ASTM D7749/D7749M-11(2023)e1
(Test Method)Standard Test Method for Determining Integrity of Seams Produced Using Thermo-Fusion Methods for Reinforced Geomembranes by the Grab Method
Standard Test Method for Determining Integrity of Seams Produced Using Thermo-Fusion Methods for Reinforced Geomembranes by the Grab Method
SIGNIFICANCE AND USE
4.1 The use of reinforced geomembranes as barrier materials has created a need for a standard test method to evaluate the quality of seams produced by thermo-fusion methods. This test method is used for quality control purposes and is intended to provide quality control and quality assurance personnel with data to evaluate seam quality.
4.2 Values obtained with this method can be correlated to Test Method D7004/D7004M. The purpose of correlating these methods was for the strength of parent material measured in Test Method D7004/D7004M to be comparable to seam strength measured by the test outlined here. The value obtained with this method cannot be compared to values for strip method, Test Method D7003/D7003M, for parent material or Test Method D7747/D7747M, strip method for reinforced seams.
SCOPE
1.1 This test method describes destructive quality control tests used to determine the integrity of thermo-fusion seams made with reinforced geomembranes. A test procedure is described that uses seam tests using grab specimens for seam shear strength.
1.2 The types of thermal field and factory seaming techniques used to construct geomembrane seams include the following:
1.2.1 Hot Air—This technique introduces high-temperature air between two geomembrane surfaces to facilitate melting. Pressure is applied to the top or bottom geomembrane, forcing together the two surfaces to form a continuous bond.
1.2.2 Hot Wedge—This technique melts the two geomembrane surfaces to be seamed by running a hot metal wedge between them. Pressure is applied to the top and bottom geomembrane to form a continuous bond. Some seams of this kind are made with dual tracks separated by a non-bonded gap. These seams are sometimes referred to as dual hot wedge seams or double-track seams.
1.2.3 Extrusion—This technique encompasses extruding molten resin between two geomembranes or at the edge of two overlapped geomembranes to effect a continuous bond.
1.2.4 Radio Frequency (RF) or Dielectric—High-frequency dielectric equipment is used to generate heat and pressure to form an overlap seam in factory fabrication.
1.2.5 Impulse—Clamping bars heated by wires or a ribbon melt the sheets clamped between them. A cooling period while still clamped allows the polymer to solidify before being released.
1.3 The types of materials covered by this test method include, but are not limited to, reinforced geomembranes made from the following polymers:
1.3.1 Very low-density polyethylene (VLDPE).
1.3.2 Linear low-density polyethylene (LLDPE).
1.3.3 Flexible polypropylene (fPP).
1.3.4 Polyvinyl chloride (PVC).
1.3.5 Chlorosulfonated polyethylene (CSPE).
1.3.6 Ethylene interpolymer alloy (EIA).
1.4 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.
1.5 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.
1.6 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
Relations
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.
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Designation: D7749/D7749M − 11 (Reapproved 2023)
Standard Test Method for
Determining Integrity of Seams Produced Using Thermo-
Fusion Methods for Reinforced Geomembranes by the Grab
Method
This standard is issued under the fixed designation D7749/D7749M; 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.
ε NOTE—Designation and units information were editorially updated in November 2023.
1. Scope 1.3.1 Very low-density polyethylene (VLDPE).
1.3.2 Linear low-density polyethylene (LLDPE).
1.1 This test method describes destructive quality control
1.3.3 Flexible polypropylene (fPP).
tests used to determine the integrity of thermo-fusion seams
1.3.4 Polyvinyl chloride (PVC).
made with reinforced geomembranes. A test procedure is
1.3.5 Chlorosulfonated polyethylene (CSPE).
described that uses seam tests using grab specimens for seam
1.3.6 Ethylene interpolymer alloy (EIA).
shear strength.
1.4 Units—The values stated in either SI units or inch-
1.2 The types of thermal field and factory seaming tech-
pound units are to be regarded separately as standard. The
niques used to construct geomembrane seams include the
values stated in each system may not be exact equivalents;
following:
therefore, each system shall be used independently of the other.
1.2.1 Hot Air—This technique introduces high-temperature
Combining values from the two systems may result in noncon-
air between two geomembrane surfaces to facilitate melting.
formance with the standard.
Pressure is applied to the top or bottom geomembrane, forcing
together the two surfaces to form a continuous bond. 1.5 This standard does not purport to address all of the
1.2.2 Hot Wedge—This technique melts the two geomem- safety concerns, if any, associated with its use. It is the
brane surfaces to be seamed by running a hot metal wedge
responsibility of the user of this standard to establish appro-
between them. Pressure is applied to the top and bottom priate safety, health, and environmental practices and deter-
geomembrane to form a continuous bond. Some seams of this
mine the applicability of regulatory limitations prior to use.
kind are made with dual tracks separated by a non-bonded gap. 1.6 This international standard was developed in accor-
These seams are sometimes referred to as dual hot wedge dance with internationally recognized principles on standard-
seams or double-track seams. ization established in the Decision on Principles for the
1.2.3 Extrusion—This technique encompasses extruding Development of International Standards, Guides and Recom-
molten resin between two geomembranes or at the edge of two mendations issued by the World Trade Organization Technical
overlapped geomembranes to effect a continuous bond. Barriers to Trade (TBT) Committee.
1.2.4 Radio Frequency (RF) or Dielectric—High-frequency
2. Referenced Documents
dielectric equipment is used to generate heat and pressure to
form an overlap seam in factory fabrication.
2.1 ASTM Standards:
1.2.5 Impulse—Clamping bars heated by wires or a ribbon
D76/D76M Specification for Tensile Testing Machines for
melt the sheets clamped between them. A cooling period while
Textiles
still clamped allows the polymer to solidify before being
D4439 Terminology for Geosynthetics
released.
D7003/D7003M Test Method for Strip Tensile Properties of
Reinforced Geomembranes
1.3 The types of materials covered by this test method
D7004/D7004M Test Method for Grab Tensile Properties of
include, but are not limited to, reinforced geomembranes made
Reinforced Geomembranes
from the following polymers:
D7747/D7747M Test Method for Determining Integrity of
This test method is under the jurisdiction of ASTM Committee D35 on
Geosynthetics and is the direct responsibility of Subcommittee D35.10 on Geomem-
branes. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2023. Published November 2023. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 2011. Last previous edition approved in 2018 as D7749 – 11 (2018). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/D7749_D7749M-11R23E01. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D7749/D7749M − 11 (2023)
Seams Produced Using Thermo-Fusion Methods for Re-
inforced Geomembranes by the Strip Tensile Method
3. Terminology
3.1 Definitions—Refer to Terminology D4439 for defini-
tions of terms applying to this test method.
4. Significance and Use
4.1 The use of reinforced geomembranes as barrier materi-
als has created a need for a standard test method to evaluate the
quality of seams produced by thermo-fusion methods. This test
method is used for quality control purposes and is intended to
provide quality control and quality assurance personnel with
data to evaluate seam quality.
4.2 Values obtained with this method can be correlated to
Test Method D7004/D7004M. The purpose of correlating these
methods was for the strength of parent material measured in
Test Method D7004/D7004M to be comparable to seam
strength measured by the test outlined here. The value obtained
with this method cannot be compared to values for strip
method, Test Method D7003/D7003M, for parent material or
Test Method D7747/D7747M, strip method for reinforced
seams.
5. Apparatus
5.1 Tensile Testing Machine—Constant rate of extension
(CRE) equipm
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