ASTM D4595/D4595M-24

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of the standard as published by ASTM is to be considered the official document.
Designation: D4595/D4595M − 23 D4595/D4595M − 24
Standard Test Method for
Tensile Properties of Geotextiles by the Wide-Width Method
This standard is issued under the fixed designation D4595/D4595M; 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 tensile properties of geotextiles using a wide-width strip specimen tensile method.
This test method is applicable to most geotextiles that include woven fabrics, nonwoven fabrics,geotextiles, nonwoven geotextiles,
layered fabrics, knit fabrics, and felts and knit fabrics that are used for geotextile application.applications.
1.2 This test method covers the measurement of tensile strength and elongation of geotextiles and includes directions for the
calculation of initial modulus, offset modulus, secant modulus, and breaking toughness.
1.3 Procedures for measuring the tensile properties of both conditioned and wet geotextiles by the wide-width strip method are
included.
1.4 The basic distinction between this test method and other methods for measuring strip tensile properties is the width of the
specimen. Some fabrics used in geotextile applications have a tendency to contract (neck down) under a force in the gage length
area. The greater width of the specimen specified in this test method minimizes the contraction effect of those fabrics and provides
a closer relationship to expected geotextile behavior in the field and a standard comparison.
1.5 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 nonconformance with the standard.
1.6 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.
1.7 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
2.1 ASTM Standards:
D76/D76M Specification for Tensile Testing Machines for Textiles
D123 Terminology Relating to Textiles
D579/D579M Practice for Greige Woven Glass Fabrics
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 April 15, 2023Jan. 15, 2024. Published May 2023February 2024. Originally approved in 1986. Last previous edition approved in 20172023 as
D4595D4595/D4595M – 23. – 17. DOI: 10.1520/D4595_D4595M-23.DOI: 10.1520/D4595_D4595M-24.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. 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
D4595/D4595M − 24
D1776/D1776M Practice for Conditioning and Testing Textiles
D2905 Practice for Statements on Number of Specimens for Textiles (Withdrawn 2008)
D4439 Terminology for Geosynthetics
D4873/D4873M Guide for Identification, Storage, and Handling of Geosynthetic Rolls and Samples
D8102 Practice for Manufacturing Quality Control of Geotextiles
3. Terminology
3.1 atmosphere for testing geotextiles, n—air maintained at a relative humidity of 65 6 5 % and a temperature of 21 6 2 °C [70
6 4 °F].
3.1 Definitions of Terms Specific to This Standard:
−1 −2
3.1.1 breaking toughness, T, (FL ), Jm , n—for geotextiles, the actual work-to-break per unit surface area of material.
3.1.1.1 Discussion—
Breaking toughness is proportional to the area under the force-elongation curve from the origin to the breaking point (see also
work-to-break). Breaking toughness is calculated from work-to-break, gage length, and width of a specimen.
3.1.2 corresponding force, F , n—the force associated with a specific elongation on the force-per-unit-width strain curve. (Syn.
c
load at specified elongation, LASE.)
−1 −2
3.2 breaking toughness, T, (FL ), Jm , n—for geotextiles, the actual work-to-break per unit surface area of material.
3.2.1 Discussion—
Breaking toughness is proportional to the area under the force-elongation curve from the origin to the breaking point (see also
work-to-break). Breaking toughness is calculated from work-to-break, gage length, and width of a specimen.
3.3 corresponding force, F , n—the force associated with a specific elongation on the force-per-unit-width strain curve. (Syn. load
c
at specified elongation, LASE.)
3.4 geotechnical engineering, n—the engineering application of geotechnics.
3.5 geotechnics, n—the application of scientific methods and engineering principles to the acquisition, interpretation, and use of
knowledge of materials of the earth’s crust to the solution of engineering problems.
3.5.1 Discussion—
Geotechnics embraces the fields of soil mechanics, rock mechanics, and many of the engineering aspects of geology, geophysics,
hydrology, and related sciences.
3.6 geotextile, n—any permeable textile material used with foundation, soil, rock, earth, or any other geotechnical engineering
related material, as an integral part of a man-made project, structure, or system.
−1 −1
3.7 initial tensile modulus, J , (FL ), Nm , n—for geotextiles, the ratio of the change in tensile force per unit width to a change
i
in strain (slope) of the initial portion of a force-per-unit-width strain curve.
−1 −1
3.8 offset tensile modulus, J , (FL ), Nm , n—for geotextiles, the ratio of the change in force per unit width to a change in strain
o
(slope) below the proportional limit point and above the tangent point on the force-elongation curve.
3.9 proportional limit, n—the greatest stress which a material is capable of sustaining without any deviation from proportionality
of stress to strain (Hooke’s law).
−1 −1
3.10 secant tensile modulus, J , (FL ), Nm , n—for geotextiles, the ratio of change in force per unit width to a change in strain
sec
(slope) between two points on a force-per-unit-width strain curve.
3.11 tangent point, n—for geotextiles, the first point of the force-elongation curve at which a major decrease in slope occurs.
The last approved version of this historical standard is referenced on www.astm.org.
D4595/D4595M − 24
3.11.1 Discussion—
The tangent point is determined by drawing a tangent line passing through the zero axis and the proportional elastic limit. The point
from the zero-force axis that the force-elongation curve first touches that tangent line is the tangent point.
−1 −1
3.12 tensile modulus, J, (FL ), Nm , n—for geotextiles, the ratio of the change in tensile force per unit width to a corresponding
change in strain (slope).
3.13 tensile strength, n—for geotextiles, the maximum resistance to deformation developed for a specific material when subjected
to tension by an external force.
3.13.1 Discussion—
Tensile strength of geotextiles is the characteristic of a sample as distinct from a specimen and is expressed as force per unit width.
3.14 tensile test, n—in textiles, a test in which a textile material is stretched in one direction to determine the force-elongation
characteristics, the breaking force, or the breaking elongation.
3.15 wide-width strip tensile test, n—for geotextiles, a uniaxial tensile test in which the entire width of a 200 mm [8.0 in.] wide
specimen is gripped in the clamps and the gage length is 100 mm [4.0 in.].
3.16 work-to-break, W, (LF), n—in tensile testing, the total energy required to rupture a specimen.
3.16.1 Discussion—
For geotextiles, work-to-break is proportional to the area under the force-elongation curve from the origin to the breaking point,
and is commonly expressed in joules [inch-pound force].
3.17 yield point, n—the first point of the force-elongation curve above the proportional (linear) section at which an increase in
elongation occurs without a corresponding increase in force.
3.2 For terminology of other terms used in this test method, refer to Terminology D123 and Terminology D4439.
4. Summary of Test Method
4.1 A relatively wide specimen is gripped across its entire width in the clamps of a constant rate of extension (CRE) type tensile
testing machine operated at a prescribed rate of extension, applying a longitudinal force to the specimen until the specimen
ruptures. Tensile strength, elongation, initial and secant modulus, and breaking toughness of the test specimen can be calculated
from machine scales, dials, recording charts, or an interfaced computer.
5. Significance and Use
5.1 The determination of the wide-width strip force-elongation properties of geotextiles provides design parameters for
reinforcement type applications, for example, design of reinforced roadways/pavements, reinforced embankments over soft
subgrades, reinforced soil retaining walls, and reinforcement of slopes. When strength is not necessarily a design consideration,
an alternative test method may be used for acceptance testing. Test Method D4595/D4595M for the determination of the
wide-width strip tensile properties of geotextiles may be used for the acceptance testing of commercial shipments of geotextiles,
but caution is advised since information about between-laboratory precision is incomplete (Note 63). Comparative tests as directed
in 5.1.1 may be advisable.
5.1.1 In cases of a dispute arising from differences in reported test results when using Test Method D4595/D4595M 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. At a
minimum, the two parties should take a group of test specimens which are as homogeneous as possible and which are from a lot
of material of the type in question. The 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 Student’s t-test for unpaired data and an acceptable
probability level chosen by the two parties before the testing began. 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.
5.2 Most geotextiles can be tested by this test method. Some modification of clamping techniques may be necessary for a given
geotextile depending upon its structure. Special clamping adaptions may be necessary with strong geotextiles or geotextiles made
D4595/D4595M − 24
FIG. 1 WedgeHydraulic Clamps
from glass fibers to prevent them from slipping in the clamps or being damaged as a result of being gripped in the clamps.
Specimen clamping may be modified as required at the discretion of the individual laboratory, provided a representative tensile
strength is obtained. In any event, the procedure described in Section 10 of this test method for obtaining wide-width strip tensile
strength must be maintained.
5.3 This test method is applicable for testing geotextiles either dry or wet. It is used with a constant-rate-of-extension type tension
apparatus.
5.4 The use of tensile strength test methods that restrict the clamped width dimension to 50 mm [2 in.] or less, such as the ravel,
cut strip, and grab test procedures, have been found less suitable than this test method for determining design strength parameters
for some geotextiles. This is particularly the case for nonwoven geotextiles. The wide-width strip technique has been explored by
the industry and is recommended in these cases for geotextile applications.
5.4.1 This test method may not be suited for some woven fabrics used in geotextile applications that exhibit strengths
approximately 100 kN/m or 600 lbf/in. due to clamping and equipment limitations. In those cases, 100 mm [4 in.] width specimens
may be substituted for 200 mm [8 in.] width specimens. On those fabrics, the contraction effect cited in 1.4 is minimal and,
consequently, the standard comparison can continue to be made.
6. Apparatus and Reagents
6.1 Tensile Testing Machine—A constant rate of extension (CRE) type of testing machine described in Specification D76/D76M
shall be used. When using the CRE-type tensile tester, the recorder must have adequate pen response to properly record the
force-elongation curve as specified in Specification D76/D76M.
6.2 Clamps—The clamps shall be sufficiently wide to grip the entire width of the sample and with appropriate clamping power
to prevent slipping or crushing (damage).
6.2.1 There are several types of clamp designs available. Three basic clamp design examples are shown in Figs. 1-3Fig. 1. These
designs have been used in the laboratory and have provided reproducible tensile strengths. These clamps may be modified to
provide greater ease and speed of clamping. In any event, caution must be taken to ensure the type material and dimensions of the
clamp are adequate for the user’s expected fabric strength. Additional guidance Guidance is given in Appendix X5Table 1.
6.2.2 Size of Jaw Faces—Each clamp shall have jaw faces measuring wider than the width of the specimen, 200 mm [8 in.], and
a minimum of 50 mm [2 in.] length in the direction of the applied force.
D4595/D4595M − 24
TABLE X5.11 Wide-Width Tensile Clamping Guide
NOTE 1—Clamp type guidance is independent of strain measurement procedure and only addresses strength measurement.
NOTE 2—The success in applying individual clamping arrangements is dependent upon successful selection of grip faces and surfacing.
NOTE 3—If failures are cascading failures or jaw breaks, the clamping apparatus needs to be reconsidered or the bond with the clamp re-examined.
See 10.5.3 for more guidance.
NOTE 4—The yarn type, for example, tape, monofilament, fibrillated, can play a significant role in the clamp selection.
Hydraulic
Capstan
Hydraulic “Smart” Capstan Coil
Clamp Type single
Plate (pressure multi- wrap Wedge
wrap
sensitive)
Material Type
Material Type and Strength
High Strength x x
Clamp Type
Strap
Pneumatic Plate Hydraulic “Smart” Plate Capstain Roller Single Wrap Capstain Roller Multi-Wrap
<1000 lb/in. x x
Nonwoven
Geotextile
Nonwoven = =
geotextile up to 90 kN/m [500 lb/in.]
>1000 lb/in. x
Nonwoven Geotextile
Nonwoven geotextile greater than 90 =
kN/m [500 lb/in.]
>1000 lb/in. Woven Geotextile x x
>500 lb/in. x x x
Woven Geotextile
Woven/knitted geotextile = = = =
up to 55 kN/m [300 lb/in.]
<500 lb/in. x x x x
Woven Geotextile
Glass GG and x x
Meshes
Woven/knitted geotextile greater = = =
than 55 kN/m [300 lb/in.] but not
greater than 175 kN/m [1000 lb/in.]
Woven/knitted geotextile greater than = =
175 kN/m [lb/in.]
Example Curtis clamps Demgen clamps Linear
Composite
Clamps
Example Curtis clamps Demgen clamps
6.3 External extensometers or other external means of measurement are required for all tests where modulus is to be measured.
The clamping mechanism and weight of the extensometer shall not affect the tensile performance of the geotextile, such as breaks
occurring or initiating at the extensometer clamp. In this case, the distance between the moving feet of the extensometer determines
the gage length for use in elongation calculations and not test speed. Examples of contact and noncontact extensometers are shown
in Figs. 5-2 and 37. Please see Note 63 and Appendix X5Table 1.
6.4 Area-Measuring Device—Use an integrating accessory to the tensile testing machine or a planimeter.
6.5 Distilled Water and Nonionic Wetting Agent, for wet specimens only.
7. Sampling
7.1 Lot Sample—For the lot sample, take rolls of geotextiles as directed in an applicable material specification, or as agreed upon
between the purchaser and the supplier.
NOTE 1—The extent of the sampling for wide-width strip tensile properties is generally defined in an applicable order or contract. Among the options
D4595/D4595M − 24
FIG. 52 Sanders ClampContact Extensometers
FIG. 63 Noncontact Extensometer
available to the purchaser and the supplier is for the purchaser to accept certification by the manufacturer that the material in question meets the
requirements agreed upon by the two parties, and what the basis for the certification is, such as, historical data generated from material manufactured
under the same conditions.
7.2 Laboratory Sample—For the laboratory sample, take a full-width swatch from each roll in the lot sample. The sample may
be taken from the end portion of a roll, provided there is no evidence it is distorted or different from other portions of the roll. In
cases of dispute, take a sample that will exclude fabric from the outer wrap of the roll or the inner wrap around the core.
7.3 Test Specimens—For tests in the machine direction and the cross-machine direction, respectively, take from each swatch in the
laboratory sample the number of specimens directed in Section 8. Take specimens at random from the laboratory sample, with
those for the measurement of the machine direction tensile properties from different positions across the geotextile width, and the
specimens for the measurement of the cross-machine direction tensile properties from different positions along the length of the
geotextile. Take no specimens nearer the selvage or edge of the geotextile than one tenth the width of the geotextile (see 8.2).
8. Test Specimen Preparation
8.1 Number of Specimens:
D4595/D4595M − 24
TABLE 12 Values of Student’s t for One-Sided Limits and the
A
95 % Probability
df One-Sided df One-Sided df One-Sided
1 6.314 11 1.796 22 1.717
2 2.920 12 1.782 24 1.711
3 2.353 13 1.771 26 1.706
4 2.132 14 1.761 28 1.701
5 2.015 15 1.753 30 1.697
6 1.943 16 1.746 40 1.684
7 1.895 17 1.740 50 1.676
8 1.860 18 1.734 60 1.671
9 1.833 19 1.729 120 1.658
10 1.812 20 1.725 ` 1.645
A
Values in this table were calculated using Hewlett Packard HP 67/97 Users’
Library Programs 03848D, “One-Sided and Two-Sided Critical Values of Student’s
t” and 00350D, “Improved Normal and Inverse Distribution.” For values at other
than the 95 % probability level, see published tables of critical values of Student’s
t in any standard statistical text. Further use of this table is defined in Practice
D2905.
8.1.1 Unless otherwise agreed upon, as when specified in an applicable material specification, take a number of specimens per
fabric swatch such that the user may expect at the 95 % probability level that the test result is not more than 5.0 % of the average
above or below the true average of the swatch for each the machine and cross-machine direction, respectively. Determine the
number of specimens as follows:
8.1.2 Reliable Estimate of v—Unless otherwise agreed upon, as when specified in an applicable material specification, take a
number When there is a reliable estimate of specimensv per fabric swatch such that the user may expect at the 95 % probability
level that the test result is not more than 5.0 % of the average above or below the true average of the swatch for each the machine
and cross-machine direction, respectively. Determine the based upon extensive past records for similar materials tested in the user’s
laboratory as directed in the method, calculate the required number of specimens using Eq 1, as follows:
n 5 tv/A (1)
~ !
8.1.1.1 Reliable Estimate of v—When there is a reliable estimate of v based upon extensive past records for similar materials tested
in the user’s laboratory as directed in the method, calculate the required number of specimens using Eq 1, as follows:
n 5 tv/A (1)
~ !
where:
n = number of specimens (rounded upward to a whole number),
v = reliable estimate of the coefficient of variation of individual observations on similar materials in the user’s laboratory under
conditions of single-operator precision, %,
t = the value of Student’s t for one-sided limits (see Table 1), a 95 % probability level, and the degrees of freedom associated
with the estimate of v, and
A = 5.0 % of the average, the value of the allowable variation.
where:
n = number of specimens (rounded upward to a whole number),
v = reliable estimate of the coefficient of variation of individual observations on similar materials in the user’s laboratory under
conditions of single-operator precision, %,
t = the value of Student’s t for one-sided limits (see Table 2), a 95 % probability level, and the degrees of freedom associated
with the estimate of v, and
A = 5.0 % of the average, the value of the allowable variation.
8.1.1.2 No Reliable Estimate of v—When there is no reliable estimate of v for the user’s laboratory, Eq 1 should not be used
directly. Instead, specify the fixed number of six specimens for each the machine direction and the cross-machine direction tests.
The number of specimens is calculated using v = 7.4 % of the average. This value for v is somewhat larger than usually found in
practice. When a reliable estimate of v for the user’s laboratory becomes available, Eq 1 will usually require fewer than the fixed
number of specimens.
D4595/D4595M − 24
8.1.3 No Reliable Estimate of v—When there is no reliable estimate of v for the user’s laboratory, Eq 1 should not be used directly.
Instead, specify the fixed number of five specimens each for the machine direction and the cross-machine direction tests. The
number of specimens is calculated using v = 7.4 % of the average. This value for v is somewhat larger than usually found in
practice. When a reliable estimate of v for the user’s laboratory becomes available, Eq 1 will usually require fewer than the fixed
number of specimens.
8.2 Test Specimen Size:
8.2.1 Prepare each finished specimen 200 mm [8.0 in.] wide (excluding fringe when applicable, see 8.2.2) by at least 200 mm
[8.0 in.] long (see 8.2.2) with the length dimension being designated and accurately parallel to the direction for which the tensile
strength is being measured. If necessary, centrally, draw two lines running the full width of the specimen, accurately perpendicular
to the length dimension and separated by 100 mm [4 in.] to designate the gage area (see 5.4.1 and Note 63).
8.2.2 For some woven geotextiles, it may be necessary to cut each specimen 210 mm [8.5 in.] wide and then remove an equal
number of yarns from each side to obtain the 200 mm [8.0 in.] finished dimension. This helps maintain specimen integrity during
the test.
8.2.3 The length of the specimen depends upon the type of clamps being used. It must be long enough to extend through the full
length of both clamps, as determined for the direction of test.
8.2.4 When specimen integrity is not affected, the specimens may be initially cut to the finished width.
8.2.5 When the wet tensile strength of the fabric is required in addition to the dry tensile strength, cut each test specimen at least
twice as long as is required for a standard test (see Note 1). Number each specimen and then cut it crosswise into two parts, one
for determining the conditioned tensile strength and the other for determining the wet tensile strength; each portion shall bear the
specimen number. In this manner, each paired break is performed on test specimens containing
...