ASTM D4632-08

Standard Test Method for Grab Breaking Load and Elongation of Geotextiles

SIGNIFICANCE AND USE
The grab method is applicable whenever it is desired to determine the “effective strength” of the fabric in use, that is, the strength of the material in a specific width, together with the additional strength contributed by adjacent material. There is no simple relationship between grab tests and strip tests since the amount of fabric assistance depends on the construction of the fabric. It is useful as a quality control or acceptance test.
The procedure in Test Method D 4632 for the determination of grab strength of geotextiles may be used for acceptance testing of commercial shipments, but caution is advised since information about between-laboratory precision is incomplete. Comparative tests as directed in 5.2.1 are advisable.
In case of a dispute arising from differences in reported test results when using the procedures in Test Method D 4632 for acceptance testing of commercial shipments, the purchaser and the manufacturer should conduct comparative tests to determine if there is a statistical bias between their laboratories. Competent statistical assistance is recommended for the investigation of bias. As a minimum, the two parties should take a group of test specimens that are as homogeneous as possible and which are from a lot of material of the type in question. The test specimens should then be randomly assigned in equal numbers to each laboratory for testing. The average results from the two laboratories should be compared using the appropriate Student's t-test and an acceptable probability level chosen by the two parties before testing is begun. If a bias is found, either its cause must be found and corrected or the purchaser and the manufacturer must agree to interpret future test results in the light of the known bias.  
Most geotextile fabrics can be tested by this test method. Some modification of clamping techniques may be necessary for a given fabric, depending upon its structure. Special adaptation may be necessary with strong fabrics, or fa...
SCOPE
1.1 This test method is an index test which provides a procedure for determining the breaking load (grab strength) and elongation (grab elongation) of geotextiles using the grab method. This test method is not suitable for knitted fabrics and alternate test methods should be used. While useful for quality control and acceptance testing for a specific fabric structure, the results can only be used comparatively between fabrics with very similar structures, because each different fabric structure performs in a unique and characteristic manner in this test. The grab test methods does not provide all the information needed for all design applications and other test methods should be used.
1.2 Procedures for measuring the breaking load and elongation by the grab method in both the dry and wet state are included; however, testing is normally done in the dry condition unless specified otherwise in an agreement or specification.
1.3 The values stated in SI units are to be regarded as standard. The values stated in inch-pound units are provided for information only.
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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 30-Jun-2008
• ICS: 59.080.70 - Geotextiles
• Technical Committee: D35 - Geosynthetics
• Drafting Committee: D35.01 - Mechanical Properties

Relations

• Replaced By: ASTM D4632/D4632M-08(2013)e1 - Standard Test Method for Grab Breaking Load and Elongation of Geotextiles
• Effective Date: 01-May-2013

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: D4632 − 08
StandardTest Method for
1
Grab Breaking Load and Elongation of Geotextiles
This standard is issued under the fixed designation D4632; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope D2905 Practice for Statements on Number of Specimens for
3
Textiles (Withdrawn 2008)
1.1 This test method is an index test which provides a
D4354 Practice for Sampling of Geosynthetics for Testing
procedure for determining the breaking load (grab strength)
D4439 Terminology for Geosynthetics
and elongation (grab elongation) of geotextiles using the grab
method. This test method is not suitable for knitted fabrics and
3. Terminology
alternate test methods should be used. While useful for quality
3.1 Definitions:
control and acceptance testing for a specific fabric structure,
3.1.1 atmosphere for testing geotextiles, n— air maintained
the results can only be used comparatively between fabrics
at a relative humidity of 65 6 5 % relative humidity and
with very similar structures, because each different fabric
temperature of 21 6 2°C (70 6 4°F).
structure performs in a unique and characteristic manner in this
test.The grab test methods does not provide all the information
3.1.2 breaking load, n—the maximum force applied to a
needed for all design applications and other test methods
specimen in a tensile test carried to rupture.
should be used.
3.1.3 cross-machine direction, n—the direction in the plane
1.2 Procedures for measuring the breaking load and elon-
of the fabric perpendicular to the direction of manufacture.
gation by the grab method in both the dry and wet state are
3.1.4 elongation at break, n—the elongation corresponding
included; however, testing is normally done in the dry condi-
to the breaking load, that is, the maximum load.
tion unless specified otherwise in an agreement or specifica-
3.1.5 geotextile, n—any permeable textile material used
tion.
with foundation, soil, rock, earth, or any other geotechnical
1.3 The values stated in SI units are to be regarded as
material, as an integral part of a man-made product, structure,
standard. The values stated in inch-pound units are provided
or system.
for information only.
3.1.6 grab test, n—in fabric testing, a tension test in which
1.4 This standard does not purport to address all of the
only a part of the width of the specimen is gripped in the
safety concerns, if any, associated with its use. It is the
clamps.
responsibility of the user of this standard to establish appro-
3.1.6.1 Discussion—For example, if the specimen width is
priate safety and health practices and determine the applica-
101.6 mm (4 in.) and the width of the jaw faces 25.4 mm (1
bility of regulatory limitations prior to use.
in.), the specimen is gripped centrally in the clamps.
3.1.7 machine direction, n—the direction in the plane of the
2. Referenced Documents
fabric parallel to the direction of manufacture.
2
2.1 ASTM Standards:
3.1.8 For definitions of other terms used in this test method,
D76 Specification for Tensile Testing Machines for Textiles
refer to Terminology D123 or Terminology D4439.
D123 Terminology Relating to Textiles
D1776 Practice for Conditioning and Testing Textiles
4. Summary of Test Method
4.1 A continually increasing load is applied longitudinally
1
This test method is under the jurisdiction of ASTM Committee D35 on
to the specimen and the test is carried to rupture.Values for the
Geosynthetics and is the direct responsibility of Subcommittee D35.01 on Mechani-
breaking load and elongation of the test specimen are obtained
cal Properties.
CurrenteditionapprovedJuly1,2008.PublishedMay1991.Originallyapproved
from machine scales or dials, autographic recording charts, or
in 1991. Last previous edition approved in 2003 as D4632–91(2003). DOI:
interfaced computers.
10.1520/D4632-08.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
3
Standards volume information, refer to the standard’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D4632 − 08
5. Significance and Use clamp shall be at least as large as its mate. Each jaw face shall
be in line, both with respect to its mate in the same clamp and
5.1 The grab method
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:D4632–91(Reapproved 2003) Designation:D4632–08
Standard Test Method for
1
Grab Breaking Load and Elongation of Geotextiles
This standard is issued under the fixed designation D 4632; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope
1.1 This test method is an index test which provides a procedure for determining the breaking load (grab strength) and
elongation (grab elongation) of geotextiles using the grab method. This test method is not suitable for knitted fabrics and alternate
test methods should be used. While useful for quality control and acceptance testing for a specific fabric structure, the results can
only be used comparatively between fabrics with very similar structures, because each different fabric structure performs in a
unique and characteristic manner in this test. The grab test methods does not provide all the information needed for all design
applications and other test methods should be used.
1.2 Procedures for measuring the breaking load and elongation by the grab method in both the dry and wet state are included;
however, testing is normally done in the dry condition unless specified otherwise in an agreement or specification.
1.3 The values stated in SI units are to be regarded as standard. The values stated in inch-pound units are provided for
information only.
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 and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2
2.1 ASTM Standards:
D 76 Specification for Tensile Testing Machines for Textiles
2
D 123Terminology Relating to Textiles
2
D461Methods of Testing Felt
2
D1682Test Methods for Breaking Load and Elongation of Textile Fabrics Terminology Relating to Textiles
D 1776 Practice for Conditioning Textiles for and Testing Textiles
D 2905 Practice for Statements on Number of Specimens for Textiles
D 4354 Practice for Sampling of Geosynthetics for Testing
3
D 4439Terminology for Geotextiles Terminology for Geosynthetics
3. Terminology
3.1 Definitions:
3.1.1 atmosphere for testing geotextiles, n— air maintained at a relative humidity of 65 6 5 % relative humidity and
temperature of 21 6 2°C (70 6 4°F).
3.1.2 breaking load, n—the maximum force applied to a specimen in a tensile test carried to rupture.
3.1.3 cross-machine direction, n—the direction in the plane of the fabric perpendicular to the direction of manufacture.
3.1.4 elongation at break, n—the elongation corresponding to the breaking load, that is, the maximum load.
3.1.5 geotextile, n—any permeable textile material used with foundation, soil, rock, earth, or any other geotechnical material,
as an integral part of a man-made product, structure, or system.
3.1.6 grab test, n—in fabric testing, a tension test in which only a part of the width of the specimen is gripped in the clamps.
3.1.6.1 Discussion—For example, if the specimen width is 101.6 mm (4 in.) and the width of the jaw faces 25.4 mm (1 in.),
the specimen is gripped centrally in the clamps.
1
This test method is under the jurisdiction ofASTM Committee D35 on Geosynthetics and is the direct responsibility of Subcommittee D35.01 on Mechanical Properties.
Current edition approved June 10, 2003. Published May 1991. Originally published as D4632–86. Last previous edition D4632–86(1990).
Current edition approved July 1, 2008. Published May 1991. Originally approved in 1991. Last previous edition approved in 2003 as D 4632–91(2003).
2
Annual Book of ASTM Standards, Vol 07.01.
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

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D4632–08
3.1.7 machine direction, n—the direction in the plane of the fabric parallel to the direction of manufacture.
3.1.8 For definitions of other terms used in
...