ASTM D5820-95(2023)

Standard Practice for Pressurized Air Channel Evaluation of Dual-Seamed Geomembranes

SIGNIFICANCE AND USE
5.1 The increased use of geomembranes as barrier materials to restrict liquid or gas movement, and the common use of dual-track seams in joining these sheets, has created a need for a standard nondestructive test by which the quality of the seams can be assessed for continuity and watertightness. The test is not intended to provide any indication of the physical strength of the seam.  
5.2 This practice recommends an air pressure test within the channel created between dual-seamed tracks whereby the presence of unbonded sections or channels, voids, nonhomogenities, discontinuities, foreign objects, and the like, in the seamed region can be identified.  
5.3 This technique is intended for use on seams between geomembrane sheets formulated from the appropriate polymers and compounding ingredients to form a plastic or elastomer sheet material that meets all specified requirements for the end use of the product.
SCOPE
1.1 This practice covers a nondestructive evaluation of the continuity of parallel geomembrane seams separated by an unwelded air channel. The unwelded air channel between the two distinct seamed regions is sealed and inflated with air to a predetermined pressure. Long lengths of seam can be evaluated by this practice more quickly than by other common nondestructive tests.  
1.2 This practice should not be used as a substitute for destructive testing. Used in conjunction with destructive testing, this method can provide additional information regarding the seams undergoing testing.  
1.3 This practice supercedes Practice D4437/D4437M for geomembrane seams that include an air channel. Practice D4437/D4437M may continue to be used for other types of seams. The user is referred to the referenced standards or to EPA/530/SW-91/051 for additional information regarding geomembrane seaming techniques and construction quality assurance.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Oct-2023
• ICS: 59.080.70 - Geotextiles
• Technical Committee: D35 - Geosynthetics
• Drafting Committee: D35.10 - Geomembranes

Relations

• Replaces: ASTM D5820-95(2018) - Standard Practice for Pressurized Air Channel Evaluation of Dual-Seamed Geomembranes
• Effective Date: 01-Nov-2023
• Refers: ASTM D4439-24 - Standard Terminology for Geosynthetics
• Effective Date: 01-Feb-2024
• Refers: ASTM D4437/D4437M-16(2023) - Standard Practice for Nondestructive Testing (NDT) for Determining the Integrity of Seams Used in Joining Flexible Polymeric Sheet Geomembranes
• Effective Date: 01-Nov-2023
• Refers: ASTM D4437/D4437M-16(2018) - Standard Practice for Nondestructive Testing (NDT) for Determining the Integrity of Seams Used in Joining Flexible Polymeric Sheet Geomembranes
• Effective Date: 01-Feb-2018
• Referred By: ASTM D7240-18 - Standard Practice for Electrical Leak Location Using Geomembranes with an Insulating Layer in Intimate Contact with a Conductive Layer via Electrical Capacitance Technique (Conductive-Backed Geomembrane Spark Test)
• Effective Date: 01-Nov-2023
• Referred By: ASTM D8364/D8364M-21 - Standard Specification for Geosynthetic Cementitious Composite Mat (GCCM) Materials
• Effective Date: 01-Nov-2023
• Referred By: ASTM D8173-23 - Standard Guide for Site Preparation, Layout, Installation, and Hydration of Geosynthetic Cementitious Composite Mats
• Effective Date: 01-Nov-2023
• Referred By: ASTM D4439-23b - Standard Terminology for Geosynthetics
• Effective Date: 01-Nov-2023
• Referred By: ASTM D7700-22 - Standard Guide for Selecting Test Methods for Geomembrane Seams
• Effective Date: 01-Nov-2023

Overview

ASTM D5820-95(2023), Standard Practice for Pressurized Air Channel Evaluation of Dual-Seamed Geomembranes, specifies a nondestructive method for evaluating the integrity and continuity of dual-seamed geomembrane joints. With the increased deployment of geomembranes as critical barriers against liquid or gas migration in environmental and civil engineering applications, ensuring the watertightness of seams is essential. This standard describes a practice where a pressurized air channel, created between parallel welded seams, is used to detect discontinuities like unbonded areas, voids, or inclusions in the seam region.

The practice is intended for use on geomembrane sheets made from suitable polymers and materials, but does not assess seam strength. Instead, it serves as a rapid, effective quality assurance tool for large-scale projects such as landfills, containment ponds, or wastewater treatment facilities.

Key Topics

• Nondestructive Testing (NDT): Evaluates seam continuity without damaging the geomembrane.
• Dual-Seamed Geomembranes: Focuses on seams formed by two parallel welded zones separated by an unwelded air channel.
• Pressurized Air Channel: Air is injected into the unwelded channel, which is then monitored for pressure drops, indicating potential discontinuities or leaks.
• Test Procedure:
  • Seal ends of the air channel.
  • Connect a calibrated pressure gauge.
  • Inflate the channel to specified pressure for the geomembrane type.
  • Observe pressure drop over a recommended minimum of 2 minutes.
  • Validate the full seam length by releasing pressure from the end opposite the gauge.
• Result Reporting: Includes location, test conditions, initial and final pressure, pressure drop, outcome, and any remedial actions taken.

Applications

The pressurized air channel evaluation method is widely used across industries and projects where geomembrane seams play a vital role in environmental containment. Practical applications include:

• Landfill Liners and Caps: To prevent leachate and gas migration, ensuring regulatory compliance and environmental safety.
• Mining Operations: In tailings dams and heap leach pads, geomembrane seams must prevent hazardous fluid escape.
• Wastewater Treatment Facilities: For lining lagoons and containment ponds, ensuring asset longevity and safety.
• Water Reservoirs and Canals: To secure water storage and transport systems against seepage losses.
• Secondary Containment: Used in chemical storage and fuel handling installations.

This air channel testing method offers efficient coverage over long seam lengths, providing rapid quality checks compared with other nondestructive seam integrity tests.

Related Standards

Organizations and professionals using ASTM D5820 should also be familiar with relevant terms, alternate testing methods, and industry documentation, including:

• ASTM D4437/D4437M - Nondestructive Testing of Flexible Polymeric Sheet Geomembrane Seams (for seams without air channels).
• ASTM D4439 - Terminology for Geosynthetics.
• ASTM D4491/D4491M - Test Methods for Water Permeability of Geotextiles by Permittivity.
• EPA/530/SW-91/051 - Technical Guidance Document: Inspection Techniques for Fabrication of Geomembrane Field Seams.

Referencing these standards provides a comprehensive understanding of geomembrane testing, construction quality assurance, and terminology.

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Keywords: ASTM D5820, pressurized air channel test, dual-seamed geomembranes, nondestructive testing, geomembrane seam evaluation, geosynthetics, seam integrity, quality assurance, containment liner testing.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D5820 − 95 (Reapproved 2023)
Standard Practice for
Pressurized Air Channel Evaluation of Dual-Seamed
Geomembranes
This standard is issued under the fixed designation D5820; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 This practice covers a nondestructive evaluation of the
D4437/D4437M Practice for Nondestructive Testing (NDT)
continuity of parallel geomembrane seams separated by an
for Determining the Integrity of Seams Used in Joining
unwelded air channel. The unwelded air channel between the
Flexible Polymeric Sheet Geomembranes
two distinct seamed regions is sealed and inflated with air to a
D4439 Terminology for Geosynthetics
predetermined pressure. Long lengths of seam can be evaluated
D4491/D4491M Test Methods for Water Permeability of
by this practice more quickly than by other common nonde-
Geotextiles by Permittivity
structive tests.
2.2 EPA Standard:
1.2 This practice should not be used as a substitute for EPA/530/SW-91/051 Technical Guidance Document: In-
spection Techniques for the Fabrication of Geomembrane
destructive testing. Used in conjunction with destructive
Field Seams
testing, this method can provide additional information regard-
ing the seams undergoing testing.
3. Terminology
1.3 This practice supercedes Practice D4437/D4437M for
3.1 Definitions:
geomembrane seams that include an air channel. Practice
3.1.1 dual seam, n—a geomembrane seam with two parallel
D4437/D4437M may continue to be used for other types of
welded zones separated by an unwelded air space.
seams. The user is referred to the referenced standards or to
3.1.1.1 Discussion—The dual seam itself can be made by a
EPA/530/SW-91/051 for additional information regarding
number of methods, the most common being the hot wedge
geomembrane seaming techniques and construction quality
technique. Other possible methods include hot air and ultra-
assurance.
sonic bonding techniques.
1.4 This standard does not purport to address all of the 3.1.2 geomembrane, n—an essentially impermeable geosyn-
thetic composed of one or more synthetic sheets.
safety concerns, if any, associated with its use. It is the
3.1.2.1 Discussion—In geotechnical engineering, “imper-
responsibility of the user of this standard to establish appro-
meable” essentially means that no measurable liquid flows
priate safety, health, and environmental practices and deter-
through a geosynthetic when tested in accordance with Test
mine the applicability of regulatory limitations prior to use.
Methods D4491/D4491M.
1.5 This international standard was developed in accor-
3.1.3 seam, n—a permanent joining of two or more materi-
dance with internationally recognized principles on standard-
als.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
3.2 For definitions of other terms, see Terminology D4439.
mendations issued by the World Trade Organization Technical
4. Summary of Practice
Barriers to Trade (TBT) Committee.
4.1 This practice utilizes a dual seam where an air channel
exists between the two welded zones. Both ends of the air
channel are sealed and then a pressure gauge is attached to the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
This practice is under the jurisdiction of ASTM Committee D35 on Geosyn- contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
thetics and is the direct responsibility of Subcommittee D35.10 on Geomembranes. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Nov. 1, 2023. Published November 2023. Originally the ASTM website.
approved in 1995. Last previous edition approved in 2018 as D5820 – 95 (2018). Available from the Superintendent of Documents, U.S. Government Printing
DOI: 10.1520/D5820-95R23. Office, Washington, DC 20402.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5820 − 95 (2023)
air space. Air pressure is applied and the gauge is monitored for 7. Procedure
excessive gauge air pressure drop.
7.1 After the dual-track seam is fabricated and the length of
seam that is to be evaluated is determined, seal off the two ends
4.2 Air pressures used in this practice are related to the
of the continuous air channel.
thickness, stiffness, and material type of the geomembrane.
7.2 Connect the pressure gauge directly to the air channel.
4.3 The minimum monitoring time is recommended to be
2 min following stabilization of the pressure.
7.3 Connect an air pump to the pressure gauge with a
flexible hose via a quick connect and pressurize the air channel
4.4 Maximum allowable loss of air pressure varies depend-
to the pressure appropriate for the geomembrane type.
ing upon thickness, stiffness, and type of material of the
geomembrane.
7.4 Remove the flexible hose that connects the air channel
to the pressure gauge. Following pressure stabilization, observe
5. Significance and Use
the air pressure gauge for the desired test time. The test time
should be a minimum of 2 min. Mark the time and pressure of
5.1 The increased use of geomembranes as barrier materials
the beginning and end of the test on the geomembrane with a
to restrict liquid or gas movement, and the common use of
visible marker. The maximum allowable pressure drop may be
dual-track seams in joining these sheets, has created a ne
...