ASTM D5884-2004a Standard Test Method for Determining Tearing Strength of Internally Reinforced Geomembranes《内增强土工薄膜撕裂强度测定的标准试验方法》.pdf

1、Designation: D 5884 04aStandard Test Method forDetermining Tearing Strength of Internally ReinforcedGeomembranes1This standard is issued under the fixed designation D 5884; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year o

2、f 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 a uniform procedure for deter-mining the tear strength of flexible geomembranes internallyr

3、einforced with a textile, using the tongue tear method.1.2 The values stated in SI units are to be regarded as thestandard. The inch-pound units given in parentheses are forinformation only.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It i

4、s 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 4354 Practice for Sampling of Geosynthetics for TestingD 4439 Terminology for Ge

5、osyntheticsD 4533 Test Method for Trapezoid Tearing Strength ofGeotextiles3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 atmosphere for testing geosynthetics, nair main-tained at a relative humidity between 50 to 70 % and atemperature of 21 6 2C (70 6 4F). (See TerminologyD 4

6、439.)3.1.2 geomembrane, nan essentially impermeable geo-synthetic composed of one or more synthetic sheets. (SeeTerminology D 4439.)3.1.3 reinforced geomembranea geomembrane internallyreinforced with a textile.3.1.4 tearing strength, (F, (F), kN), nthe force requiredeither to start or to continue or

7、 propagate a tear in a fabricunder specified conditions. (See Terminology D 4439 and TestMethod D 4533.)4. Summary of Test Method4.1 The tensile tear strength of a membrane in both machineand cross-machine directions is determined by measuring themaximum load when cut specimens of specific dimension

8、s aretested to failure, by tearing, at a fixed testing displacement rate.5. Significance and Use5.1 Since tear resistance may be affected to a large degreeby mechanical fibering of the membrane under stress, as wellas by stress distribution, strain rate, and size of specimen, theresults obtained in

9、a tear resistance test can only be regarded asa measure of the resistance under the conditions of thatparticular test and not necessarily as having any direct relationto service value. This test method measures the force requiredto tear a reinforced geomembrane along a reasonably definedcourse such

10、as that the tear propagates across the width of thespecimen. The values may vary between types of reinforce-ment used within a geomembrane.5.2 The tongue tear method is useful for estimating therelative tear resistance of different reinforcing textiles ordifferent directions in the same reinforcing

11、textiles.5.3 DisputesIn case of a dispute arising from differencesin reported test results when using this test method foracceptance testing of commercial shipments, the purchaser andthe supplier should conduct comparative tests to determine ifthere is a statistical difference between their laborato

12、ries.6. Apparatus6.1 The machine shall consist of three main parts:6.1.1 Straining MechanismA machine wherein the speci-men is held between the two clamps and strained by a uniformmovement of the pulling clamp shall be used. Unless otherwisespecified in the material specification, the machine shall

13、beadjusted so that the pulling clamp shall have a uniform speedof 50 6 2 mm/min (2 6 0.1 in./min).1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.10 on Geomem-branes.Current edition approved June 1, 2004. Publishe

14、d July 2004. Originally approvedin 1995. Last previous edition approved in 2004 as D588404.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact Customer Service at serviceastm.org. For Annual Book of ASTM Stan-dardsvolume information, refer to the standards Document Summar

15、y page on theASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.1.2 Clamps for Holding SpecimenThe clamps for hold-ing a reinforced flexible geomembrane specimen shall havemetallic gripping surfaces sufficiently smooth, f

16、lat, and parallelas to prevent the test specimen from slipping or movingbetween the gripping surfaces when held under the pressurenormal to operation. The dimension of all gripping surfacesshall measure 25 by 50 mm (1 by 2 in.) or more with the longdimension perpendicular to this direction of applic

17、ation of theload. All edges that might cause a cutting action shall berounded to a radius of not over 0.4 mm (164 in.). The design ofthe clamp shall be such that one gripping surface shall be anintegral part of the rigid frame of the clamp while the othershall be on a part hinged or swiveled to the

18、movable memberof the clamp. The pressure between the gripping surfaces,sufficient to clamp the specimen firmly before testing load isapplied and to prevent slippage during the progress of the test,shall be secured by any suitably constructed mechanical deviceoperating on the movable member of the cl

19、amp. The distancebetween the clamps at the start of the test shall be 75 mm (3in.).6.1.3 Load and Elongation Recording Mechanism(s)Calibrated dial, scale, or chart to indicate applied load andelongation. Unless otherwise specified for load determination,the machine shall be adjusted or set so that t

20、he load required totear the specimen will remain indicated on the calibrated dial orscale after the test specimen has ruptured.6.2 CapacityMachine shall be of such capacity that themaximum load required to break the specimen shall not begreater than 85 % or less than 15 % of the rated capacity.6.3 T

21、esting Machine AccuracyThe error of the machineshall not exceed 2 % up to and including a 200-N (50-lbf) forceand 1 % over 200 N and 1 % at any reading within its loadingrange.NOTE 1As a practical method of determining the degree of width andalignment (in parallel) of the assembled clamp mechanism,

22、it is recom-mended that a sheet of this white paper, between two thin sheets of carbonpaper, be placed between the gripping surfaces, and the jaws then broughttogether with a light pressure.7. Test Specimen7.1 Obtain samples for specimen removal from thegeomembranes in accordance with Practice D 435

23、4.7.2 Each specimen shall be a square of 200 by 200-mm (8by 8-in.) internally reinforced geomembrane (see Fig. 1). Twosets of five specimens each will be required, one set for themachine and one set for cross-machine directions shall betested. No two specimens for machine direction tests shallcontai

24、n the same warp yarns or fibers, nor shall any twospecimens for the cross-machine tests contain the same fillingyarns or fibers. Using a precision template, a 75-mm (3-in.) cutshall be made at the center of the specimen forming the tonguesor cut strips as shown in Fig. 1.8. Conditioning8.1 Condition

25、ingCondition the test specimens at 21 62C (70 6 4F) and 50 to 70 % relative humidity for not lessthan 40 h prior to test. In cases of disagreement, the tolerancesshall be 61C (61.8F) and 62 % relative humidity.8.2 Test ConditionsConduct tests in a standard laboratoryatmosphere in accordance with Ter

26、minology D 4439, that callsfor air maintained at a relative humidity between 50 to 70 %and a temperature of 21 6 2C (70 6 4F).8.3 Moisture EquilibriumIt shall be considered that mois-ture equilibrium is reached when, after free exposure to air inmotion, there is no progressive increase in weight. Mo

27、istureequilibrium shall be approached from the dry side (notmoisture-free).NOTE 1Testing for the machine direction and cross direction tears themachine direction and cross direction fibers, respectively. (The crossdirection test tears in the machine direction).FIG. 1 Tongue Tear SpecimenD 5884 04a29

28、. Procedure9.1 Center the specimen in the machine with one tongue orcut strip centered in each clamp. Use a grip separation of 75mm (3 in.). This puts the grip faces 38 mm (112 in.) from theconverging end of the 75-mm (3-in.) cut (see Fig. 2).9.2 Start the machine and observe by means of an auto-gra

29、phic recording device the force necessary to tear thespecimen a distance of 75 to 100 mm (3 to 4 in.).9.3 If a specimen breaks or tears in a direction other thanthat of the original cut, or if for any reason attributable to faultytechnique, an individual measurement falls 25 % below orabove the aver

30、age test result for the sample unit, discard andtest another specimen.10. Interpretation of Results10.1 The tearing strength of the test specimen shall be thepeak load of resistance registered during the separation of thetear. The tearing strength of the sample unit shall be theaverage of the result

31、s obtained from five specimens tested ineach of the machine and cross-machine directions.11. Report11.1 Report the following information:11.1.1 State that the specimens were tested in accordancewith this test method and list any variations from this testmethod,11.1.2 Date of test,11.1.3 Printed name

32、 of individual performing the test,11.1.4 Test temperature and relative humidity,11.1.5 Identify the material tested, including date of manu-facture, if known,11.1.6 Average of the maximum tearing strength of speci-mens tested in each of the machine and cross-machine direc-tions, reported, N (lbf),1

33、1.1.7 Coefficient of variation of the observed tearingstrength of individual specimens, if required, and11.1.8 All observations and recorded data on which theresults are based.12. Precision and Bias12.1 PrecisionAn interlaboratory test program will beperformed to determine precision for this test me

34、thod.12.2 BiasThis test method has no bias since the values ofthese properties can be defined only in terms of a test method.13. Keywords13.1 geomembrane; reinforced; tearing strength; textileFIG. 2 Location of ClampsD 5884 04a3ASTM International takes no position respecting the validity of any pate

35、nt rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision

36、at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comme

37、nts will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted

38、 by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 5884 04a4