ASTM D6767-21

Standard Test Method for Pore Size Characteristics of Geotextiles by Capillary Flow Test

SIGNIFICANCE AND USE
5.1 This test method may be used to:  
5.1.1 Determine the pore size distribution of a geotextile,  
5.1.2 Determine the maximum pore size of a geotextile,  
5.1.3 Determine the mean flow pore size of a geotextile,  
5.1.4 Determine the effect of processes such as calendaring or needle punching upon the pore size distribution,  
5.1.5 Determine the effect of compression upon the pore size distribution of a geotextile, if the test equipment allows, and  
5.1.6 Determine the gas flow rate of a geotextile, and thereby its gas flow capability.  
5.2 The pore size distribution test may also be used for research, material development, or to assess clogging on field-retrieved samples.
SCOPE
1.1 This test method covers the determination of the pore size distribution of geotextile filters with pore sizes ranging from 1 to 1000 μm.
Note 1: The accuracy of this procedure has been verified up to a maximum pore size of 500 μm. Above this value, accuracy has been found to be equipment dependent and should be verified by the user through checks on materials with known opening sizes.  
1.2 The test method measures the entire pore size distribution in terms of a surface analysis of specified pore sizes in a geotextile, defined in terms of the limiting diameters.  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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: 30-Apr-2021
• ICS: 59.080.70 - Geotextiles
• Technical Committee: D35 - Geosynthetics
• Drafting Committee: D35.03 - Permeability and Filtration

Relations

• 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: D6767 − 21
Standard Test Method for
Pore Size Characteristics of Geotextiles by Capillary Flow
1
Test
This standard is issued under the fixed designation D6767; 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
1.1 This test method covers the determination of the pore
3. Terminology
size distribution of geotextile filters with pore sizes ranging
3.1 Definitions—For definitions of other terms used in this
from 1 to 1000 µm.
test method, refer to Terminologies D4439 and D1129.
NOTE 1—The accuracy of this procedure has been verified up to a
3.2 Definitions of Terms Specific to This Standard:
maximumporesizeof500µm.Abovethisvalue,accuracyhasbeenfound
3.2.1 bubble point pore size (O ), n—the largest effective
to be equipment dependent and should be verified by the user through 98
checks on materials with known opening sizes.
pore diameter detected by the sudden increase of flow rate at
the beginning of the wet test.
1.2 The test method measures the entire pore size distribu-
tion in terms of a surface analysis of specified pore sizes in a 3.2.2 pore constriction (O), n—diameter of a circle having
geotextile, defined in terms of the limiting diameters. the same area as the smallest section of a given pore.
3.2.3 pore size (O), n—capillary equivalent pore diameter
1.3 The values stated in SI units are to be regarded as
i
for which the percent of total pore diameters i in a given
standard. No other units of measurement are included in this
geotextilebasedonthesurfaceoccupiedbytheporesissmaller
standard.
than or equal to that diameter.
1.4 This standard does not purport to address all of the
3.2.4 pore size distribution (PSD), n—percent cumulative
safety concerns, if any, associated with its use. It is the
distribution of the complete range of pore sizes with in a given
responsibility of the user of this standard to establish appro-
geotextile based on the surface occupied by the pores.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
3.2.5 wetting fluid, n—fluid used to wet the geotextile test
1.5 This international standard was developed in accor-
specimen for the capillary porometry portion of the test
dance with internationally recognized principles on standard-
method, that is, the “wet” test. The verb “wet” is intended to
ization established in the Decision on Principles for the
mean to completely saturate the geotextile specimen with the
Development of International Standards, Guides and Recom-
wetting fluid thoroughly such that the entire thickness of the
mendations issued by the World Trade Organization Technical
specimen contains fluid with no entrained air bubbles.
Barriers to Trade (TBT) Committee.
4. Summary of Test Method
2. Referenced Documents
4.1 Geotextile filters have discrete pores from one side to
2
2.1 ASTM Standards: theotherofthegeotextile.Thebubblepointtestisbasedonthe
D1129 Terminology Relating to Water principle that a wetting fluid is held in these continuous pores
D1193 Specification for Reagent Water by capillary attraction and surface tension, and the minimum
D4354 Practice for Sampling of Geosynthetics and Rolled pressure required to force fluid from these pores is a function
Erosion Control Products (RECPs) for Testing of pore diameter.
4.2 Afluid-wet geotextile will pass air when the applied air
pressure exceeds the capillary attraction of the fluid in the pore
1
This test method is under the jurisdiction of ASTM Committee D35 on
constriction. Smaller pore constrictions will exhibit similar
Geosynthetics and is the direct responsibility of Subcommittee D35.03 on Perme-
ability and Filtration.
behavior at higher pressures. The relationship between pore
Current edition approved May 1, 2021. Published May 2021. Originally
size and pressure has been established for the wetting fluid.
approved in 2002. Last previous edition approved in 2020 as D6767 – 20a. DOI:
10.1520/D6767-21.
4.3 By comparing the gas flow rates of both a wet and dry
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
test at the same pressures, the percentage of the flow passing
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
through the filter pores larger than or equal to the specified size
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. may be calcula
...

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: D6767 − 20a D6767 − 21
Standard Test Method for
Pore Size Characteristics of Geotextiles by Capillary Flow
1
Test
This standard is issued under the fixed designation D6767; 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 determination of the pore size distribution of geotextile filters with pore sizes ranging from 1 to
1000 μm.
NOTE 1—The accuracy of this procedure has been verified up to a maximum pore size of 500 μm. Above this value, accuracy has been found to be
equipment dependent and should be verified by the user through checks on materials with known opening sizes.
1.2 The test method measures the entire pore size distribution in terms of a surface analysis of specified pore sizes in a geotextile,
defined in terms of the limiting diameters.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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:
D1129 Terminology Relating to Water
D1193 Specification for Reagent Water
D4354 Practice for Sampling of Geosynthetics and Rolled Erosion Control Products (RECPs) for Testing
D4439 Terminology for Geosynthetics
3. Terminology
3.1 Definitions—For definitions of other terms used in this test method, refer to Terminologies D4439 and D1129.
3.2 Definitions of Terms Specific to This Standard:
1
This test method is under the jurisdiction of ASTM Committee D35 on Geosynthetics and is the direct responsibility of Subcommittee D35.03 on Permeability and
Filtration.
Current edition approved Dec. 1, 2020May 1, 2021. Published December 2020May 2021. Originally approved in 2002. Last previous edition approved in 2020 as
D6767 – 20.D6767 – 20a. DOI: 10.1520/D6767-20A.10.1520/D6767-21.
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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D6767 − 21
3.2.1 bubble point pore size (O ), n—the largest effective pore diameter detected by the sudden increase of flow rate at the
98
beginning of the wet test.
3.2.2 pore constriction (O), n—diameter of a circle having the same area as the smallest section of a given pore.
3.2.3 pore size (O ), n—capillary equivalent pore diameter for which the percent of total pore diameters i in a given geotextile
i
based on the surface occupied by the pores is smaller than or equal to that diameter.
3.2.4 pore size distribution (PSD), n—percent cumulative distribution of the complete range of pore sizes with in a given
geotextile based on the surface occupied by the pores.
3.2.5 wetting fluid, n—fluid used to wet the geotextile test specimen for the capillary porometry portion of the test method, that
is, the “wet” test. The verb “wet” is intended to mean to completely saturate the geotextile specimen with the wetting fluid
thoroughly such that the entire thickness of the specimen contains fluid with no entrained air bubbles.
4. Summary of Test Method
4.1 Geotextile filters have discrete pores from one side to the other of the geotextile. The bubble point test is based on the principle
that a wetting fluid is held in these continuous pores by capillary attraction and surface tension, and the minimum pressure required
to force fluid from these pores is a function of pore diameter.
4.2 A fluid-wet geotextile will pass air when the applied air pressure exceeds the capillary attraction of the flu
...