ASTM D7748/D7748M-14

Standard Test Method for Flexural Rigidity of Geogrids, Geotextiles and Related Products

SIGNIFICANCE AND USE
5.1 This test method is considered satisfactory for manufacturing quality control testing of a specific geosynthetic; however, caution is advised since information about between-laboratory precision is incomplete. Comparative tests as directed in 5.1.1 may be advisable.  
5.1.1 In case of a dispute arising from differences in reported test results when using this test method for acceptance testing of commercial shipments, the purchaser and the supplier 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 that are from a lot of material of the type in question. 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 statistical analysis 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 supplier must agree to interpret future test results with consideration to the known bias.  
5.2 This test method is not suitable for very limp geosynthetics or those that show a marked tendency to curl or twist at a cut edge.  
5.3 The stiffness of a geosynthetic may change with storage.  
5.4 No evidence has been found showing that bending length is dependent on specimen width. The tendency for specimens to curl or twist will affect the result, because of the rigidity provided at the edge. Consequently, the edge effect is less of an issue for a wider strip.
SCOPE
1.1 This test method covers the measurement of stiffness properties of geogrids, geotextiles and geogrid-geotextile composites all of which are referred to as geosynthetics within this test method. Bending length is measured and flexural rigidity is calculated through use of the cantilever test procedure.  
1.1.1 This test method employs the principle of cantilever bending of the geosynthetic under its own mass.  
1.2 This test method applies to geogrids, geotextiles and geogrid-geotextile composites.  
1.3 This test method is for manufacturing quality control purposes only, to ensure uniformity and consistency of flexural rigidity for a specific product from roll to roll and lot to lot.  
1.4 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.

General Information

• Status: Historical
• Publication Date: 31-Dec-2013
• ICS: 59.080.70 - Geotextiles
• Technical Committee: D35 - Geosynthetics
• Drafting Committee: D35.01 - Mechanical Properties

Relations

• Replaces: ASTM D7748/D7748M-13 - Standard Test Method for Flexural Rigidity of Geogrids, Geotextiles and Related Products
• Effective Date: 01-Jan-2014

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: D7748/D7748M − 14
StandardTest Method for
Flexural Rigidity of Geogrids, Geotextiles and Related
1
Products
This standard is issued under the fixed designation D7748/D7748M; 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 D4439 Terminology for Geosynthetics
E177 Practice for Use of the Terms Precision and Bias in
1.1 This test method covers the measurement of stiffness
ASTM Test Methods
properties of geogrids, geotextiles and geogrid-geotextile com-
E691 Practice for Conducting an Interlaboratory Study to
posites all of which are referred to as geosynthetics within this
Determine the Precision of a Test Method
testmethod.Bendinglengthismeasuredandflexuralrigidityis
calculated through use of the cantilever test procedure.
3. Terminology
1.1.1 This test method employs the principle of cantilever
3.1 For common definitions of terms in this test method,
bending of the geosynthetic under its own mass.
refer to Terminology D123 and Terminology D4439.
1.2 This test method applies to geogrids, geotextiles and
3.2 Definitions of Terms Specific to This Standard:
geogrid-geotextile composites.
3.2.1 bending length, n—a measure of the interaction be-
1.3 This test method is for manufacturing quality control
tween geosynthetic weight and geosynthetic stiffness as shown
purposes only, to ensure uniformity and consistency of flexural
by the way in which a geosynthetic bends under its own
rigidity for a specific product from roll to roll and lot to lot.
weight.
1.4 The values stated in either SI units or inch-pound units
3.2.1.1 Discussion—Bending length reflects the stiffness of
are to be regarded separately as standard. The values stated in
a geosynthetic when bent in one plane under the force of
each system may not be exact equivalents; therefore, each
gravity.
system shall be used independently of the other. Combining
values from the two systems may result in non-conformance 4. Summary of Test Method
with the standard.
4.1 A specimen is slid at a specified rate in a direction
1.5 This standard does not purport to address all of the parallel to its long dimension, until its leading edge projects
safety concerns, if any, associated with its use. It is the from the edge of a horizontal surface. The length of the
responsibility of the user of this standard to establish appro- overhang is measured when the tip of the specimen is de-
priate safety and health practices and determine the applica- pressed under its own mass to the point where the line joining
bility of regulatory limitations prior to use. the top to the edge of the platform makes a 0.724 radians
[41.5°] angle with the horizontal. From this measured length,
2. Referenced Documents
the bending length and flexural rigidity are calculated.
2
2.1 ASTM Standards:
5. Significance and Use
D123 Terminology Relating to Textiles
5.1 This test method is considered satisfactory for manufac-
D1776 Practice for Conditioning and Testing Textiles
D4354 Practice for Sampling of Geosynthetics and Rolled turing quality control testing of a specific geosynthetic;
however, caution is advised since information about between-
Erosion Control Products(RECPs) for Testing
laboratory precision is incomplete. Comparative tests as di-
rected in 5.1.1 may be advisable.
1
This test method is under the jurisdiction of ASTM Committee D35 on
5.1.1 In case of a dispute arising from differences in
Geosynthetics and is the direct responsibility of Subcommittee D35.01 on Mechani-
reported test results when using this test method for acceptance
cal Properties.
testing of commercial shipments, the purchaser and the sup-
Current edition approved Jan. 1, 2014. Published January 2014. Originally
plier should conduct comparative tests to determine if there is
approved in 2012. Last previous edition approved in 2013 as D7748/D7748M–13.
DOI: 10.1520/D7748_D7748M–14.
a statistical bias between their laboratories. Competent statis-
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
tical assistance is recommended for the investigation of bias.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
As a minimum, the two parties should take a group of test
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. specimens that are as homogeneous as possible and that are
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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D7748/D7748M − 14
from a lot of material of the type in question. Te
...

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: D7748/D7748M − 13 D7748/D7748M − 14
Standard Test Method for
Flexural Rigidity of Geogrids, Geotextiles and Related
1
Products
This standard is issued under the fixed designation D7748/D7748M; 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
1.1 This test method covers the measurement of stiffness properties of geogrids, geotextiles and geogrid-geotextile composites
all of which are referred to as geosynthetics within this test method. Bending length is measured and flexural rigidity is calculated
through use of the cantilever test procedure.
1.1.1 This test method employs the principle of cantilever bending of the geosynthetic under its own mass.
1.2 This test method applies to geogrids, geotextiles and geogrid-geotextile composites.
1.3 This test method is for manufacturing quality control purposes only, to ensure uniformity and consistency of flexural rigidity
for a specific product from roll to roll and lot to lot.
1.4 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.
2. Referenced Documents
2
2.1 ASTM Standards:
D123 Terminology Relating to Textiles
D1776 Practice for Conditioning and Testing Textiles
D4354 Practice for Sampling of Geosynthetics and Rolled Erosion Control Products(RECPs) for Testing
D4439 Terminology for Geosynthetics
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3. Terminology
3.1 For common definitions of terms in this test method, refer to Terminology D123 and Terminology D4439.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 bending length, n—a measure of the interaction between geosynthetic weight and geosynthetic stiffness as shown by the
way in which a geosynthetic bends under its own weight.
1
This test method is under the jurisdiction of ASTM Committee D35 on Geosynthetics and is the direct responsibility of Subcommittee D35.01 on Mechanical Properties.
Current edition approved May 1, 2013Jan. 1, 2014. Published May 2013January 2014. Originally approved in 2012. Last previous edition approved in 20122013 as
ε1
D7748–12D7748/D7748M–13. . DOI: 10.1520/D7748_D7748M–13.10.1520/D7748_D7748M–14.
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 Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3.2.1.1 Discussion—
Bending length reflects the stiffness of a geosynthetic when bent in one plane under the force of gravity.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D7748/D7748M − 14
4. Summary of Test Method
4.1 A specimen is slid at a specified rate in a direction parallel to its long dimension, until its leading edge projects from the
edge of a horizontal surface. The length of the overhang is measured when the tip of the specimen is depressed under its own mass
to the point where the line joining the top to the edge of the platform makes a 0.724 radians [41.5°] angle with the horizontal. From
this measured length, the bending length and flexural rigidity are calculated.
5. Significance and Use
5.1 This test method is considered satisfactory for manufacturing quality control testing of a specific geosynthetic; however,
caution is advised since information about between-laboratory precision is incomplete. Comparative tests as directed in 5.1.1 may
be advisable.
5.1.1 In case of a dispute arising from differences in reported test results when using this test method for acceptance testing of
commercial shipments, the purchaser and the supplier shou
...