ASTM D7361-07(2018)

Standard Test Method for Accelerated Compressive Creep of Geosynthetic Materials Based on Time-Temperature Superposition Using the Stepped Isothermal Method

SIGNIFICANCE AND USE
5.1 Use of the SIM decreases the time required for creep to occur and the obtaining of the associated data.  
5.2 The statements set forth in 1.5 are very important in the context of significance and use, as well as scope of the standard.  
5.3 Creep test data are used to calculate the creep modulus of materials as a function of time. These data are then used to predict the long-term creep deformation expected of geosynthetics used in drainage applications.
Note 1: Currently, SIM testing has focused mainly on geonets made from high-density polyethylene. Additional testing on other materials is ongoing.  
5.4 R+H testing is done to establish the range of creep strains experienced in the brief period of very rapid response following the peak of the load ramp.
SCOPE
1.1 This test method covers accelerated testing for compressive creep properties using the stepped isothermal method (SIM).  
1.2 The test method is focused on geosynthetic drainage materials such as HDPE geonet specimens.  
1.3 The SIM tests are laterally unconfined tests based on time-temperature superposition procedures.  
1.4 Ramp and hold (R+H) tests may be completed in conjunction with SIM tests. They are designed to provide additional estimates of the initial rapid compressive creep strain levels appropriate for the SIM results.  
1.5 This method can be used to establish the sustained load compressive creep characteristics of a geosynthetic that demonstrates a relationship between time-dependent behavior and temperature. Results of this method are to be used to augment results of compressive creep tests performed at 20 ± 1 °C and may not be used as the sole basis for determination of long-term compressive creep behavior of geosynthetic material.  
1.6 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.7 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.  
1.8 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: Historical
• Publication Date: 31-Jan-2018
• ICS: 59.080.70 - Geotextiles
• Technical Committee: D35 - Geosynthetics
• Drafting Committee: D35.02 - Endurance Properties

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D7361 − 07 (Reapproved 2018)
Standard Test Method for
Accelerated Compressive Creep of Geosynthetic Materials
Based on Time-Temperature Superposition Using the
Stepped Isothermal Method
This standard is issued under the fixed designation D7361; 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 mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.1 This test method covers accelerated testing for compres-
sive creep properties using the stepped isothermal method
2. Referenced Documents
(SIM).
2.1 ASTM Standards:
1.2 The test method is focused on geosynthetic drainage
D1621 Test Method for Compressive Properties of Rigid
materials such as HDPE geonet specimens.
Cellular Plastics
1.3 The SIM tests are laterally unconfined tests based on
D2990 Test Methods for Tensile, Compressive, and Flexural
time-temperature superposition procedures.
Creep and Creep-Rupture of Plastics
D4439 Terminology for Geosynthetics
1.4 Ramp and hold (R+H) tests may be completed in
D5262 Test Method for Evaluating the Unconfined Tension
conjunction with SIM tests. They are designed to provide
Creep and Creep Rupture Behavior of Geosynthetics
additional estimates of the initial rapid compressive creep
D6364 Test Method for Determining Short-Term Compres-
strain levels appropriate for the SIM results.
sion Behavior of Geosynthetics
1.5 This method can be used to establish the sustained load
compressive creep characteristics of a geosynthetic that dem-
3. Terminology
onstrates a relationship between time-dependent behavior and
3.1 Definitions:
temperature. Results of this method are to be used to augment
3.1.1 For definitions related to geosynthetics, see Terminol-
results of compressive creep tests performed at 20 6 1 °C and
ogy D4439.
may not be used as the sole basis for determination of
3.1.2 For definitions related to creep, see Test Methods
long-term compressive creep behavior of geosynthetic mate-
D2990 and D5262 and Terminology D4439.
rial.
3.2 Definitions of Terms Specific to This Standard:
1.6 The values stated in SI units are to be regarded as the
3.2.1 compressive creep—time-dependent deformation that
standard. The values given in parentheses are for information
occurs when a specimen is subjected to a constant compressive
only.
load.
1.7 This standard does not purport to address all of the
3.2.2 compressive creep modulus—in SIM analysis, the load
safety concerns, if any, associated with its use. It is the
divided by the percent compressive strain at any given point in
responsibility of the user of this standard to establish appro-
time.
priate safety, health, and environmental practices and deter-
3.2.3 dwell time—time during which conditions (particular
mine the applicability of regulatory limitations prior to use.
load) are held constant between temperature steps.
1.8 This international standard was developed in accor-
3.2.4 mean test temperature—the arithmetic average of all
dance with internationally recognized principles on standard-
temperature readings of the atmosphere surrounding the test
ization established in the Decision on Principles for the
specimen for a particular temperature step, starting at a time
Development of International Standards, Guides and Recom-
not later than established temperature ramp time, and finishing
at a time just prior to the subsequent temperature reset.
This test method is under the jurisdiction of ASTM Committee D35 on
Geosynthetics and is the direct responsibility of Subcommittee D35.02 on Endur-
ance Properties. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Feb. 1, 2018. Published February 2018. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 2007. Last previous edition approved in 2012 as D7361 – 07 (2012). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/D7361-07R18. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7361 − 07 (2018)
3.2.5 offset modulus method or pointing—data analysis 6.2 Testing Machine—A universal testing machine or a
method used to normalize any prestrain in the samples by dead-weight loading system with the following capabilities and
shifting the origin of a stress-versus-strain curve to an axis accessories shall be used for testing:
origin of coordinates, that is, to coordinates (0,0). 6.2.1 Load measurement and control,
6.2.2 Strain measurement,
3.2.6 ramp and hold (R+H) test—a creep test of very short
6.2.3 Time measurement,
duration, for example, 100 to 1000 s.
6.2.4 Environmental temperature chamber to facilitate con-
3.2.7 shift factor—the displacement along the log time axis
trol of test conditions,
by which a section of the creep or creep modulus curve is
6.2.4.1 Temperature measurement and control facilities,
moved to create the master curve at the reference temperature.
6.2.5 Other environmental measurement and control, and
Shift factors are denoted by the symbol ~ when the displace-
6.2.6 Computer data acquisition and control.
ments are generally to shorter times (attenuation) or the symbol
a when the displacements are generally to longer times
T
7. Sampling
(acceleration).
7.1 The specimens used for R+H and SIM tests should all be
3.2.8 stepped isothermal method (SIM)—a method of expo-
taken from the same sample.
sure that uses temperature steps and dwell times to accelerate
7.2 Remove one (1) test specimen from the sample for each
creep response of a material being tested under load.
SIM test.
3.2.9 time-temperature superposition—the practice of shift-
7.3 Remove one (1) test specimen from the sample for each
ing viscoelastic response curves obtained at different tempera-
R+H test.
tures along a horizontal log time axis so as to achieve a master
curve covering an extended range of time.
8. Test Specimens
3.2.10 viscoelastic response—refers to polymeric creep,
8.1 Specimens should be at least 120 by 120 mm (4.7 by
strain, stress relaxation, or a combination thereof.
4.7 in.).
4. Summary of Test Method
8.2 Number of Tests:
4.1 SIM—A procedure whereby specified temperature steps
8.2.1 A single specimen is usually sufficient to define a
and dwell times are used to accelerate viscoelastic creep
master creep or relaxation curve using the SIM. However, if
characteristics during which strain and load are monitored as a
only a single SIM test is to be performed, the location of the
function of time.
onset of creep strain or modulus curve should be confirmed
4.1.1 Compressive Creep—Constant compressive load in
using at least two R+H tests.
conjunction with specified temperature steps and dwell times
are used to accelerate compressive creep strain response.
9. Conditioning
4.2 R+H—Test specimens are ramp loaded at a predeter-
9.1 Compression testing via Test Method D6364 and SIM
mined loading rate to a predetermined load and held under
testing shall be conducted using 20 6 1 °C as the reference or
constant load (short-term creep test).
temperature standard. If the laboratory is not within this range,
perform tests in a suitable environmental chamber capable of
5. Significance and Use
controlled cooling and heating. The environmental chamber
5.1 Use of the SIM decreases the time required for creep to
should have a programmable or set-point controller so as to
occur and the obtaining of the associated data.
maintain temperature to 20 6 1 °C. When agreed to, a
5.2 The statements set forth in 1.5 are very important in the
reference temperature other than 20 °C can be utilized. Also,
context of significance and use, as well as scope of the
when agreed to, the results of testing under this standard can be
standard.
shifted from one reference temperature to another.
5.3 Creep test data are used to calculate the creep modulus
9.2 Allow the specimen adequate time to come to tempera-
of materials as a function of time. These data are then used to
ture equilibrium in the laboratory or environmental chamber.
predict the long-term creep deformation expected of geosyn-
Generally, this can be accomplished within a few hours (see
thetics used in drainage applications.
Note 2).
NOTE 1—Currently, SIM testing has focused mainly on geonets made
9.3 Record the relative humidity in the laboratory or envi-
from high-density polyethylene. Additional testing on other materials is
ronmental chamber for all tests.
ongoing.
5.4 R+H testing is done to establish the range of creep
10. Selection of Test Conditions
strains experienced in the brief period of very rapid response
10.1 The standard environment for testing is dry, since the
following the peak of the load ramp.
effect of elevated temperature is to reduce the humidity of
6. Apparatus ambient air without special controls.
6.1 Loading Platens—Loading platens for SIM and R+H 10.2 The standard reference temperature is 20 °C unless
tests should conform to Test Method D6364, Standard Test otherwise agreed to. The individual reference temperature for
Method for Determining the Short-Term Compression Behav- each SIM test is the average achieved temperature of the first
ior of Geosynthetics. dwell time.
D7361 − 07 (2018)
10.3 Testing temperatures are to be within 62 °C of the load is a
...

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: D7361 − 07 (Reapproved 2012) D7361 − 07 (Reapproved 2018)
Standard Test Method for
Accelerated Compressive Creep of Geosynthetic Materials
Based on Time-Temperature Superposition Using the
Stepped Isothermal Method
This standard is issued under the fixed designation D7361; 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 accelerated testing for compressive creep properties using the Stepped Isothermal Methodstepped
isothermal method (SIM).
1.2 The test method is focused on geosynthetic drainage materials such as HDPE geonet specimens.
1.3 The SIM tests are laterally unconfined tests based on time-temperature superposition procedures.
1.4 Ramp and Holdhold (R+H) tests may be completed in conjunction with SIM tests. They are designed to provide additional
estimates of the initial rapid compressive creep strain levels appropriate for the SIM results.
1.5 This method can be used to establish the sustained load compressive creep characteristics of a geosynthetic that
demonstrates a relationship between time-dependent behavior and temperature. Results of this method are to be used to augment
results of compressive creep tests performed at 20 6 1°C1 °C and may not be used as the sole basis for determination of long term
long-term compressive creep behavior of geosynthetic material.
1.6 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.7 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.
1.7 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.
1.8 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:
D1621 Test Method for Compressive Properties of Rigid Cellular Plastics
D2990 Test Methods for Tensile, Compressive, and Flexural Creep and Creep-Rupture of Plastics
D4439 Terminology for Geosynthetics
D5262 Test Method for Evaluating the Unconfined Tension Creep and Creep Rupture Behavior of Geosynthetics
D6364 Test Method for Determining Short-Term Compression Behavior of Geosynthetics
3. Terminology
3.1 Definitions: For definitions related to geosynthetics see Terminology D4439.
3.1 Definitions:For
3.1.1 For definitions related to geosynthetics, see Terminology D4439.
This test method is under the jurisdiction of ASTM Committee D35 on Geosynthetics and is the direct responsibility of Subcommittee D35.02 on Endurance Properties.
Current edition approved July 1, 2012Feb. 1, 2018. Published July 2012February 2018. Originally approved in 2007. Last previous edition approved in 2012 as D7361 – 07
(2012). DOI: 10.1520/D7361-07R12.10.1520/D7361-07R18.
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
D7361 − 07 (2018)
3.1.2 For definitions related to creep, see Test Methods D2990 and D5262 and Terminology D4439.definitions related to creep
see Test Methods D2990, D5262 and D4439.
3.2 Definitions of Terms Specific to This Standard:
3.3.1 viscoelastic response—refers to polymeric creep, strain, stress relaxation or a combination thereof.
3.2.1 compressive creep—time-dependent deformation that occurs when a specimen is subjected to a constant compressive load.
3.2.2 compressive creep modulus—in SIM analysis, the load divided by the percent compressive strain at any given point in
time.
3.2.3 dwell time—time during which conditions (particular load) are held constant between temperature steps.
3.2.4 time-temperature superposition—mean test temperature—the practice of shifting viscoelastic response curves obtained at
different temperatures along a horizontal log time axis so as to achieve a master curve covering an extended range of
time.arithmetic average of all temperature readings of the atmosphere surrounding the test specimen for a particular temperature
step, starting at a time not later than established temperature ramp time, and finishing at a time just prior to the subsequent
temperature reset.
3.2.5 offset modulus method or pointing—data analysis method used to normalize any prestrain in the samples by shifting the
origin of a stress-versus-strain curve to an axis origin of coordinates, that is, to coordinates (0,0).
3.2.6 ramp and hold (R+H) test—a creep test of very short duration, for example, 100 to 1000 s.
3.2.7 shift factor—the displacement along the log time axis by which a section of the creep or creep modulus curve is moved
to create the master curve at the reference temperature. Shift factors are denoted by the symbol ~ when the displacements are
generally to shorter times (attenuation) or the symbol a when the displacements are generally to longer times (acceleration).
T
3.2.8 stepped isothermal method (SIM)—a method of exposure that uses temperature steps and dwell times to accelerate creep
response of a material being tested under load.
3.2.9 mean test temperature—time-temperature superposition—the arithmetic average of all temperature readings of the
atmosphere surrounding the test specimen for a particular temperature step, starting at a time not later than established temperature
ramp time, and finishing at a time just prior to the subsequent temperature reset.practice of shifting viscoelastic response curves
obtained at different temperatures along a horizontal log time axis so as to achieve a master curve covering an extended range of
time.
3.3.7 offset modulus method or pointing—data analysis method used to normalize any prestrain in the samples by shifting the
origin of a stress vs. strain curve to an axis origin of coordinates, that is, to coordinates (0,0).
3.2.10 ramp and hold (R+H) test—viscoelastic response—a creep test of very short duration, for example, 100–1000
seconds.refers to polymeric creep, strain, stress relaxation, or a combination thereof.
3.3.9 dwell time—time during which conditions (particular load) are held constant between temperature steps.
3.3.10 compressive creep modulus—in SIM analysis, the load divided by the percent compressive strain at any given point in
time.
4. Summary of Test Method
4.1 SIM—A procedure whereby specified temperature steps and dwell times are used to accelerate viscoelastic creep
characteristics during which strain and load are monitored as a function of time.
4.1.1 compressive creep—Compressive Creep—Constant compressive load in conjunction with specified temperature steps and
dwell times are used to accelerate compressive creep strain response.
4.2 R+H—Test specimens are ramp loaded at a predetermined loading rate to a predetermined load and held under constant load
(short term (short-term creep test).
5. Significance and Use
5.1 Use of the SIM decreases the time required for creep to occur and the obtaining of the associated data.
5.2 The statements set forth in Section 1.5 are very important in the context of significance and use, as well as scope of the
standard.
5.3 Creep test data are used to calculate the creep modulus of materials as a function of time. These data are then used to predict
the long-term creep deformation expected of geosynthetics used in drainage applications.
NOTE 1—Currently, SIM testing has focused mainly on geonets made from high density high-density polyethylene. Additional testing on other materials
is ongoing.
5.4 R+H testing is done to establish the range of creep strains experienced in the brief period of very rapid response following
the peak of the load ramp.
D7361 − 07 (2018)
6. Apparatus
6.1 Loading Platens—Loading platens for SIM and R+H tests should conform to Test Method D6364, Standard Test Method
for Determining the Short-Term Compression Behavior of Geosynthetics.
6.2 Testing Machine—A universal testing machine or a dead-weight loading system with the following capabilities and
accessories shall be used for testing:
6.2.1 loadLoad measurement and control,
6.2.2 strainStrain measurement,
6.2.3 timeTime measurement,
6.2.4 environmentalEnvironmental temperature chamber to facilitate control of test conditions,
6.2.4.1 temperatureTemperature measurement and control facilities,
6.2.5 otherOther environmental measurement and control, and
6.2.6 computerComputer data acquisition and control.
7. Sampling
7.1 The specimens used for R+H and SIM tests should all be taken from the same sample.
7.2 Remove one (1) test specimen from the sample for each SIM test.
7.3 Remove one (1) test specimen from the sample for each R+H test.
8. Test Specimens
8.1 Specimens should be at least 120 mm × by 120 mm (4.7 in. × 4.7 in.).by 4.7 in.).
8.2 Number of tests—Tests:
8.2.1 A single specimen is usually sufficient to define a master creep or relaxation curve using the SIM. However, if only a single
SIM test is to be performed, the location of the onset of creep strain or modulus curve should be confirmed using at least two R+H
tests.
9. Conditioning
9.1 Compression testing via Test Method D6364 and SIM testing shall be conducted using 20 6 1° C 1 °C as the reference or
temperature standard. If the laboratory is not within this range, perform tests in a suitable environmental chamber capable of
controlled cooling and heating. The environmental chamber should have a programmable-programmable or set-point controller so
as to maintain temperature to 20 6 1°C.1 °C. When agreed to, a reference temperature other than 20°C20
...