ASTM D7747-11
(Test Method)Standard Test Method for Determining Integrity of Seams Produced Using Thermo-Fusion Methods for Reinforced Geomembranes by the Strip Tensile Method
Standard Test Method for Determining Integrity of Seams Produced Using Thermo-Fusion Methods for Reinforced Geomembranes by the Strip Tensile Method
SIGNIFICANCE AND USE
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.
This standard arose from the need for a destructive test method for evaluating seams of reinforced geomembranes. Standards written for destructive testing of nonreinforced geomembranes do not include all Break Codes (figure 4) applicable to reinforced geomembranes.
When reinforcement occurs in directions other than machine and cross machine, scrim are cut at specimen edges, generally lowering results. To partially compensate for this, testing can be performed according to , or the 2 in. wide strip specimen specified in this method can be utilized. Testing of 1 in. and 2 in. specimens is Method A and method B respectively.
The shear test outlined in this method correlates to strength of parent material measured according to ASTM only if reinforcement is parallel to TD. For other materials, seam strength and parent material strength can be compared through and . Values obtained with the strip methods shall not be compared to values obtained with grab methods.
SCOPE
1.1 This test method describes destructive quality control tests used to determine the integrity of thermo-fusion seams made with reinforced geomembranes. Test procedures are described for seam tests for peel and shear properties using strip specimens.
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 Air—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 melts 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 non-conformance 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 and health practices and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
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Designation:D7747 −11
StandardTest Method for
Determining Integrity of Seams Produced Using Thermo-
Fusion Methods for Reinforced Geomembranes by the Strip
Tensile Method
This standard is issued under the fixed designation D7747; 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 1.3.3 Flexible Polypropylene (fPP).
1.3.4 Polyvinyl Chloride (PVC).
1.1 This test method describes destructive quality control
1.3.5 Chlorosulfonated polyethylene (CSPE).
tests used to determine the integrity of thermo-fusion seams
1.3.6 Ethylene Interpolymer Alloy (EIA).
made with reinforced geomembranes. Test procedures are
described for seam tests for peel and shear properties using 1.4 Units—The values stated in either SI units or inch-
strip specimens. pound units are to be regarded separately as standard. The
values stated in each system may not be exact equivalents;
1.2 The types of thermal field and factory seaming tech-
therefore,eachsystemshallbeusedindependentlyoftheother.
niques used to construct geomembrane seams include the
Combining values from the two systems may result in non-
following.
conformance with the standard.
1.2.1 Hot Air—This technique introduces high-temperature
1.5 This standard does not purport to address all of the
air between two geomembrane surfaces to facilitate melting.
safety concerns, if any, associated with its use. It is the
Pressure is applied to the top or bottom geomembrane, forcing
responsibility of the user of this standard to establish appro-
together the two surfaces to form a continuous bond.
priate safety and health practices and determine the applica-
1.2.2 Hot Air—This technique melts the two geomembrane
bility of regulatory limitations prior to use.
surfaces to be seamed by running a hot metal wedge between
them. Pressure is applied to the top and bottom geomembrane
2. Referenced Documents
to form a continuous bond. Some seams of this kind are made
with dual tracks separated by a non-bonded gap. These seams 2.1 ASTM Standards:
D4439 Terminology for Geosynthetics
are sometimes referred to as dual hot wedge seams or double-
track seams. D7003 Test Method for Strip Tensile Properties of Rein-
1.2.3 Extrusion—This technique encompasses extruding forced Geomembranes
molten resin between two geomembranes or at the edge of two D7004 Test Method for Grab Tensile Properties of Rein-
overlapped geomembranes to effect a continuous bond. forced Geomembranes
1.2.4 Radio Frequency (RF) or Dielectric—High frequency D76 Specification for Tensile Testing Machines for Textiles
dielectric equipment is used to generate heat and pressure to D7749 Test Method for Determining Integrity of Seams
form an overlap seam in factory fabrication. Produced Using Thermo-Fusion Methods for Reinforced
1.2.5 Impulse—Clamping bars heated by wires or a ribbon Geomembranes by the Grab Method
meltsthesheetsclampedbetweenthem.Acoolingperiodwhile
3. Terminology
still clamped allows the polymer to solidify before being
released. 3.1 Definitions—Refer to Terminology for Geosynthetics,
for definitions of terms applying to this test method.
1.3 The types of materials covered by this test method
include, but are not limited to, reinforced geomembranes made
4. Significance and Use
from the following polymers.
4.1 The use of reinforced geomembranes as barrier materi-
1.3.1 Very Low Density Polyethylene (VLDPE).
alshascreatedaneedforastandardtestmethodtoevaluatethe
1.3.2 Linear Low Density Polyethylene (LLDPE).
quality of seams produced by thermo-fusion methods.This test
This test method is under the jurisdiction of ASTM Committee D35 on
GeosyntheticsandisthedirectresponsibilityofSubcommitteeD35.10onGeomem- For referenced ASTM standards, visit the ASTM website, www.astm.org, or
branes. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved Oct. 1, 2011. Published October 2011. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
D7747–11. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7747−11
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 This standard arose from the need for a destructive test
method for evaluating seams of reinforced geomembranes.
Standards written for destructive testing of nonreinforced
geomembranes do not include all Break Codes (figure 4)
applicable to reinforced geomembranes.
4.3 When reinforcement occurs in directions other than
machine and cross machine, scrim are cut at specimen edges,
generally lowering results. To partially compensate for this,
testing can be performed according to D7749, or the 2 in. wide
strip specimen specified in this method can be utilized. Testing
of 1 in. and 2 in. specimens is Method A and method B
respectively.
4.4 The shear test outlined in this method correlates to
strength of parent material measured according to ASTM
D7003 only if reinforcement is parallel to TD. For other
FIG. 1Specimen configuration of seam sample.
materials, seam strength and parent material strength can be
compared through D7749 and D7004.Values obtained with the
strip methods shall not be compared to values obtained with
required to reach temperature equilibrium may vary according
grab methods.
to the material type and thickness.
5. Apparatus
7.2 Test Conditions—Conduct tests at the standard atmo-
sphere for testing geosynthetics, a temperature of 21+2°C
5.1 Tensile Testing Machine—Constant Rate of Extension
(7064°F) and a relative humidity between 50% to 70%, unless
(CRE) equipment meeting the requirements of ASTM D76.
otherwise specified.
The load cell shall be accurate
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