might impact the long-term strength or long-term modulus of geogrids?
Read More
High pH effects geogrids?

April 1, 2022  |  Q&A: GMA Techline

Q: Can you tell me whether the high pH of curing portland cement (typically ~12.4) might have any impact on the long-term performance of geogrids?
Read More
Methane gas geomembrane permeability

April 1, 2022  |  Q&A: GMA Techline

Q: What is the least permeable geomembrane to methane gas? Regarding the permeability of geomembranes to methane gas, could you send me some technical guidelines?
Read More
Scratch impact on HDPE liners

April 1, 2022  |  Q&A: GMA Techline

Q: I have a project where multiple and extensive scratches were created on the high-density polyethylene (HDPE) liner for a reservoir due to poor construction practices. (See the following Figures 2–4.)
Read More
Sand fines overlying geocomposite

April 1, 2022  |  Q&A: GMA Techline

Q: We are working at a site with a permitted landfill cell with a leachate collection system that includes a drainage geocomposite with 12 inches (305 mm) of leachate collection sand overlying it. My question has to do with the percentage of fines in sand on a geocomposite. Our leachate collection p…
Read More
Members Only  
Geosynthetics and sustainability: How is our industry doing?

April 1, 2022  |  Features

Sustainability is a complex issue, but there are some very simple and direct truths about it. The world’s population is nearly 8 billion people; while the population growth rate has slowed in recent years, the earth’s population continues to rise. There are simply not sufficient resources to pro…
Read More
Members Only  
Complex geosynthetic liner system for the 70 Ranch Raw Water Reservoir

April 1, 2022  |  Features

Irrigation water in the western United States has always been a major concern for farming and ranching, especially in drought years. Water can be both scarce and expensive, and planning for future water storage and accessibility based on projected use is of paramount importance for irrigation distri…
Read More