ASTM D7179-2007e1 952 Standard Test Method for Determining Geonet Breaking Force《测定土工网断裂力的标准试验方法》.pdf

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1、Designation: D 7179 07e1Standard Test Method forDetermining Geonet Breaking Force1This standard is issued under the fixed designation D 7179; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in pa

2、rentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTEAdded research report footnote to Section 12 editorially in May 2008.1. Scope1.1 This test method is used to measure the breaking forceof a Geonet.1.2 T

3、his test is applicable for manufacturing quality control(MQC) and construction quality assurance (CQA) testing andis not recommended as a performance test.1.3 The values stated in SI units are to be regarded asstandard. The values given in parentheses are for informationonly.1.4 This standard does n

4、ot purport to address all of thesafety concerns, if any, associated with its use. It is 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 Standar

5、ds:2D 4354 Practice for Sampling of Geosynthetics for TestingD 4439 Terminology for Geosynthetics3. Terminology3.1 DefinitionsDefinitions of terms applying to this testmethod appear in Terminology D 4439.3.1.1 atmosphere for testing geosynthetics, nair main-tained at a relative humidity between 50 t

6、o 70 % and atemperature of 21 6 2C (70 6 4F).3.1.2 geonet, na geosynthetic consisting of integrallyconnected parallel sets of ribs overlying similar sets at variousangles for planar drainage of liquids or gases.3.1.3 index test, na test procedure which may contain aknown bias but which may be used t

7、o establish an order for aset of specimens with respect to the property of interest.3.1.4 peak load, nmaximum force recorded during atensile test.4. Summary of Test Method4.1 Geonet specimens are mounted between full width gripsin a load frame. Tensile load is applied longitudinally to thespecimen a

8、t a constant rate of crosshead movement. The test iscarried to rupture and a maximum breaking force of eachspecimen is recorded.5. Significance and Use5.1 This method evaluates tensile breaking force of geonetsfor the purposes of quality control and quality assurance.Testing is performed parallel to

9、 the machine direction only forthat is the primary direction that geonets witnesses tensileloading. This method is an index test and is not intended fordesign purposes.6. Apparatus6.1 Tensile Testing MachineConstant Rate of Extension(CRE) equipment meeting the requirements of SpecificationD 76. The

10、load cell shall be accurate to within 61 % of theapplied force. The drive mechanism shall be able to control therate of extension to within 61 % of the targeted rate.6.2 GripsOne of the grips must be self aligning tocompensate for uneven distribution of force across the speci-men. The clamping force

11、 and the clamp surfaces shall hold thespecimen firmly without causing damage. The clamps shall becapable of gripping a 100 mm (4 in.) by 25 mm (1 in.) area ata minimum.1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D

12、35.01 on Mechani-cal Properties.Current edition approved Dec. 1, 2007. Published December 2007. Originallyapproved in 2005. Last previous edition approved in 2005 as D 717905.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For

13、 Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.3 Recording MechanismThe testing machine shall beequipped with equipm

14、ent capable of producing a hard copy ofthe force versus displacement curve. Electronic data acquisi-tion with printer capabilities or direct recording devices isacceptable.7. Sampling and Test Specs and Units7.1 Lot SampleFor the lot sample, take rolls of geonet perthe applicable project specificati

15、on, or as agreed upon betweenpurchaser and supplier. Unless otherwise specified, refer toPractice D 4354.7.2 Laboratory SampleFor laboratory sample, take afull-width swatch approximately1m(3ft)long by roll widthfor each roll in the lot sample. Take a sample that will excludematerial from the outer w

16、rap of the roll or the inner wraparound the core. In the case where the sample is taken at theproduction site, material from the outer wrap may be used if itis undamaged.7.3 Test SpecimensPrepare five specimens with the lengthof the specimen parallel to the machine direction (MD). Cut thespecimens s

17、uch that none are obtained within 150 mm (6 in.)of the roll edges.7.4 Specimen Size and ShapeThe specimens shall be 1026 2mm(46 0.08 in.) wide by 203 6 4mm(86 0.16 in.)long (test direction). Die cut test specimens are recommended.7.5 Test UnitTest five specimens distributed evenly fromacross the wid

18、th of each laboratory sample in the longitudinal(machine) direction only. It may be desirable to test specimensin the in the transverse (cross-machine) direction for specialpurposes.NOTE 1Depending on the application/installation of geonets, trans-verse (cross-machine) direction specimens can be tes

19、ted at the clientsrequest but they are not a requirement.8. Conditioning8.1 ConditioningSpecimens may be tested once they haveequilibrated at standard laboratory temperature. The timerequired to reach temperature equilibrium may vary accordingto the manufacturing process, material type and materialt

20、hickness. Equilibrium in this case is defined as less than adegree Celsius change in temperature in an hour and less thana gram change in mass within an hour.8.2 Test ConditionsConduct tests at the standard atmo-sphere for testing geosynthetics, a temperature of 21 6 2C (706 4F) and a relative humid

21、ity between 50 to 70 %, unlessotherwise specified.9. Procedure9.1 Set the distance between the gripping portions of theclamps 100 mm (4 in.) apart.9.2 Clamp a specimen so that it is centered in both sets ofclamps and aligned vertically about the centroid of the tensiletesting machine. This is a crit

22、ical point since the breaking forceis significantly altered if the specimen is not aligned.9.3 Elongate the specimen at a test speed of 300 mm/min(12 in./min) until the specimen has ruptured. If the specimenslips in the clamps, breaks in the clamps, breaks at the edges ofthe clamps, or if for any re

23、ason attributable to faulty operation,the result falls markedly below the average (outliers are definedas greater than 20 % from the mean) for the set of specimens,discard the result and test an additional specimen.9.4 Record peak load. The peak load is the geonet breakingforce.9.5 Repeat the proced

24、ure for the remaining specimens.10. Calculation10.1 Calculate the average and standard deviation for break-ing force of the five specimens tested.11. Report11.1 Report the following information:11.1.1 Complete identification of the material tested,11.1.2 The direction of testing (that is, MD),11.1.3

25、 The breaking force of each specimen tested in unitsof kN (lb),11.1.4 Any deviation of the specified test procedure, and11.1.5 The average and standard deviation for breakingforce in units of kN (lb).12. Precision and Bias312.1 The precision of this test method is based on anInterlaboratory study of

26、 D 7179-05, Standard Test Method forDetermining Geonet Breaking Force, conducted in 2006. Ninelaboratories tested one material. Each “test result” was theaverage of five individual determinations. Each laboratoryobtained three replicate test results for the material.12.1.1 RepeatabilityTwo test resu

27、lts obtained within onelaboratory shall be judged not equivalent if they differ by morethan the “r” value for that material; “r” is the intervalrepresenting the critical difference between two test results forthe same material, obtained by the same operator using thesame equipment on the same day in

28、 the same laboratory. SeeTable 112.1.2 ReproducibilityTwo test results should be judgednot equivalent if they differ by more than the “R” value for thatmaterial; “R” is the interval representing the difference be-tween two test results for the same material, obtained bydifferent operators using diff

29、erent equipment in different labo-ratories.12.1.3 Any judgment in accordance with these two state-ments would have an approximate 95% probability of beingcorrect.12.2 BiasAt the time of the study, there was no acceptedreference material suitable for determining the bias for this testmethod, therefor

30、e no statement on bias is being made.3Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: D35-1011.TABLE 1 Tensile Strength (in pounds)Material Average RepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimit

31、ReproducibilityLimitxSr sR r RGeonet“A”291.9 8.8 23.2 24.6 64.8D717907e1212.3 The precision statement was determined through sta-tistical examination of 27 results, from nine laboratories, on 1material.12.4 This precision statement is provisional because aninsufficient number of materials were invol

32、ved.13. Keywords13.1 break; force; geonet; geosynthetic; index test; machinedirection; tensileASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determinat

33、ion 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 at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withd

34、rawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your

35、 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 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).D717907e13