ASTM D4884/D4884M-22

Standard Test Method for Strength of Sewn or Bonded Seams of Geotextiles

SIGNIFICANCE AND USE
5.1 As explained in Test Method D4595, narrow geotextile specimens demonstrate the tendency to contract (neck down) in the gauge area when under stress. The wider width specimen will minimize this phenomenon in seams during strength testing. The results achieved in this test method can more accurately correlate to the seam strength values anticipated in the field.  
5.2 This test method can be used to measure the seam strength of geotextiles from the factory or field, and may also be used for acceptance testing of commercial shipments of geotextiles.  
5.3 This test method can be used to help determine seam design engineering for the geotextiles being evaluated, as well as comparing wet-conditioned specimens with dry specimen results.  
5.4 This test method is not intended to address long-term performance of a seam, nor any of its components such as the thread or the adhesive. However, it can be used as an index value to monitor the behavior of a seam exposed to any particular exposure, in example as part of an effort to assess its long-term performance.
SCOPE
1.1 This test method covers the determination of the factory and field seam strength of geotextiles, using a wide specimen and wet and dry specimens.  
1.2 The long-term performance of a seaming technique is not addressed by this test method. This test method will provide data to indicate the short-term seam strength that can be achieved for each particular geotextile and seam assembly construction. To assess the long-term performance of a seaming technique, it is possible to use Practice D6389, using this test method to determine the anticipated strength reduction in the initial, short-term wide-width tensile strength (Test Method D4595) results.  
1.3 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.  
1.4 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-Jun-2022
• ICS: 59.080.70 - Geotextiles
• Technical Committee: D35 - Geosynthetics
• Drafting Committee: D35.01 - Mechanical Properties

Relations

• Refers: ASTM D4439-24 - Standard Terminology for Geosynthetics
• Effective Date: 01-Feb-2024
• Refers: ASTM D6389-23 - Standard Practice for Tests to Evaluate the Chemical Resistance of Geotextiles to Liquids
• Effective Date: 01-Sep-2023
• Refers: ASTM D1776/D1776M-20 - Standard Practice for Conditioning and Testing Textiles
• Effective Date: 01-Feb-2020
• Refers: ASTM D1777-96(2019) - Standard Test Method for Thickness of Textile Materials
• Effective Date: 01-Jul-2019
• Refers: ASTM D4439-18 - Standard Terminology for Geosynthetics
• Effective Date: 15-Apr-2018
• Refers: ASTM D4439-17 - Standard Terminology for Geosynthetics
• Effective Date: 01-Aug-2017
• Refers: ASTM D6389-17 - Standard Practice for Tests to Evaluate the Chemical Resistance of Geotextiles to Liquids
• Effective Date: 01-Jun-2017
• Refers: ASTM E178-16 - Standard Practice for Dealing With Outlying Observations
• Effective Date: 01-Jun-2016
• Refers: ASTM D6389-99(2016) - Standard Practice for Tests to Evaluate the Chemical Resistance of Geotextiles to Liquids
• Effective Date: 01-Jun-2016
• Refers: ASTM D1776/D1776M-16 - Standard Practice for Conditioning and Testing Textiles
• Effective Date: 01-Jan-2016
• Refers: ASTM D4439-15a - Standard Terminology for Geosynthetics
• Effective Date: 01-Sep-2015
• Refers: ASTM D4439-15 - Standard Terminology for Geosynthetics
• Effective Date: 01-Jul-2015
• Refers: ASTM D1777-96(2015) - Standard Test Method for Thickness of Textile Materials
• Effective Date: 01-Jul-2015
• Refers: ASTM D1776/D1776M-15 - Standard Practice for Conditioning and Testing Textiles
• Effective Date: 01-Feb-2015
• Refers: ASTM D4439-14 - Standard Terminology for Geosynthetics
• Effective Date: 01-Mar-2014

Overview

ASTM D4884/D4884M-22 is the internationally recognized standard test method for determining the strength of sewn or bonded seams in geotextile fabrics. Developed by ASTM International, this standard helps engineers, manufacturers, and contractors accurately assess the seam strength of geotextiles under standardized conditions. By using a wide-width specimen approach, the method minimizes the necking effect observed in narrow samples, providing a more reliable correlation to field performance.

Seam integrity is critical for the proper function of geotextiles in civil engineering, infrastructure, and environmental applications. The standard supports the quality assurance, design, and specification processes for all types of geotextile materials, including those joined by sewing, adhesive bonding, or thermal methods.

Key Topics

• Scope of Testing: Covers both factory and field seams of geotextiles, including evaluation of wet and dry specimens. The method provides data on short-term seam strength but does not address long-term durability.
• Specimen Preparation: Requires wide specimens (typically 200 mm [8 in.] wide) for improved accuracy in simulating field stresses.
• Test Procedure: Involves tensile loading of seam samples using a constant-rate-of-extension machine until rupture, with both the breaking force and failure type recorded.
• Seam Types Covered:
  • Sewn seams (using various stitch types)
  • Thermally bonded seams
  • Adhesive bonded seams
• Data Reporting: Specifies detailed reporting requirements, including seam strength (in kN/m), seam type, machine and cross-machine directions, type of seam failure, and moisture conditions.
• Quality Control: Provides sampling plans for acceptance testing of commercial shipments and field projects, supporting robust quality management practices.
• Safety and Compliance: Requires users to establish appropriate safety, health, and environmental practices for testing.

Applications

ASTM D4884/D4884M-22 is widely applied across geotechnical, environmental, and civil engineering sectors to:

• Quality Assurance and Acceptance Testing: Verify seam integrity in geotextile consignments before delivery and during field installation.
• Seam Engineering & Specification: Assist engineers in designing geotextile assemblies by comparing seam strength across materials, stitch types, adhesives, or bonding techniques.
• Comparative Performance Evaluation: Measure the differences between wet and dry seam strength to predict performance under varied environmental conditions.
• Project Documentation: Provide standardized test data for regulatory compliance, contractor quality records, and project closeout submittals.
• Field Installation Monitoring: Offer an index value to monitor seam behavior after environmental exposure, assisting in long-term durability assessments when used with complementary methods.

Related Standards

Several ASTM and international standards provide essential context or are frequently referenced alongside ASTM D4884/D4884M-22:

• ASTM D4595: Test Method for Tensile Properties of Geotextiles by the Wide-Width Strip Method
• ASTM D6389: Practice for Tests to Evaluate the Chemical Resistance of Geotextiles to Liquids
• ASTM D76/D76M: Specification for Tensile Testing Machines for Textiles
• ASTM D1776/D1776M: Practice for Conditioning and Testing Textiles
• ASTM D4439: Terminology for Geosynthetics
• Federal Standard 751a: Stitches, Seams, and Stitchings

By adhering to ASTM D4884/D4884M-22, organizations ensure consistency, reliability, and international acceptability of geotextile seam testing, supporting robust geosynthetic performance in critical infrastructure projects.

Keywords: geotextile seam strength, sewn seam testing, bonded seam evaluation, ASTM D4884, geotextile quality assurance, wide-width specimen test, geosynthetics standards

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: D4884/D4884M − 22
Standard Test Method for
Strength of Sewn or Bonded Seams of Geotextiles
This standard is issued under the fixed designation D4884/D4884M; 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 D76/D76M Specification for Tensile Testing Machines for
Textiles
1.1 This test method covers the determination of the factory
D1776/D1776M Practice for Conditioning and Testing Tex-
and field seam strength of geotextiles, using a wide specimen
tiles
and wet and dry specimens.
D1777 Test Method for Thickness of Textile Materials
1.2 The long-term performance of a seaming technique is
D4439 Terminology for Geosynthetics
not addressed by this test method. This test method will
D4595 Test Method for Tensile Properties of Geotextiles by
provide data to indicate the short-term seam strength that can
the Wide-Width Strip Method
be achieved for each particular geotextile and seam assembly
D6389 Practice for Tests to Evaluate the Chemical Resis-
construction. To assess the long-term performance of a seam-
tance of Geotextiles to Liquids
ing technique, it is possible to use Practice D6389, using this
E178 Practice for Dealing With Outlying Observations
test method to determine the anticipated strength reduction in
E691 Practice for Conducting an Interlaboratory Study to
the initial, short-term wide-width tensile strength (Test Method
Determine the Precision of a Test Method
D4595) results.
2.2 Federal Standard:
1.3 The values stated in either SI units or inch-pound units
Fed. Std. No. 751a Stitches, Seams, and Stitchings
are to be regarded separately as standard. The values stated in
each system are not necessarily exact equivalents; therefore, to
3. Terminology
ensure conformance with the standard, each system shall be
3.1 For definitions of terms relating to geotextiles, refer to
used independently of the other, and values from the two
Terminology D4439.
systems shall not be combined.
3.2 Definitions of Terms Specific to This Standard:
1.4 This standard does not purport to address all of the
3.2.1 adhered seam, n—in geotextiles, a seam made by the
safety concerns, if any, associated with its use. It is the
application of an adhesive.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter- 3.2.2 seam weld, n—the process by which a seam is formed
through the thermal bonding of separate layers of geotextile.
mine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accor-
3.2.3 selvage, n—the woven edge portion of a geotextile
dance with internationally recognized principles on standard-
parallel to the machine direction.
ization established in the Decision on Principles for the
3.2.4 sewing thread, n—a flexible, small diameter yarn or
Development of International Standards, Guides and Recom-
strand, usually treated with a surface coating, or lubricant, or
mendations issued by the World Trade Organization Technical
both, intended to be used to stitch one or more pieces of
Barriers to Trade (TBT) Committee.
material or an object to a material.
3.2.5 stitch, n—the repeated unit formed by the sewing
2. Referenced Documents
threadintheproductionofseamsinasewngeotextile(seeFed.
2.1 ASTM Standards:
Std. No. 751a).
4. Summary of Test Method
This test method is under the jurisdiction of ASTM Committee D35 on
Geosynthetics and is the direct responsibility of Subcommittee D35.01 on Mechani-
4.1 Material is divided into lots and a lot sample taken as
cal Properties.
described in an applicable material specification, or as agreed
Current edition approved July 1, 2022. Published August 2022. Originally
upon between the purchaser and the supplier.
approvedin1989.Lastpreviouseditionapprovedin2014asD4884/D4884M – 14a.
DOI: 10.1520/D4884_D4884M-22.
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 Available from DLA Document Services, Building 4/D, 700 Robbins Ave.,
the ASTM website. Philadelphia, PA 19111-5094, http://quicksearch.dla.mil.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4884/D4884M − 22
4.2 Specimens with seams are prepared from the samples 7. Sampling and Specimens
per applicable specification or prior agreement between the
7.1 The evaluation of field seams and factory seams will be
purchaser and the supplier; otherwise, prepare at least six test
made by taking samples at the stipulated intervals directed in
specimens.
Table 1 unless otherwise stated.
4.3 A specimen is placed in the test machine with a seam
200 mm [8 in.] wide being gripped on both sides across the
TABLE 1 Seam Quality Control Sampling Requirements
entire width in the clamps depending on the type of seam.
A B
Total Length of Field Sample Interval
Seams for Project, m [yd] Requirements, m [yd]
4.4 The test specimen is subjected to a longitudinal (per-
Up to 10 000 [Up to 11 000] 1000 [1100]
pendicular) force at a prescribed rate of extension until the
10 001 to 150 000 [11 000 to 165 000] 1500 [1666]
seam or geotextile ruptures. 150 000 and up [165 000 and up] 2000 [2200]
A
Total length of field seams for project is the sum of all machine direction and
4.5 Test specimens are evaluated for how they failed and
cross-machine direction seams required to effect installation of geotextile(s).
specimens that are judged invalid are removed from the B
Samples will be taken at stipulated intervals along the total length of the field
analysis. seams. The number of such intervals will be rounded to the next higher whole
number.
5. Significance and Use
5.1 As explained in Test Method D4595, narrow geotextile
NOTE 1—To prevent the unnecessary waste of geotextile or impede the
specimensdemonstratethetendencytocontract(neckdown)in
installation, it should be agreed upon between the supplier and the
the gauge area when under stress. The wider width specimen
purchaserthatallseamsamplescanbetakenfromalternatesidesofpanels
will minimize this phenomenon in seams during strength
at or near the end of the rolls.
testing. The results achieved in this test method can more
7.2 The lengthwise direction of these swatches should be
accurately correlate to the seam strength values anticipated in
parallel to the direction of the seam, either in the machine or
the field.
cross-machine direction.
5.2 This test method can be used to measure the seam
7.2.1 It will be necessary to cut additional swatches for both
strength of geotextiles from the factory or field, and may also
wet and conditioned tests to be performed.
be used for acceptance testing of commercial shipments of
7.3 Prepare test specimens as specified in 7.6.2.
geotextiles.
7.4 Division into Lots and Lot Sample—Divide the material
5.3 This test method can be used to help determine seam
into lots and take a lot sample as described in an applicable
design engineering for the geotextiles being evaluated, as well
materialspecification,orasagreeduponbetweenthepurchaser
as comparing wet-conditioned specimens with dry specimen
and the supplier. In the absence of an applicable material
results.
specification or prior agreement between the purchaser and the
5.4 This test method is not intended to address long-term
supplier, sampling and testing intervals should be agreed upon
performance of a seam, nor any of its components such as the
between the purchaser and the supplier.
thread or the adhesive. However, it can be used as an index
7.4.1 When the installation project requires that seams are
value to monitor the behavior of a seam exposed to any
made in both the machine and cross-machine directions, the
particular exposure, in example as part of an effort to assess its
number of samples and the subsequent specimens will increase
long-term performance.
proportionately.
6. Apparatus
7.5 Laboratory Samples—As a laboratory sample, cut a
minimum of two swatches of geotextile from each of the lot
6.1 Tensile Testing Machine, must be of the constant-rate-
units selected for testing. The swatches must be long and large
of-extension (CRE) type, conforming to Specification D76/
enough to permit seaming and selection of representative
D76M and equipped with a recorder having an adequate pen
sections of seams for specimen preparation, such as, a mini-
response or interfaced computer to record the load elongation
mum of 2000 mm [79 in.] in length and a minimum of 300 mm
curve. The machine must be capable of being set to a rate of
[12 in.] in width. The lengthwise direction of these swatches
extension of 10 6 3 %⁄min.
must be cut from opposite ends and opposite sides of the lot
6.2 Clamps—The clamps shall be wide enough to grip the
samplerollsandshouldbeparalleltothedirectioninwhichthe
entirewidthofthespecimenandhavetheappropriateclamping
seam will be made.
power to hold the test specimen in place without crushing
7.5.1 When seams are made in both the machine and
(damaging) the geotextile.
cross-machine direction, it is suggested that some type of
6.2.1 Caution must be taken to ensure that the type of clamp
special color identification marking be used to distinguish one
used is adequate for the seam strength being measured.
from the other.
7.5.2 These swatches are then joined using the best seam
6.3 Size of Jaw Faces—Each clamp shall have a clamping
face wider than the width of the specimen, typically 225 mm engineering techniques determined by the purchaser and the
[8.86 in.] or larger, and a minimum of 50 mm [2 in.] in the supplier to achieve seam interaction.
direction of the applied force. The size of jaw faces does not 7.5.3 It will be necessary to cut a sufficient number of
apply if roller clamps are used. swatches for both wet and conditioned tests.
D4884/D4884M − 22
7.6 Test Specimens:
7.6.1 Number of Specimens—In the absence of an appli-
cable specification or prior agreement between the purchaser
and the supplier, prepare at least six test specimens from the
laboratory samples.
7.6.2 Test Specimen Size—Prepare test specimens from the
laboratory sample. Each specimen should be approximately
250 mm [10 in.] wide with a stitch line in the center for sewn
seams or approximately 200 mm [8 in.] wide with the seam
weld in the center for thermally bonded or adhered seams
running parallel to either the machine or cross-machine direc-
tions as shown in Fig. 1(a) for sewn seams, Fig. 1(b) for
thermally bonded seams, or Fig. 1(c) for adhered seams.
7.6.2.1 Cut this wider specimen for sewn seams as shown in
Fig. 1(a) to achieve a final test specimen width of 200 mm
[8 in.]. When removing the shaded area from a specimen as
FIG. 1 (b) Test Specimen Preparation for Thermally Bonded Seam
shown in Fig. 1(a), the angles between the 25 mm [1 in.]
(Front View) (continued)
extensionswhichareparalleltotheseamandthatsectionofthe
specimen having a finished width of 200 mm [8 in.] is 90°.
7.6.2.2 For some seaming patterns, cutting the thread may
lead to a loss of the integrity of the seam, and thus to an
underestimation of the seam strength. For these patterns, some
means shall be used to lock the thread in place, such as using
glue, or mechanically locking the thread on both ends of the
seam by unsewing the seam over a maximum length of 25 mm
[1 in.], without damaging the sewing thread, in order to have at
least 200 mm [8 in.] of intact seam cent
...

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: D4884/D4884M − 14a D4884/D4884M − 22
Standard Test Method for
Strength of Sewn or Bonded Seams of Geotextiles
This standard is issued under the fixed designation D4884/D4884M; 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 factory and field seam strength of geotextiles, using a wide specimen.speci-
men and wet and dry specimens.
1.2 The long term long-term performance of a seaming technique is not addressed by this test method. This test method will
provide data to indicate the short term short-term seam strength that can be achieved for each particular geotextile and seam
assembly construction. To assess the long term long-term performance of a seaming technique, it is possible to use Practice D6389,
using this test method to determine the anticipated strength reduction in the initial, short term short-term wide-width tensile
strength (Test Method D4595) results.
1.3 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.
1.4 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 safety, health, and healthenvironmental 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
2.1 ASTM Standards:
D76/D76M Specification for Tensile Testing Machines for Textiles
D1776D1776/D1776M Practice for Conditioning and Testing Textiles
D1777 Test Method for Thickness of Textile Materials
D4439 Terminology for Geosynthetics
D4595 Test Method for Tensile Properties of Geotextiles by the Wide-Width Strip Method
D6389 Practice for Tests to Evaluate the Chemical Resistance of Geotextiles to Liquids
E178 Practice for Dealing With Outlying Observations
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
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 May 1, 2014July 1, 2022. Published June 2014August 2022. Originally approved in 1989. Last previous edition approved in 2014 as
D4884/D4884M – 14.D4884/D4884M – 14a. DOI: 10.1520/D4884_D4884M-14A.10.1520/D4884_D4884M-22.
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
D4884/D4884M − 22
2.2 Federal Standard:
Fed. Std. No. 751a Stitches, Seams, and Stitchings
3. Terminology
3.1 For definitions of terms relating to geotextiles, refer to Terminology D4439.
3.2 Definitions:Definitions of Terms Specific to This Standard:
3.2.1 adhered seam, n—in geotextiles, a seam made by the application of an adhesive.
3.1.2 cross-machine direction—the direction in the plane of the geotextile perpendicular to the direction of manufacture.
3.1.3 geotextile, n—a permeable geosynthetic comprised solely of textiles.
3.1.4 linear density, n—mass per unit length; the quotient obtained by dividing the mass of a fiber or yarn by its length.
3.1.5 machine direction—the direction in the plane of the geotextile parallel to the direction of manufacture.
3.1.6 seam allowance, n—the width of geotextile used in making a seam assembly, for sewn seams bounded by the edge of the
geotextile and the furthest stitch line, and for thermally bonded seams bounded by the edge of the geotextile and the furthest seam
edge.
3.1.6.1 Discussion—
In geotextiles, the distance from the selvage or turned edge of the geotextile to the edge of the seam.
3.1.7 seam assembly, n—the unit obtained by joining geotextile with a seam, including details such as geotextile direction(s), seam
allowance, seam width, seam type, speed, and if sewn—sewing threads used and number of stitches per unit length, needle type
and size, and if adhered – adhesive used, amount of adhesive in weight per unit area, overlap dimension and one or both sides with
adhesive applied and so forth.
3.1.8 seam design engineering, n—the procedures used to select a specific thread, a specific stitch type, and a specific seam type
to achieve the required seam strength of a sewn seam and the procedures used to select a specific seam width, specific seam
bonding temperature, a specific seam speed and pressure to achieve the required seam strength of a thermally bonded seam and
the type and amount of adhesive, overlap dimension and whether the adhesive was applied to one or both sides of the overlap to
achieve the required seam strength of an adhered seam.
3.1.9 seam interaction, n—the result of combining specific textile, a specific stitch type, and a specific seam type for a sewn seam,
the result of combining specific textile, a specific seam width, a specific seam speed, and applied pressure for a thermally bonded
seam and the type and amount of adhesive, overlap dimension and whether the adhesive was applied to one or both sides of the
overlap to achieve the required seam strength of an adhered seam.
3.1.10 seam strength, n—for geotextiles, the maximum resistance, measured in kilonewtons per metre, of the junction formed by
stitching together two or more planar structures.
3.1.11 seam type, n—in sewn geotextiles, an alphanumeric designation relating to the essential characteristics of geotextile
positioning and rows of stitching in a specific sewn geotextile seam (see Fed. Std. No. 751a).
3.1.11.1 Discussion—
The first two letters of the designation show seam type; the third and subsequent letter specify a particular mating alignment; the
number designation indicates the number of rows of stitches.
3.2.2 seam weld, n—the process by which a seam is formed through the thermal bonding of separate layers of geotextile.
3.2.3 selvage, n—the woven edge portion of a geotextile parallel to the machine direction.
Available from DLA Document Services, Building 4/D, 700 Robbins Ave., Philadelphia, PA 19111-5094, http://quicksearch.dla.mil.
D4884/D4884M − 22
3.1.13.1 Discussion—
The edge of a nonwoven geotextile cannot be easily distinguished to determine either the machine or cross-machine direction.
3.2.4 sewing thread, n—a flexible, small diameter yarn or strand, usually treated with a surface coating, or lubricant, or both,
intended to be used to stitch one or more pieces of material or an object to a material.
3.1.15 sewn seam, n—in sewn geotextiles, a series of stitches joining two or more separate plies of a material or materials of planar
structure such as a textile geotextile.
3.2.5 stitch, n—the repeated unit formed by the sewing thread in the production of seams in a sewn geotextile (see Fed. Std. No.
751a).
3.1.17 thermally bonded seam, n—in geotextiles, a seam made by the application of thermal energy.
3.1.18 For definitions of other terms relating to geotextiles, refer to Terminology D4439.
4. Summary of Test Method
4.1 Material is divided into lots and a lot sample taken as described in an applicable material specification, or as agreed upon
between the purchaser and the supplier.
4.2 Specimens with seams are prepared from the samples per applicable specification or prior agreement between the purchaser
and the supplier; otherwise, prepare at least six test specimens.
4.3 A seam, specimen is placed in the test machine with a seam 200 mm [8 in.] wide is gripped being gripped on both sides across
the entire width in the clamps of a tensile testing machine, operated at a prescribed rate of extension, applying a longitudinal
(perpendicular) force to the specimen until the seam or geotextile ruptures.depending on the type of seam.
4.4 The test specimen is subjected to a longitudinal (perpendicular) force at a prescribed rate of extension until the seam or
geotextile ruptures.
4.5 Test specimens are evaluated for how they failed and specimens that are judged invalid are removed from the analysis.
5. Significance and Use
5.1 As explained in Test Method D4595, narrow geotextile specimens demonstrate the tendency to contract (neck down) in the
gagegauge area when under stress. The wider width specimen will minimize this phenomenon in seams during strength testing.
The results achieved in this test method can more accurately correlate to the seam strength values anticipated in the field.
5.2 This test method can be used to measure the seam strength of geotextiles, geotextiles from the factory or field, and may also
be used for acceptance testing of commercial shipments of geotextiles.
5.3 This test method can be used to help determine seam design engineering for the geotextiles being evaluated.evaluated, as well
as comparing wet-conditioned specimens with dry specimen results.
5.4 This test method is not intended to address long term long-term performance of a seam, nor any of its components such as
the thread or the adhesive. However, it can be used as an index value to monitor the behavior of a seam exposed to any particular
exposure, in example as part of an effort to assess its long term long-term performance.
6. Apparatus
6.1 Tensile Testing Machine, must be of the constant-rate-of-extension (CRE) type, conforming to Specification D76/D76M and
equipped with a recorder having an adequate pen response or interfaced computer to record the load elongation curve. The machine
must be capable of being set to a rate of extension of 10 6 3 % ⁄min.
D4884/D4884M − 22
6.2 Clamps—The clamps shall be wide enough to grip the entire width of the specimen and have the appropriate clamping power
to hold the test specimen in place without crushing (damaging) the geotextile.
6.2.1 Caution must be taken to ensure that the type of clamp used is adequate for the seam strength being measured.
6.3 Size of Jaw Faces—Each clamp shall have a clamping face wider than the width of the specimen, typically 225 mm [8.86 in.]
or larger, and a minimum of 50 mm [2 in.] in the direction of the applied force. The size of jaw faces does not apply if roller clamps
are used.
7. Sampling for Acceptance Testing and Number of and Specimens
7.1 The evaluation of field seams and factory seams will be made by taking samples at the stipulated intervals directed in Table
1 unless otherwise stated.
TABLE 1 Seam Quality Control Sampling Requirements
A B
Total Length of Field Sample Interval
Seams for Project, m [yd] Requirements, m [yd]
Up to 10 000 [Up to 11 000] 1000 [1100]
10 001 to 150 000 [11 000 to 165 000] 1500 [1666]
150 000 and up [165 000 and up] 2000 [2200]
A
Total length of field seams for project is the sum of all machine direction and
cross-machine direction seams required to effect installation of geotextile(s).
B
Samples will be taken at stipulated intervals along the total length of the field
seams. The number of such intervals will be rounded to the next higher whole
number.
NOTE 1—To prevent the unnecessary waste of geotextile or impede the installation, it should be agreed upon between the supplier and the purchaser that
all seam samples can be taken from alternate sides of panels at or near the end of the rolls.
7.2 The lengthwise direction of these swatches should be parallel to the direction of the seam, either in the machine or
cross-machine direction.
7.2.1 It will be necessary to cut additional swatches for both wet and conditioned tests to be performed.
7.3 Prepare test specimens as specified in 7.6.2.
7.4 Division into Lots and Lot Sample—Divide the material into lots and take a lot sample as described in an applicable material
specification, or as agreed upon between the purchaser and the supplier. In the absence of an applicable material specification or
prior agreement between the purchaser and the supplier, sampling and testing intervals should be agreed upon between the
purchaser and the supplier.
7.4.1 When the installation project requires that seams are made in both the machine and cross-machine directions, the number
of samples and the subsequent specimens will increase proportionately.
7.5 Laboratory Samples—AtAs a laboratory sample, cut a minimum of two swatches of geotextile from each of the lot units
selected for testing. The swatches must be long and large enough to permit seaming and selection of representative sections of
seams for specimen preparation, such as, a minimum of 2000 mm [79 in.] in length and a minimum of 300 mm [12 in.] in width.
The lengthwise direction of these swatches must be cut from opposite ends and opposite sides of the lot sample rolls and should
be parallel to the direction in which the seam will be made.
7.5.1 When seams are made in both the machine and cross-machine direction, it is suggested that some type of special color
identification marking be used to distinguish one from the other.
7.5.2 These swatches are then joined using the best seam engineering techniques determined by the purchaser and the supplier to
achieve seam interaction.
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7.5.3 It will be necessary to cut a sufficient number of swatches for both wet and conditioned tests.
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7.6 Test Specimens:
7.6.1 Number of Specimens—In the absence of an applicable specification or prior agreement between the purchaser and the
supplier, prepare at least six test specimens from the laboratory samples.
7.6.2 Test Specimen Size—Prepare test specimens from
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