ASTM D6768-04(2009)
(Test Method)Standard Test Method for Tensile Strength of Geosynthetic Clay Liners
Standard Test Method for Tensile Strength of Geosynthetic Clay Liners
SIGNIFICANCE AND USE
This test method may be used for the acceptance testing of commercial shipments of GCLs but caution is advised since information about between-laboratory precision is incomplete. Comparative tests as directed in 5.1.1 may be advisable.
In cases of a dispute arising from differences in reported test results when using this test method for acceptance of shipments, the purchaser and the supplier should conduct comparative tests to determine if there is a statistical bias. The two parties should take a group of test samples that are as homogeneous as possible and which are from the lot of material in question.
Some modification of clamping techniques may be necessary for a given GCL depending upon its structure. Specimen clamping may be modified as required at the discretion of the individual laboratory providing a representative tensile strength is obtained. In any event, the procedure described in Section 10 of this test method for obtaining tensile strength must be maintained.
This test method is applicable for testing GCLs as received. It is used with a constant rate of extension type tension apparatus.
SCOPE
1.1 The test method establishes the procedures for the measurement of tensile strength of Geosynthetic Clay Liner (GCL). This test method is strictly an index test method to be used to verify the tensile strength of GCLs. Results from this test method should not be considered as an indication of actual or long-term performance of the geosynthetic(s) in field applications.
1.2 The values in SI units are to be regarded as the standard. Values in pound units are in parentheses for information.
1.3 This standard may involve hazardous materials, operations, and equipment. 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)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D6768 − 04(Reapproved 2009)
Standard Test Method for
Tensile Strength of Geosynthetic Clay Liners
This standard is issued under the fixed designation D6768; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope other geotechnical engineering related material as an integral
part of a project, structure, or system. D4439
1.1 The test method establishes the procedures for the
3.2 geosynthetic clay liner, n—a manufactured hydraulic
measurement of tensile strength of Geosynthetic Clay Liner
barrier consisting of clay bonded to a layer or layers of
(GCL). This test method is strictly an index test method to be
geosynthetic material(s).
used to verify the tensile strength of GCLs. Results from this
testmethodshouldnotbeconsideredasanindicationofactual
3.3 For terminology of other terms used in this test method,
or long-term performance of the geosynthetic(s) in field
refer to Terminologies D123 and D4439.
applications.
4. Summary of Test Method
1.2 ThevaluesinSIunitsaretoberegardedasthestandard.
4.1 A 100 mm (4-in). wide specimen is gripped across its
Values in pound units are in parentheses for information.
entirewidthintheclampsofaconstantrateofextension(CRE)
1.3 This standard may involve hazardous materials,
type tensile testing machine operated at a prescribed rate of
operations, and equipment. This standard does not purport to
extension, applying a longitudinal force to the specimen until
address all of the safety concerns, if any, associated with its
the specimen ruptures.
use. It is the responsibility of the user of this standard to
establish appropriate safety and health practices and deter-
5. Significance and Use
mine the applicability of regulatory limitations prior to use.
5.1 Thistestmethodmaybeusedfortheacceptancetesting
of commercial shipments of GCLs but caution is advised since
2. Referenced Documents
information about between-laboratory precision is incomplete.
2.1 ASTM Standards:
Comparative tests as directed in 5.1.1 may be advisable.
D76Specification for Tensile Testing Machines for Textiles
5.1.1 In cases of a dispute arising from differences in
D123Terminology Relating to Textiles
reportedtestresultswhenusingthistestmethodforacceptance
D2905Practice for Statements on Number of Specimens for
of shipments, the purchaser and the supplier should conduct
Textiles (Withdrawn 2008)
comparative tests to determine if there is a statistical bias. The
D4439Terminology for Geosynthetics
two parties should take a group of test samples that are as
D5889Practice for Quality Control of Geosynthetic Clay
homogeneous as possible and which are from the lot of
Liners
material in question.
D6072PracticeforObtainingSamplesofGeosyntheticClay
5.2 Some modification of clamping techniques may be
Liners
necessary for a given GCL depending upon its structure.
3. Terminology
Specimen clamping may be modified as required at the
discretion of the individual laboratory providing a representa-
3.1 geosynthetic, n—a product manufactured wholly or in
tive tensile strength is obtained. In any event, the procedure
part from polymeric material used with soil, rock, earth, or
describedinSection10ofthistestmethodforobtainingtensile
strength must be maintained.
This test method is under the jurisdiction of ASTM Committee D35 on
5.3 This test method is applicable for testing GCLs as
Geosynthetics and is the direct responsibility of Subcommittee D35.04 on Geosyn-
thetic Clay Liners.
received. It is used with a constant rate of extension type
Current edition approved Nov. 1, 2009. Published January 2010. Originally
tension apparatus.
approved in 2002. Last previous edition approved in 2004 as D6768–04 DOI:
10.1520/D6768-04R09.
6. Apparatus
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
6.1 Tensile Testing Machine, a constant rate of extension
Standards volume information, refer to the standard’s Document Summary page on
(CRE) type of testing machine described in Specification D76
the ASTM website.
shall be used with a minimum precision measuring capability
The last approved version of this historical standard is referenced on
-4
www.astm.org. of 0.1 N/m (5.71 × 10 lbf/in.).
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6768 − 04 (2009)
6.2 Clamps, the clamps shall be a minimum 25 by 100 mm below the average for the set of specimens, discard the results
(1 by 4 in.) and with appropriate clamping power to prevent and test another specimen. Continue until the required number
slipping or crushing (damage). of readings has been taken.
6.3 Die or Template, 100 by 200 mm (61 mm) (4 by 8
10. Calculation
in.(60.04 in.)).
10.1 Tensile Strength—Calculate the tensile strength as read
6.4 Miscellaneous, knives, razor, etc, as required.
directly from the test instrument expressed in N/m (lbf/in.) of
width, using the following equation:
7. Sampling and Test Specimens
~α 1α 1…1α !
f1 f2 f5
7.1 Lot Sample—For the lot sample, take rolls of GCLs as
α 5
fn
directed in an applicable material specification, Practice
α
fn
D5889, or as agreed upon between the purchaser and the
α5
W
s
supplier.
where:
7.2 Laboratory
...
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