ASTM D4491/D4491M-22

Standard Test Methods for Water Permeability of Geotextiles by Permittivity

SIGNIFICANCE AND USE
5.1 These test methods are considered satisfactory for acceptance testing of commercial shipments of geotextiles since the methods have been used extensively in the trade for acceptance testing.  
5.1.1 In case of a dispute arising from differences in reported test results when using these test methods 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. The test specimens should then be randomly assigned in numbers to each laboratory for testing. The average results from the two laboratories should be compared using Student's t-test for unpaired data and an acceptable probability level chosen by the two parties before the start of testing. 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 in light of the known bias.  
5.1.2 When the dispute involves test results produced with either the Method B falling head test or the Method C air flow test, the Method A constant head test performed with a 50 mm head should be used as the referee method.  
5.1.3 When the dispute involves Method C, the actual water temperature used for the water flow tests must be recorded and the viscosity of water at the test temperature must be used in the conversion from the air flow to water flow as described in Section 16, without the application of the temperature correction.  
5.1.4 Permittivity is an indicator of the quantity of water that can pass through a geotextile in an isolated condition.  
5.1.5 As there are many applications and environmental conditions under which a geotextile may be used, care should be taken when...
SCOPE
1.1 These test methods cover procedures for determining the hydraulic conductivity (water permeability) of geotextiles in terms of permittivity under standard testing conditions, in the uncompressed state. Included are three procedures: the constant head and falling head methods using a water flow apparatus, and the air flow method using an air flow apparatus.  
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.  
1.3 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.  
1.4 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: 30-Apr-2022
• ICS: 59.080.70 - Geotextiles
• Technical Committee: D35 - Geosynthetics
• Drafting Committee: D35.03 - Permeability and Filtration

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: D4491/D4491M − 22
Standard Test Methods for
1
Water Permeability of Geotextiles by Permittivity
This standard is issued under the fixed designation D4491/D4491M; 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 E691Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
1.1 These test methods cover procedures for determining
3
2.2 ASTM Adjuncts:
the hydraulic conductivity (water permeability) of geotextiles
in terms of permittivity under standard testing conditions, in Detailed Drawings and Materials List for Construction, 10
Drawings
the uncompressed state. Included are three procedures: the
constant head and falling head methods using a water flow
3. Terminology
apparatus, and the air flow method using an air flow apparatus.
3.1 Definitions:
1.2 The values stated in either SI units or inch-pound units
3.1.1 geotextile, n—a permeable geosynthetic comprised
are to be regarded separately as standard. The values stated in
solely of textiles.
each system are not necessarily exact equivalents; therefore, to
ensure conformance with the standard, each system shall be
3.1.2 permeability, n—the rate of flow of a liquid under a
used independently of the other, and values from the two
differential pressure through a material.
systems shall not be combined.
3.1.2.1 Discussion—The nominal thickness is used as it is
difficult to evaluate the pressure on the geotextile during the
1.3 This standard does not purport to address all of the
test, thereby making it difficult to determine the thickness of
safety concerns, if any, associated with its use. It is the
the fabric under these test conditions.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
3.1.3 permeability, n—of geotextiles, hydraulic conductiv-
mine the applicability of regulatory limitations prior to use.
ity.
1.4 This international standard was developed in accor-
3.1.4 permittivity, (ψ), (T−1), n—of geotextiles, the volu-
dance with internationally recognized principles on standard-
metric flow rate of water per unit cross-sectional area per unit
ization established in the Decision on Principles for the
head under laminar flow conditions, in the normal direction
Development of International Standards, Guides and Recom-
through a geotextile.
mendations issued by the World Trade Organization Technical
3.1.5 For the definitions of other terms relating to
Barriers to Trade (TBT) Committee.
geotextiles, refer toTerminology D4439. For the definitions of
2. Referenced Documents
textile terms, refer to Terminology D123. For the definition of
2
coefficient of permeability, refer to Terminology D653.
2.1 ASTM Standards:
D123Terminology Relating to Textiles
4. Summary of Test Method
D653Terminology Relating to Soil, Rock, and Contained
Fluids
4.1 Water Flow Test Methods—These test methods describe
D4439Terminology for Geosynthetics
proceduresfordeterminingthepermittivityofgeotextilesusing
D5199Test Method for Measuring the Nominal Thickness
constant head or falling head test procedures with a water flow
of Geosynthetics
apparatus:
4.1.1 MethodA– Constant Head Test—Ahead of 50 mm of
1
These test methods are under the jurisdiction of ASTM Committee D35 on
water is maintained on the geotextile throughout the test. The
Geosynthetics and are the direct responsibility of Subcommittee D35.03 on
quantity of flow is measured versus time. The constant head
Permeability and Filtration.
test is used when the flow rate of water through the geotextile
Current edition approved May 1, 2022. Published June 2022. Originally
approved in 1985. Last previous edition approved in 2021 as D4491/D4491M–21. is so large that it is difficult to obtain readings of head change
DOI: 10.1520/D4491_D4491M-22.
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 Detailed drawings and a materials list for construction are available from
the ASTM website. ASTM International Headquarters. Order Adjunct No. ADJD4491.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1
...

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: D4491/D4491M − 21 D4491/D4491M − 22
Standard Test Methods for
1
Water Permeability of Geotextiles by Permittivity
This standard is issued under the fixed designation D4491/D4491M; 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 procedures for determining the hydraulic conductivity (water permeability) of geotextiles in terms
of permittivity under standard testing conditions, in the uncompressed state. Included are three procedures: the constant head and
falling head methods using a water flow apparatus, and the air flow method using an air flow apparatus.
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each
system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used
independently of the other, and values from the two systems shall not be combined.
1.3 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.
1.4 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:
D123 Terminology Relating to Textiles
D653 Terminology Relating to Soil, Rock, and Contained Fluids
D4439 Terminology for Geosynthetics
D5199 Test Method for Measuring the Nominal Thickness of Geosynthetics
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3
2.2 ASTM Adjuncts:
Detailed Drawings and Materials List for Construction, 10 Drawings
3. Terminology
3.1 Definitions:
3.1.1 geotextile, n—a permeable geosynthetic comprised solely of textiles.
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 May 1, 2021May 1, 2022. Published May 2021June 2022. Originally approved in 1985. Last previous edition approved in 20202021 as
D4491/D4491M – 20.D4491/D4491M – 21. DOI: 10.1520/D4491_D4491M-21.10.1520/D4491_D4491M-22.
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
Detailed drawings and a materials list for construction are available from ASTM International Headquarters. Order Adjunct No. ADJD4491.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D4491/D4491M − 22
3.1.2 permeability, n—the rate of flow of a liquid under a differential pressure through a material.
3.1.2.1 Discussion—
The nominal thickness is used as it is difficult to evaluate the pressure on the geotextile during the test, thereby making it difficult
to determine the thickness of the fabric under these test conditions.
3.1.3 permeability, n—of geotextiles, hydraulic conductivity.
3.1.4 permittivity, (ψ), (T−1), n—of geotextiles, the volumetric flow rate of water per unit cross-sectional area per unit head under
laminar flow conditions, in the normal direction through a geotextile.
3.1.5 For the definitions of other terms relating to geotextiles, refer to Terminology D4439. For the definitions of textile terms,
refer to Terminology D123. For the definition of coefficient of permeability, refer to Terminology D653.
4. Summary of Test Method
4.1 Water Flow Test Methods—These test methods describe procedures for determining the permittivity of geotextiles using
constant head or falling head test procedures with a water flow apparatus:
4.1.1 Method A – Constant Head Test—A head of 50 mm of
...