1、Designation: D 5405 98 (Reapproved 2004)Standard Test Method forConducting Time-to-Failure (Creep-Rupture) Tests of JointsFabricated from Nonbituminous Organic Roof MembraneMaterial1This standard is issued under the fixed designation D 5405; the number immediately following the designation indicates
2、 the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers laboratory determinati
3、on of thetime-to-failure (creep-rupture) of joints fabricated from nonbi-tuminous organic roof membrane material. The test methodcovers both T-peel and lap-shear joints subjected to constanttensile load under controlled environmental conditions. Thejoints, made from either unreinforced or fabric-rei
4、nforcedmembrane material, are prepared in the laboratory or sampledfrom roofs in service.1.2 Sheet materials from which the joints are fabricatedinclude vulcanized rubbers, nonvulcanized polymeric sheets,and thermoplastics. The bonding methods for joint formationinclude the use of liquid-based adhes
5、ives, preformed tapes, andthermal and solvent weld processes.1.3 The values stated in S.I. units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is
6、theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 816 Test Methods for Rubber CementsD 907 Terminology of AdhesivesD 1079 Terminolog
7、y Relating to Roofing, Waterproofing,and Bituminous MaterialsD 1876 Test Method for Peel Resistance of Adhesives(T-Peel Test)3. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, refer to Terminology D 907 and D 1079.3.2 Definitions of Terms Specific to This Standard:3.2.1 c
8、reep-rupture testa test that measures the time-to-failure of a specimen subjected to a constant load; progressivespecimen deformation may also be measured.3.2.2 failurerupture of the bond resulting in completeseparation of its adherends under the test conditions; or,alternatively, rupture of the mem
9、brane material away from thebonded section of the test specimen (that is, material rupture).3.2.3 time-to-failurethe period of time beginning when ajoint specimen is placed under load and ending when failureoccurs.4. Summary of Test Method4.1 This test method is a creep-rupture test without mea-sure
10、ment of specimen deformation. The time-to-failure, inhours, of joints fabricated from nonbituminous organic roofmembrane materials is measured when subject to constantdeadweight loads under controlled temperature and humidityconditions.5. Significance and Use5.1 An important factor affecting the per
11、formance of jointsof nonbituminous membranes is their ability to remain bondedover the membranes expected service life. Time-to-failuretests provide a means of characterizing the behavior of jointsunder constant load over time.5.2 Creep is a sensitive index of rheological properties thatdepend on ma
12、terial, load, temperature, and time. Time-to-failure data that are obtained over a relatively short time periodcan evaluate one factor affecting a joints ability to withstandstatic loading over a relatively long time period.5.3 Time-to-failure data for joints of nonbituminous organicroof membrane sp
13、ecimens can be used for the following: (1)toprovide a measure of the load-carrying ability of the joint as afunction of time at various levels of load, temperature, andrelative humidity; (2) to characterize the joint with regard tofactors affecting performance, such as surface preparation of1This te
14、st method is under the jurisdiction of ASTM Committee D08 on Roofingand Waterproofing and is the direct responsibility of Subcommittee D08.18 onNonbituminous Organic Roof Coverings.Current edition approved July 1, 2004. Published July 2004. Originally approvedin 1993. Last previous edition approved
15、in 1998 as D 5405 98.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr
16、Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.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 theeffects of different bonding processes or adh
17、esive bondingmaterials on joint performance.5.4 While it is considered that the results obtained by thislaboratory test may afford a measure of the performance ofseams in service, provided that load, temperature, and humidityconditions are known, no direct correlation has been estab-lished.6. Appara
18、tus6.1 Test Chamber, of sufficient size to hold a minimum of15 specimens. The height of the chamber shall be sufficient toallow suspension of the deadweight loads and specimendeformation during testing. The chamber shall be structurallycapable of supporting the loads anticipated during testingwithou
19、t appreciable deflection.NOTE 1A minimum height of 600 mm (24 in.) is suitable for thespecimen sizes described in this test method if they are not extremelyextensible. A taller chamber may be needed if they are extremelyextensible.6.1.1 Temperature and Humidity ControlThe control oftemperature and h
20、umidity is important, since small changes inthese variables may produce large changes in time-to-failure.The temperature and relative humidity within the chambershall be controlled within 63C (6 5F) and 65 % relativehumidity, respectively, over the duration of the test. Anydeviations from these limi
21、ts shall be given in the test report.The selected temperature and humidity conditions shall beuniform throughout the enclosed space (63C or 65F and65 % relative humidity). If this uniformity is achieved throughmechanical air circulation, it shall not cause the specimens tosway, vibrate, or be otherw
22、ise disturbed.NOTE 2Suggested test conditions are as follows: (1) normal ambienttemperature (approximately 23C or 73F) and humidity (50 % relativehumidity); and (2) extremes to which the seams may be subjected inservice.6.2 Specimen and Load ClampingThe chamber shall beequipped with a means for clam
23、ping the joint specimensvertically to the top of the interior of the chamber, or othersuitable upper support. Also, a clamp shall be provided tosecure the deadweight loads to the bottom of the jointspecimens. Figs. 1 and 2 show a suggested clamping arrange-ment including the deadweight load.6.3 Dead
24、weight Loads, of appropriate mass (see Section10).NOTE 3It is convenient to have available a means of providingvariable loads that may differ from test to test, depending on the propertiesof the joint specimens and test conditions. Hollow pipe nipples containinglead shot and sealed with end caps pro
25、vide convenient deadweights. Themass of the deadweights is adjusted by adding or removing lead shot.6.4 Load Application MechanismThis device allows forplacing all of the joint specimens under load simultaneously.An example of such a device is a large tray, suspended onpulleys, which supports the lo
26、ads attached to the bottom of thespecimens. Lowering the tray allows all test specimens anddeadweights attached to them to be suspended freely at once.NOTE 4If each specimen has its own timer device (see 6.5), it is notnecessary to load all specimens simultaneously.6.5 Timer Device, for recording th
27、e total time over whicheach individual specimen is under load, or for marking the timeat which failure of each specimen occurs. The sensitivity of thetimer shall be as follows:Failure Time Timer Sensitivity#25 h 0.1 min25 and #100 h 0.01 h100 h 0.1 hNOTE 5For investigations involving multiple specim
28、ens in the cham-ber, a computer-controlled timer that records the time-to-failure has beenfound to be satisfactory. In this case, a micro-electrical circuit connectedto the computer is set up for each specimen. The circuit consists of a wireloop, of which one segment is a short length of wire (trigg
29、er wire) attachedto each grip on the test specimen and set to stop the computer clock whenfailure occurs. At the point of attachment at the top grip, the trigger wireis inserted in an electrical connector. When the specimen fails and thedeadweight on the lower grip falls, the trigger wire is pulled
30、from theconnector, breaking the circuit and stopping the clock.7. Vibration Control7.1 Because the time-to-failure tests are sensitive to vibra-tion, select a location of the testing apparatus for minimumdisturbance. When a vibration-free location is not available, thetesting apparatus shall be desi
31、gned so that the specimens areisolated from vibration. In addition, precautions shall be takento avoid vibration caused by the falling deadweights atspecimen failure. Caution shall be exercised during testing toavoid vibration due to normal laboratory activities such asopening and closing doors and
32、bench drawers.NOTE 6A wire cord, attached to the deadweight and also upperspecimen clamp, minimizes vibration at specimen failure. The cord lengthmust be long enough to allow free fall of the deadweight, but short enoughto prevent it from striking the floor of the test chamber.FIG. 1 Schematic of a
33、T-Peel Specimen Clamped Under LoadD 5405 98 (2004)28. Test Specimens8.1 Laboratory Specimens:8.1.1 The time-to-failure tests are conducted on eitherT-peel or lap-shear specimens. Test specimen variables that canaffect time-to-failure include, depending on the seam fabrica-tion technique, the method
34、of membrane material surfacepreparation, adhesive thickness, adhesive open time, pressureapplied during bond formation, thermal weld temperature, andweld equipment speed. Other variables that can affect time-to-failure are time, temperature, and relative humidity of thespecimen cure.8.1.2 T-Peel Spe
35、cimensPrepare T-peel test specimens,125 by 25 mm (5 by 1 in.), 62 %, as shown in Fig. 3. Thelength of the bond shall be 75 mm (3 in.) 62 %. The testspecimens may be cut from a single section prepared bybonding two large pieces of sheet membrane material. Ifspecimens having dimensions other than thos
36、e specified aretested, they shall be described in the test report. Prior to bondformation, prepare the surface of the sheet material accordingto the membrane manufacturers instructions, or using othermethods that shall be described in the test report. Similarly,form the joint using a process (that i
37、s, adhesive tape, or thermalor solvent weld) in accordance with the membrane manufac-turers instructions, or using other methods that shall bedescribed in the test report. The use of test specimens whosepreparation includes additional materials such as primers orsealants is permissible. When adhesiv
38、es are used, control thethickness to 620 % of the value selected for the test specimens(see 8.1.5). Label each specimen with an identification number.8.1.3 Lap-Shear SpecimensPrepare 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
39、 25 mm (1 in.) 62%.Ifspecimens having dimensions other than those specified aretested, they shall be described in the test report. The sheetsurface preparation and bond formation shall be as given in8.1.2. Label each specimen with an identification number.8.1.4 Specimen CureThe temperature and relat
40、ive humid-ity conditions under which the test specimens are prepared andcured shall be selected by the experimenter and described inthe test report. The temperature and relative humidity shall bemaintained within 63C (65F) and 65 % relative humidityof the selected values, respectively.8.1.5 Adhesive
41、 ThicknessWhen a liquid-based adhesiveor tape is used for bond formation, measure the dry-filmadhesive or tape thickness of each specimen using a convenientlaboratory method. Describe the measurement method in thetest report.NOTE 7One method for controlling the thickness of the liquid-basedadhesive
42、layer is to use a drawdown bar or similar device duringapplication of the adhesive to the membrane sheet. Another method is toapply the wet liquid-based adhesive to the membrane sheet at a coveragequantity based on the solids content of the adhesive. In such cases,measurements should be performed to
43、 establish the thickness-coveragerelation; if necessary, consult with the membrane manufacturer forassistance in determining coverage quantities that will provide specificadhesive thicknesses.8.2 Field Specimens:FIG. 2 Schematic of a Lap-Shear Specimen Clamped Under LoadFIG. 3 Configuration and Dime
44、nsions of a T-Peel SpecimenFIG. 4 Configuration and Dimensions of a Lap-Shear SpecimenD 5405 98 (2004)38.2.1 T-peel or lap-shear specimens, having the dimensionsgiven in Figs. 1 and 2, respectively, may be prepared fromseams sampled from roofs in service. If the specimens havedimensions other than t
45、hose given in Figs. 1 and 2, thespecimen dimensions shall be given in the test report. In thecase of lap-shear specimens, when the length of the bond isgreater than that given in Fig. 2, precautions must be taken toselect sufficiently high deadloads so that failure will occur in areasonable testing
46、time.8.2.2 Record all available pertinent information, including,but not limited to, specimen age and type, type of membraneattachment, and location of the roof, in the test report.9. Number of Test Specimens and Bond Strength9.1 Prepare a sufficient number of specimens to conductboth bond strength
47、measurement and time-to-failure tests.NOTE 8A newly prepared joint may change with time due tomechanisms such as cure, solvent evaporation, or crystallization. Thisresults in a bond strength that increases with time initially and thenreaches a constant value. In such cases, it is necessary to provid
48、etime-to-failure specimens that have been cured over a time periodsufficient that their bond strength is constant. Determination of theconstant bond strength will influence the number of specimens necessaryto conduct this test method. Pretesting the bond strength of somespecimens over time is useful
49、 to estimate the time at which constantstrength is attained under the cure conditions.9.2 Test the bond strength (see 9.2.1 and 9.2.2) of sets of aminimum of three joint specimens (either T-peel or lap-shear)periodically, and plot the strength results versus time. Use aminimum of four time intervals at least one day apart. Thebond strength of the specimen shall be considered to beconstant when the slope of the bond strength-time curve doesnot differ from zero significantly.9.2.1 Peel StrengthDetermine the peel strength as de-scribed in Test Method D
