Standard Test Method for Conducting Time-to-Failure (Creep-Rupture) Tests of Joints Fabricated from Nonbituminous Organic Roof Membrane Material

SIGNIFICANCE AND USE
An important factor affecting the performance of joints of nonbituminous membranes is their ability to remain bonded over the membrane’expected service life. Time-to-failure tests provide a means of characterizing the behavior of joints under constant load over time.
Creep is a sensitive index of rheological properties that depend on material, load, temperature, and time. Time-to-failure data that are obtained over a relatively short time period can evaluate one factor affecting a joint’ability to withstand static loading over a relatively long time period.
Time-to-failure data for joints of nonbituminous organic roof membrane specimens can be used for the following: (1) to provide a measure of the load-carrying ability of the joint as a function of time at various levels of load, temperature, and relative humidity; (2) to characterize the joint with regard to factors affecting performance, such as surface preparation of the adherend, solvent-based adhesive thickness and open time, environment during adhesive application and cure, and temperature of thermal welding processes; and (3) to compare the effects of different bonding processes or adhesive bonding materials on joint performance.
While it is considered that the results obtained by this laboratory test may afford a measure of the performance of seams in service, provided that load, temperature, and humidity conditions are known, no direct correlation has been established.
SCOPE
1.1 This test method covers laboratory determination of the time-to-failure (creep-rupture) of joints fabricated from nonbituminous organic roof membrane material. The test method covers both T-peel and lap-shear joints subjected to constant tensile load under controlled environmental conditions. The joints, made from either unreinforced or fabric-reinforced membrane material, are prepared in the laboratory or sampled from roofs in service.
1.2 Sheet materials from which the joints are fabricated include vulcanized rubbers, nonvulcanized polymeric sheets, and thermoplastics. The bonding methods for joint formation include the use of liquid-based adhesives, preformed tapes, and thermal and solvent weld processes.
1.3 The values stated in S.I. units are to be regarded as the standard. The values given in parentheses are for information only.
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 and health practices and determine the applicability of regulatory limitations prior to use.

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ASTM D5405-98(2004) - Standard Test Method for Conducting Time-to-Failure (Creep-Rupture) Tests of Joints Fabricated from Nonbituminous Organic Roof Membrane Material
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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: D5405 – 98 (Reapproved 2004)
Standard Test Method for
Conducting Time-to-Failure (Creep-Rupture) Tests of Joints
Fabricated from Nonbituminous Organic Roof Membrane
Material
This standard is issued under the fixed designation D5405; 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 3. Terminology
1.1 This test method covers laboratory determination of the 3.1 Definitions—For definitions of terms used in this test
time-to-failure (creep-rupture) of joints fabricated from nonbi- method, refer to Terminology D907 and D1079.
tuminous organic roof membrane material. The test method 3.2 Definitions of Terms Specific to This Standard:
covers both T-peel and lap-shear joints subjected to constant 3.2.1 creep-rupture test—a test that measures the time-to-
tensile load under controlled environmental conditions. The failure of a specimen subjected to a constant load; progressive
joints, made from either unreinforced or fabric-reinforced specimen deformation may also be measured.
membrane material, are prepared in the laboratory or sampled 3.2.2 failure—rupture of the bond resulting in complete
from roofs in service. separation of its adherends under the test conditions; or,
1.2 Sheet materials from which the joints are fabricated alternatively, rupture of the membrane material away from the
include vulcanized rubbers, nonvulcanized polymeric sheets, bonded section of the test specimen (that is, material rupture).
and thermoplastics. The bonding methods for joint formation 3.2.3 time-to-failure—the period of time beginning when a
includetheuseofliquid-basedadhesives,preformedtapes,and joint specimen is placed under load and ending when failure
thermal and solvent weld processes. occurs.
1.3 The values stated in S.I. units are to be regarded as the
4. Summary of Test Method
standard. The values given in parentheses are for information
4.1 This test method is a creep-rupture test without mea-
only.
1.4 This standard does not purport to address all of the surement of specimen deformation. The time-to-failure, in
safety concerns, if any, associated with its use. It is the hours, of joints fabricated from nonbituminous organic roof
membrane materials is measured when subject to constant
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- deadweight loads under controlled temperature and humidity
conditions.
bility of regulatory limitations prior to use.
2. Referenced Documents 5. Significance and Use
5.1 An important factor affecting the performance of joints
2.1 ASTM Standards:
D816 Test Methods for Rubber Cements of nonbituminous membranes is their ability to remain bonded
over the membrane’s expected service life. Time-to-failure
D907 Terminology of Adhesives
D1079 Terminology Relating to Roofing andWaterproofing tests provide a means of characterizing the behavior of joints
under constant load over time.
D1876 Test Method for Peel Resistance of Adhesives (T-
Peel Test) 5.2 Creep is a sensitive index of rheological properties that
depend on material, load, temperature, and time. Time-to-
failure data that are obtained over a relatively short time period
This test method is under the jurisdiction ofASTM Committee D08 on Roofing can evaluate one factor affecting a joint’s ability to withstand
and Waterproofing and is the direct responsibility of Subcommittee D08.18 on
static loading over a relatively long time period.
Nonbituminous Organic Roof Coverings.
5.3 Time-to-failure data for joints of nonbituminous organic
Current edition approved July 1, 2004. Published July 2004. Originally approved
roof membrane specimens can be used for the following: (1)to
in 1993. Last previous edition approved in 1998 as D5405 – 98. DOI: 10.1520/
D5405-98R04.
provide a measure of the load-carrying ability of the joint as a
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
function of time at various levels of load, temperature, and
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
relative humidity; (2) to characterize the joint with regard to
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. factors affecting performance, such as surface preparation of
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D5405 – 98 (2004)
the adherend, solvent-based adhesive thickness and open time,
environment during adhesive application and cure, and tem-
perature of thermal welding processes; and (3) to compare the
effects of different bonding processes or adhesive bonding
materials on joint performance.
5.4 While it is considered that the results obtained by this
laboratory test may afford a measure of the performance of
seamsinservice,providedthatload,temperature,andhumidity
conditions are known, no direct correlation has been estab-
lished.
6. Apparatus
6.1 Test Chamber, of sufficient size to hold a minimum of
15 specimens. The height of the chamber shall be sufficient to
allow suspension of the deadweight loads and specimen
deformation during testing. The chamber shall be structurally
capable of supporting the loads anticipated during testing
without appreciable deflection.
NOTE 1—A minimum height of 600 mm (24 in.) is suitable for the
specimen sizes described in this test method if they are not extremely
extensible. A taller chamber may be needed if they are extremely
extensible.
FIG. 1 Schematic of a T-Peel Specimen Clamped Under Load
6.1.1 Temperature and Humidity Control—The control of
temperature and humidity is important, since small changes in
these variables may produce large changes in time-to-failure.
NOTE 4—If each specimen has its own timer device (see 6.5), it is not
The temperature and relative humidity within the chamber
necessary to load all specimens simultaneously.
shall be controlled within 63°C (6 5°F) and 65 % relative
humidity, respectively, over the duration of the test. Any 6.5 Timer Device, for recording the total time over which
deviations from these limits shall be given in the test report. eachindividualspecimenisunderload,orformarkingthetime
The selected temperature and humidity conditions shall be at which failure of each specimen occurs.The sensitivity of the
uniform throughout the enclosed space (63°C or 65°F and timer shall be as follows:
65 %relativehumidity).Ifthisuniformityisachievedthrough
Failure Time Timer Sensitivity
#25 h 0.1 min
mechanical air circulation, it shall not cause the specimens to
>25 and#100 h 0.01 h
sway, vibrate, or be otherwise disturbed.
>100 h 0.1 h
NOTE 2—Suggested test conditions are as follows: (1) normal ambient
NOTE 5—For investigations involving multiple specimens in the cham-
temperature (approximately 23°C or 73°F) and humidity (50 % relative
ber, a computer-controlled timer that records the time-to-failure has been
humidity); and (2) extremes to which the seams may be subjected in
found to be satisfactory. In this case, a micro-electrical circuit connected
service.
to the computer is set up for each specimen. The circuit consists of a wire
loop,ofwhichonesegmentisashortlengthofwire(triggerwire)attached
6.2 Specimen and Load Clamping—The chamber shall be
to each grip on the test specimen and set to stop the computer clock when
equipped with a means for clamping the joint specimens
failure occurs. At the point of attachment at the top grip, the trigger wire
vertically to the top of the interior of the chamber, or other
is inserted in an electrical connector. When the specimen fails and the
suitable upper support. Also, a clamp shall be provided to
deadweight on the lower grip falls, the trigger wire is pulled from the
secure the deadweight loads to the bottom of the joint connector, breaking the circuit and stopping the clock.
specimens. Figs. 1 and 2 show a suggested clamping arrange-
7. Vibration Control
ment including the deadweight load.
6.3 Deadweight Loads, of appropriate mass (see Section
7.1 Because the time-to-failure tests are sensitive to vibra-
10).
tion, select a location of the testing apparatus for minimum
disturbance.Whenavibration-freelocationisnotavailable,the
NOTE 3—It is convenient to have available a means of providing
testing apparatus shall be designed so that the specimens are
variableloadsthatmaydifferfromtesttotest,dependingontheproperties
of the joint specimens and test conditions. Hollow pipe nipples containing isolated from vibration. In addition, precautions shall be taken
lead shot and sealed with end caps provide convenient deadweights. The
to avoid vibration caused by the falling deadweights at
mass of the deadweights is adjusted by adding or removing lead shot.
specimen failure. Caution shall be exercised during testing to
avoid vibration due to normal laboratory activities such as
6.4 Load Application Mechanism—This device allows for
placing all of the joint specimens under load simultaneously. opening and closing doors and bench drawers.
An example of such a device is a large tray, suspended on
NOTE 6—A wire cord, attached to the deadweight and also upper
pulleys, which supports the loads attached to the bottom of the
specimen clamp, minimizes vibration at specimen failure.The cord length
specimens. Lowering the tray allows all test specimens and
mustbelongenoughtoallowfreefallofthedeadweight,butshortenough
deadweights attached to them to be suspended freely at once. to prevent it from striking the floor of the test chamber.
D5405 – 98 (2004)
FIG. 3 Configuration and Dimensions of a T-Peel Specimen
preparation includes additional materials such as primers or
sealants is permissible. When adhesives are used, control the
thickness to 620 % of the value selected for the test specimens
(see8.1.5).Labeleachspecimenwithanidentificationnumber.
8.1.3 Lap-Shear Specimens—Prepare lap-shear test speci-
mens, 150 by 25 mm. (6 by 1 in.), 62 %, as shown in Fig. 4.
The length of the bonded lap shall be 25 mm (1 in.) 62%.If
specimens having dimensions other than those specified are
tested, they shall be described in the test report. The sheet
surface preparation and bond formation shall be as given in
8.1.2. Label each specimen with an identification number.
8.1.4 Specimen Cure—The temperature and relative humid-
ity conditions under which the test specimens are prepared and
cured shall be selected by the experimenter and described in
the test report. The temperature and relative humidity shall be
FIG. 2 Schematic of a Lap-Shear Specimen Clamped Under Load
maintained within 63°C (65°F) and 65 % relative humidity
of the selected values, respectively.
8. Test Specimens 8.1.5 Adhesive Thickness—When a liquid-based adhesive
or tape is used for bond formation, measure the dry-film
8.1 Laboratory Specimens:
adhesiveortapethicknessofeachspecimenusingaconvenient
8.1.1 The time-to-failure tests are conducted on either
laboratory method. Describe the measurement method in the
T-peelorlap-shearspecimens.Testspecimenvariablesthatcan
test report.
affect time-to-failure include, depending on the seam fabrica-
tion technique, the method of membrane material surface
NOTE 7—One method for controlling the thickness of the liquid-based
preparation, adhesive thickness, adhesive open time, pressure adhesive layer is to use a drawdown bar or similar device during
application of the adhesive to the membrane sheet. Another method is to
applied during bond formation, thermal weld temperature, and
apply the wet liquid-based adhesive to the membrane sheet at a coverage
weld equipment speed. Other variables that can affect time-to-
quantity based on the solids content of the adhesive. In such cases,
failure are time, temperature, and relative humidity of the
measurements should be performed to establish the thickness-coverage
specimen cure.
relation; if necessary, consult with the membrane manufacturer for
8.1.2 T-Peel Specimens—Prepare T-peel test specimens,
assistance in determining coverage quantities that will provide specific
125 by 25 mm (5 by 1 in.), 62 %, as shown in Fig. 3. The
adhesive thicknesses.
length of the bond shall be 75 mm (3 in.) 62 %. The test
8.2 Field Specimens:
specimens may be cut from a single section prepared by
bonding two large pieces of sheet membrane material. If
specimens having dimensions other than those specified are
tested, they shall be described in the test report. Prior to bond
formation, prepare the surface of the sheet material according
to the membrane manufacturer’s instructions, or using other
methods that shall be described in the test report. Similarly,
formthejointusingaprocess(thatis,adhesivetape,orthermal
or solvent weld) in accordance with the membrane manufac-
turer’s instructions, or using other methods that shall be
described in the test report. The use of test specimens whose FIG. 4 Configuration and Dimensions of a Lap-Shear Specimen
D5405 – 98 (2004)
creep-rupture life of the joint specimen.
8.2.1 T-peel or lap-shear specimens, having the dimensions
given in Figs. 1 and 2, respectively, may be prepared from
11. Procedure
seams sampled from roofs in service. If the specimens have
11.1 Place the specimens in the upper clamps of the
dimensions other than those given in Figs. 1 and 2, the
chamber by gripping 25 mm (1 in.), 610 %, of the free
specimen dimensions shall be given in the test report. In the
(unadhered) specimen end. Take care to avoid eccentric load-
case of lap-shear specimens, when the length of the bond is
ing of the specimen.
greater than that given in Fig. 2, precautions must be taken to
11.2 Attach the lower clamps and selected loads to the
select sufficiently high deadloads so that failure will occur in a
specimens; grip 25 mm. (1.0 in), 610 %, of the free end of the
reasonable testing time.
specimens in the clamps. The initial distances between the
8.2.2 Record all available pertinent information, including,
clampsarethus50mm(2in.)and100mm(4in.)fortheT-peel
but not limited to, specimen age and type, type of membrane
and lap-shear specimens, respectively. Avoid pre-loading by
attachment, and location of the roof, in the test report.
preventingthedeadweightsfrombeingsuspendedprematurely.
Checktheentireassemblyofspecimenandloadingmechanism
9. Number of Test Specimens and Bond Strength
for alignment; make changes, as necessary, in the assembly
9.1 Prepare a sufficient number of specimens to conduct
until ali
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