ASTM D6767-02
(Test Method)Standard Test Method for Pore Size Characteristics of Geotextiles by Capillary Flow Test
Standard Test Method for Pore Size Characteristics of Geotextiles by Capillary Flow Test
SIGNIFICANCE AND USE
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 calendering or needle punching upon the pore size distribution,
5.1.5 Determine the effect of compression upon the pore size distribution of a geotextile, and
5.1.6 Determine the gas flow rate of a geotextile, and thereby its gas flow capability.
The pore size distribution test is significant not only for indicating pore sizes, but may also indicate a damaged, contaminated, or clogged geotextile.
SCOPE
1.1 This test method covers the determination of the pore size distribution of geotextile filters with pore sizes ranging from 1 to 500 m.
Note 1—The accuracy of this procedure has been verified up to a maximum pore size of 200 m. 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 analyst should be aware that adequate collaborative data for bias statements as required by Practice D 2777 is not provided. See the precision and bias section for details.
1.4 This standard may involve hazardous materials, operations, and equipment. 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.
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Standards Content (Sample)
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Designation:D6767–02
Standard Test Method for
Pore Size Characteristics of Geotextiles by Capillary Flow
Test
This standard is issued under the fixed designation D 6767; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3.2 Definitions of Terms Specific to This Standard:
3.2.1 bubble point pore size (O ), n—the largest effective
1.1 This test method covers the determination of the pore
pore diameter detected by the sudden increase of flow rate at
size distribution of geotextile filters with pore sizes ranging
the beginning of the wet test.
from 1 to 500 µm.
3.2.2 pore constriction (O), n—diameter of a circle having
NOTE 1—The accuracy of this procedure has been verified up to a
the same area as the smallest section of a given pore.
maximum pore size of 200 µm.Above this value accuracy has been found
3.2.3 pore size (O), n—capillary equivalent pore diameter
i
to be equipment dependent and should be verified by the user through
for which the percent of total pore diameters i in a given
checks on materials with known opening sizes.
geotextile based on the surface occupied by the pores are
1.2 The test method measures the entire pore size distribu-
smaller than or equal to that diameter.
tion in terms of a surface analysis of specified pore sizes in a
3.2.4 pore size distribution (PSD), n—percent cumulative
geotextile, defined in terms of the limiting diameters.
distribution of the complete range of pore sizes with in a given
1.3 The analyst should be aware that adequate collaborative
geotextile based on the surface occupied by the pores.
data for bias statements as required by Practice D 2777 is not
3.2.5 wetting liquid, n—liquid used to submerge the geo-
provided. See the precision and bias section for details.
textile specimen prior to beginning the test.
1.4 This standard may involve hazardous materials, opera-
tions, and equipment. This standard does not purport to
4. Summary of Test Method
address all of the safety concerns, if any, associated with its
4.1 Geotextile filters have discrete pores from one side to
use. It is the responsibility of the user of this standard to
theotherofthegeotextile.Thebubblepointtestisbasedonthe
establish appropriate safety and health practices and deter-
principle that a wetting liquid is held in these continuous pores
mine the applicability of regulatory limitations prior to use.
by capillary attraction and surface tension, and the minimum
pressure required to force liquid from these pores is a function
2. Referenced Documents
of pore diameter.
2.1 ASTM Standards:
4.2 Afluid-wet geotextile will pass air when the applied air
D 1129 Definition of Terms Relating to Water
pressure exceeds the capillary attraction of the fluid in the pore
D 2777 Practice for Determination of Precision and Bias of
constriction. Smaller pore constrictions will exhibit similar
Applicable Methods of Committee D-19 on Water
behavior at higher pressures. The relationship between pore
D 4354 Practice for Sampling Geosynthetics (for Testing)
size and pressure has been established for water.
D 4439 Terminology Relating to Geosynthetics
4.3 By comparing the gas flow rates of both a wet and dry
E 128 Test Method for Maximum Pore Diameter and Per-
geotextile at the same pressures, the percentage of the flow
meability of Rigid Porous Filters for Laboratory Use
passing through the filter pores larger than or equal to the
F 316 Pore Size Characteristics of Membrane Filter by
specified size may be calculated from the pressure-size rela-
Bubble Point and Mean Flow Pore Test
tionship. By increasing pressure in small steps, it is possible to
determine the flow contribution of very small pore size
3. Terminology
increments by difference.
3.1 Definitions—For definitions of other terms used in these
test methods, refer to Definitions D 4439 and D 1129.
5. Significance and Use
5.1 This test method may be used to:
This test method is under the jurisdiction of ASTM Committee D35 on 5.1.1 Determine the pore size distribution of a geotextile,
GeosyntheticsandisthedirectresponsibilityofSubcommitteeD35.03onHydraulic
5.1.2 Determine the maximum pore size of a geotextile,
Properties.
5.1.3 Determine the mean flow pore size of a geotextile,
Current edition approved Feb 10, 2002. Published August 2002.
5.1.4 Determine the effect of processes such as calendering
Annual Book of ASTM Standards, Vol 11.01.
Annual Book of ASTM Standards, Vol 04.02.
or needle punching upon the pore size distribution,
Annual Book of ASTM Standards, Vol 14.02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D6767–02
5.1.5 Determine the effect of compression upon the pore sample as directed in Practice D 4354, Section 6 “Procedure
size distribution of a geotextile, and A-Sampling for Specification Conformance.”
5.1.6 Determine the gas flow rate of a geotextile, and 7.2 Laboratory Sample—As a laboratory sample for accep-
thereby its gas flow capability. tance testing, take a full width swatch 1 m long from the end
5.2 The pore size distribution test is significant not only for of each roll of fabric in the lot sample, after first discarding a
indicating pore sizes, but may also indicate a damaged, minimum of1mof fabric from the very outside of the roll.
contaminated, or clogged geotextile. 7.3 Test Specimens—Cut five specimens from each swatch
inthelaboratorysamplewitheachspecimenbeingcuttofitthe
6. Apparatus
appropriate sieve pan. Cut the specimens from a single swatch
6.1 Clean Gas Pressure Source, with regulation (filtered air
spaced along a diagonal line on the swatch.
or nitrogen).
8. Specimen Preparation
6.2 Pressure Transducer, U-tube Manometer or Gage, (or
set of gages), covering the necessary pressure range for the 8.1 Weigh the specimens and then submerge them in dis-
pore sizes under study (see Table 1).
tilled water for 1 h and allow to air dry at the standard
atmosphere for testing.
NOTE 2—Pressure measurements must be installed immediately up-
stream (for example, within 5 mm) of the sample holder.
9. Wetting Liquids
6.3 Closed Filter Holder, (see Fig. 1).
9.1 Purity of Reagents—Reagent grade chemicals shall be
NOTE 3—The filter holder should be checked for leaks by placing a usedforwettingliquidsinalltests.Unlessotherwiseindicated,
geomembrane in the holder and increasing the pressure to 70 kN/m and
it is intended that all reagents shall conform to the specifica-
holding it for a period of one minute.
tionsoftheCommitteeonAnalyticalReagentsoftheAmerican
Chemical Society where such specifications are available.
6.4 Metal Punch, used to cut a suitable size geotextile from
the test sheet to fit the test filter holder. Other grades may be used provided it is first ascertained that
the reagent is of sufficient high purity to permit its use without
6.5 Set of Flowmeters, covering the range from 0 to 100
L/min. lessening the accuracy of the determination.
9.2 Water, conforming to Specification D 1193, Type IV or
NOTE 4—Four flowmeters with flow rates of 0 to 0.4, 0 to 2.5, 0 to 25,
higher purity.
and 0 to 100 L/min, placed in a parallel arrangement to cover the range of
9.3 Denatured Alcohol.
flow rates anticipated are recommended for geotextiles. The smallest flow
9.4 Petroleum Distillate, with surface tension of 30
rate that could be measured by the flowmeters is typically reported to be
0.02 L/min. The manufacturer-rated precision of each flowmeter is dynes/cm at 25°C.
typically reported to be 0.25 percent of the maximum reading.
9.5 Mineral Oil, such as USP liquid petrolatum heavy, with
surface tension of 34.7 dynes/cm at 25°C.
6.6 In-Line Fluid Trap, to protect the flowmeters from the
9.6 1,1,2-trichloro-1,2,2-trifluoret hane. (Freon TFt),avail-
fluid.
able from commercial chemical supply houses.
6.7 Appropriate Fittings, Hose, Connectors, Piping,toas-
9.7 Clean Gas Pressure Source
...
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