The GMA Techline

February 1st, 2020

Moderated by George R. Koerner and Y. “Grace” Hsuan DARCIAN PERMEABILITY Q: I am aware of the section in your book regarding geomembrane “permeability” and get from it that it aims to calculate an equivalent Darcian permeability using vapor diffusion via Fick’s law. Can one use the derived permeability then when calculating flow using Darcy’s […]

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Erosion control using concrete-enhanced synthetic turf

February 1st, 2020

By Bradford H. Cooley and Bryan Scholl Concrete-enhanced synthetic turf (CEST) is a hardened revetment system best described as a fiber-reinforced, flexible concrete liner. It consists of a high-friction, impermeable geomembrane layer overlain by an engineered synthetic turf, which is infilled with a 5,000 psi (3.45 × 107 Pa) high-strength cementitious mix. The turf fibers […]

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Lessons learned in alternative coal ash pond closure design and construction

October 1st, 2019

By Anna M. Saindon Coal ash pond closures often face unique challenges due to location, available borrow soils and construction constraints. These challenges can lead to alternative methods of closure to comply with Resource Conservation and Recovery Act (RCRA) Subtitle D and coal combustion residuals (CCR) regulations. This article summarizes the construction of the first […]

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Fabricated Geomembrane Institute (FGI) updates PVC geomembrane specification

September 30th, 2019

The Fabricated Geomembrane Institute (FGI) updated its Material Specification for New PVC Geomembranes, previously referred to as PGI 1104 and FGI 1117.  The new specification, FGI 9119, addresses camber or layflat, film gloss, shore hardness, and color deviation within a manufactured lot. The new specification introduces the FGI circumference test which measures the roll circumference […]

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Large-scale studies to evaluate the resilient modulus of geocell-reinforced pavement

April 1st, 2019

The 2017 ASCE report card (ASCE 2017) on civil infrastructure assigned grade “D” for America’s roads, and this rating necessitates the adoption of more sustainable and resilient approaches in design and construction of transport infrastructures such as highway embankments and pavements. Reclaimed asphalt pavement (RAP) material has been considered as one of the sustainable options […]

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The GMA Techline

April 1st, 2019

Vegetation causing gases under geomembrane? Q: I have a site where we are installing a high-density polyethylene (HDPE) liner in an existing pond. Because of some residual heavy metals in the top layer of soil, I would like to strip off the top 3–6 inches (7.6–15.2 cm) of soil and vegetation. Alternatively, we could mow and […]

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Plastatech unveils line of prefabricated geomembrane accessories

March 26th, 2019

Plastatech Engineering launched a new line of prefabricated accessories, featuring product styles such as a straight pipe boot, angled pipe boot, inside corner, outside corner and other customizable options. Designed to provide time-saving solutions for a variety of geomembrane projects, accessories are available in polyvinyl chloride (PVC), high-density polyethylene (HDPE), reinforced polyethylene (RPE), linear low-density […]

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Solmax introduces RockArmour geomembrane for oil and gas pipeline protection

March 25th, 2019

Solmax has partnered with Rock Armour LLC to introduce an innovative rockshield pipeline protection offering to the oil and gas industry. RockArmour is a conductive geomembrane material designed to shield pipelines from rock impact damage during backfilling and problems caused by land movement after pipeline installation. “Solmax has a long-standing relationship with Rock Armour LLC and we […]

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A leachate pond geomembrane after 25 years of service

February 1st, 2019

This article reports on the evaluation of an exposed geomembrane liner in a landfill leachate pond after being in service for 25 years. The evaluation was performed in two campaigns: in August 2014 and in May 2018. The purpose of the evaluation was to determine the condition of the geomembrane and to provide a recommendation […]

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Layfield launches gas barrier geomembrane

January 14th, 2019

Layfield Geosynthetics announced the release of VaporFlex® Premium geomembrane. VaporFlex® Premium is a 7-layer coextruded geomembrane barrier with an ethylene vinyl alcohol (EVOH) core layer. This high-performance geomembrane is specifically designed to provide an ultra-low permeability gas barrier in a broad range of geoenvironmental applications. When compared to high-density polyethylene (HDPE), the VaporFlex® Premium was […]

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