ASTM D4751-21a

Standard Test Methods for Determining Apparent Opening Size of a Geotextile

SIGNIFICANCE AND USE
5.1 Using a geotextile as a medium to retain soil particles necessitates compatibility between it and the adjacent soil. This test method is used to indicate the apparent opening size in a geotextile, which reflects the approximate largest opening dimension available for soil to pass through.  
5.2 Test Methods D4751 for the determination of opening size of geotextiles is acceptable for testing of commercial shipments of geotextiles. Current estimates of precision, between laboratories, have been established.  
5.3 Apparent opening test results obtained using Method A may differ from test results obtained with Method B. It is the intent of this test method to confirm the equivalency of the Method B results before permitting the use of this alternative. Laboratories electing the use of Method B must first determine any bias that exists between the two methods and document a reliable correlation in accordance with this test method.  
5.3.1 The correlation between the Method B results and the Method A results must be established and meet the requirements of this test method for every different geotextile product type tested with Method B. Geotextiles from different manufacturers or with different nominal unit weights are considered different products. A minimum of three test results must be compared with all three satisfying the established correlation.
Note 1: The correlation should be confirmed for a particular product by comparing a minimum of three test results when there are changes in the manufacturing of a specific pre-qualified geotextile.  
5.4 In case of a dispute arising from differences in reported test results when using Test Methods D4751 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 ...
SCOPE
1.1 These test methods cover the determination of the apparent opening size (AOS) of a geotextile either by dry-sieving glass beads through a geotextile (Methods A1 and A2) or by using a capillary porometer (Method B).  
1.2 Method B will not be used in lieu of Method A unless the pre-qualification procedure specified in this standard is followed.  
1.3 These test methods show the values in both SI units and inch-pound units. SI units is the technically correct name for the system of metric units known as the International System of Units. Inch-pound units is the technically correct name for the customary units used in the United States. The values 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 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

• Status: Published
• Publication Date: 31-Aug-2021
• ICS: 59.080.70 - Geotextiles
• Technical Committee: D35 - Geosynthetics
• Drafting Committee: D35.03 - Permeability and Filtration

Relations

• Refers: ASTM D1776/D1776M-20 - Standard Practice for Conditioning and Testing Textiles
• Effective Date: 01-Feb-2020
• Refers: ASTM D4354-12(2020) - Standard Practice for Sampling of Geosynthetics and Rolled Erosion Control Products (RECPs) for Testing
• Effective Date: 01-May-2020

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.
Designation: D4751 − 21a
Standard Test Methods for
1
Determining Apparent Opening Size of a Geotextile
This standard is issued under the fixed designation D4751; 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 U.S. Department of Defense.
1. Scope D1776/D1776M Practice for Conditioning and Testing Tex-
tiles
1.1 These test methods cover the determination of the
D4354 Practice for Sampling of Geosynthetics and Rolled
apparent opening size (AOS) of a geotextile either by dry-
Erosion Control Products (RECPs) for Testing
sieving glass beads through a geotextile (MethodsA1 andA2)
D4439 Terminology for Geosynthetics
or by using a capillary porometer (Method B).
D6767 Test Method for Pore Size Characteristics of Geotex-
1.2 Method B will not be used in lieu of Method A unless
tiles by Capillary Flow Test
the pre-qualification procedure specified in this standard is
E11 Specification for Woven Wire Test Sieve Cloth and Test
followed.
Sieves
E691 Practice for Conducting an Interlaboratory Study to
1.3 These test methods show the values in both SI units and
inch-pound units. SI units is the technically correct name for Determine the Precision of a Test Method
thesystemofmetricunitsknownastheInternationalSystemof
3. Terminology
Units. Inch-pound units is the technically correct name for the
3.1 Definitions—For general geosynthetics terms used in
customary units used in the United States. The values in
this standard, refer to Terminology D4439.
inch-pound units are provided for information only.
3.2 Definitions:
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 3.2.1 apparent opening size(AOS),O , n—for a geotextile,
95
a property that indicates the approximate largest particle that
responsibility of the user of this standard to establish appro-
would effectively pass through the geotextile.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
3.2.1.1 Discussion—While the same “O95” symbol is used
1.5 This international standard was developed in accor-
in Test MethodsA1 and B for defining theAOS of a geotextile
dance with internationally recognized principles on standard-
as well as in Test Method D6767 for determining the pore size
ization established in the Decision on Principles for the
of geotextiles by capillary flow, they are not necessarily
Development of International Standards, Guides and Recom-
equivalent. The O95 values are defined in terms of their
mendations issued by the World Trade Organization Technical
respectivetestmethods.Therefore,theAOSversionoftheO95
Barriers to Trade (TBT) Committee.
value that is determined with Method B may not be identical to
the O95 value determined per Test Method D6767.
2. Referenced Documents
2 4. Summary of Test Methods
2.1 ASTM Standards:
D1331 Test Methods for Surface and Interfacial Tension of
4.1 Glass Bead Dry-Sieving, Method A1—A geotextile
Solutions of Paints, Solvents, Solutions of Surface-Active specimen is placed in a sieve frame, and sized glass beads are
Agents, and Related Materials
placed on the geotextile surface. The geotextile and frame are
shakenlaterallysothatthejarringmotionwillinducethebeads
topassthroughthetestspecimen.Theprocedureisrepeatedon
the same specimen with various size glass beads until a bead
1
These test methods are under the jurisdiction of ASTM Committee D35 on
size with more than 5 % passing and a bead size with less than
Geosynthetics and are the direct responsibility of Subcommittee D35.03 on
Permeability and Filtration.
5 % passing are tested and its apparent opening size has been
Current edition approved Sept. 1, 2021. Published September 2021. Originally
determined. This method is considered the referee method in
approved in 1993. Last previous edition approved in 2021 as D4751 – 21. DOI:
the case of inter-laboratory disputes involving both Methods
10.1520/D4751-21A.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or A2 and B.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
4.2 Method A2—This procedure is strictly intended as a
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. “Pass/Fail” test for manufacturing QC testing. The test is
Copyright © ASTM International, 100 Barr Harbor Driv
...

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: D4751 − 21 D4751 − 21a
Standard Test Methods for
1
Determining Apparent Opening Size of a Geotextile
This standard is issued under the fixed designation D4751; 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 U.S. Department of Defense.
1. Scope
1.1 These test methods cover the determination of the apparent opening size (AOS) of a geotextile either by dry-sieving glass
beads through a geotextile (Method A) (Methods A1 and A2) or by using a capillary porometer (Method B).
1.2 Method B will not be used in lieu of Method A unless the pre-qualification procedure specified in this standard is followed.
1.3 These test methods show the values in both SI units and inch-pound units. SI units is the technically correct name for the
system of metric units known as the International System of Units. Inch-pound units is the technically correct name for the
customary units used in the United States. The values 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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.5 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.
2. Referenced Documents
2
2.1 ASTM Standards:
D1331 Test Methods for Surface and Interfacial Tension of Solutions of Paints, Solvents, Solutions of Surface-Active Agents,
and Related Materials
D1776/D1776M Practice for Conditioning and Testing Textiles
D4354 Practice for Sampling of Geosynthetics and Rolled Erosion Control Products (RECPs) for Testing
D4439 Terminology for Geosynthetics
D6767 Test Method for Pore Size Characteristics of Geotextiles by Capillary Flow Test
E11 Specification for Woven Wire Test Sieve Cloth and Test Sieves
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3. Terminology
3.1 Definitions—For general geosynthetics terms used in this standard, refer to Terminology D4439.
1
These test methods are under the jurisdiction of ASTM Committee D35 on Geosynthetics and are the direct responsibility of Subcommittee D35.03 on Permeability and
Filtration.
Current edition approved July 1, 2021Sept. 1, 2021. Published July 2021September 2021. Originally approved in 1993. Last previous versionedition approved in 20202021
as D4751 – 20b.D4751 – 21. DOI: 10.1520/D4751-21.10.1520/D4751-21A.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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D4751 − 21a
3.2 Definitions:
3.2.1 apparent opening size (AOS),O , n—for a geotextile, a property that indicates the approximate largest particle that would
95
effectively pass through the geotextile.
3.2.1.1 Discussion—
While the same “O95” symbol is used both in these test methods in Test Methods A1 and B for defining the AOS of a geotextile
as well as in Test Method D6767 for determining the pore size of geotextiles by capillary flow, they are not necessarily equivalent.
The O95 values are defined in terms of their respective test methods. Therefore, the AOS version of the O95 value that is
determined with Method B may not be identical to the O95 value determined per Test Method D6767.
4. Summary of Test Methods
4.1 Glass Bead Dry-Sieving, Method A—A1—A geotextile specimen is placed in a sieve frame, and sized glass beads are placed
on the geotextile surface. The geotextile and frame are shaken laterally so that the jarring motion will induce the beads to pass
through the test specimen. The procedure is repeated on the same specimen with various
...