1、Designation: D7179 07 (Reapproved 2013)Standard Test Method forDetermining Geonet Breaking Force1This standard is issued under the fixed designation D7179; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method is used to measure the breaking forceof a Geonet.1.2 This test is applicable for manufacturing quality control(MQC)
3、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 not purport to address all of thesafety concerns, if any, assoc
4、iated 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 Standards:2D4354 Practice for Sampling of Geosynthetics and RolledEro
5、sion Control Products(RECPs) for TestingD4439 Terminology for Geosynthetics3. Terminology3.1 Definitions:3.1.1 Definitions of terms applying to this test methodappear in Terminology D4439.3.1.2 atmosphere for testing geosynthetics, nair main-tained at a relative humidity between 50 to 70 % and atemp
6、erature of 21 6 2C (70 6 4F).3.1.3 geonet, na geosynthetic consisting of integrallyconnected parallel sets of ribs overlying similar sets at variousangles for planar drainage of liquids or gases.3.1.4 index test, na test procedure which may contain aknown bias but which may be used to establish an o
7、rder for aset of specimens with respect to the property of interest.3.1.5 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 at a constant rat
8、e 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 the machine dir
9、ection 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 SpecificationD76. The load cell shall b
10、e 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 and the clamp su
11、rfaces 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.6.3 Recording MechanismThe testing machine shall beequipped with equipment capable of producing a hard copy ofthe force versus displacement curve. El
12、ectronic data acquisi-tion with printer capabilities or direct recording devices isacceptable.7. Sampling, Test Specimens, and Test Units7.1 Lot SampleFor the lot sample, take rolls of geonet perthe applicable project specification, or as agreed upon betweenpurchaser and supplier. Unless otherwise s
13、pecified, refer toPractice D4354.1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.01 on Mechani-cal Properties.Current edition approved Jan. 1, 2013. Published January 2013. Originallyapproved in 2005. Last previou
14、s edition approved in 2007 as D717907. DOI:10.1520/D7179-07R13.2For 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 websit
15、e.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States17.2 Laboratory SampleFor laboratory sample, take a full-width swatch approximately1m(3ft)long by roll width foreach roll in the lot sample. Take a sample that will excludematerial from
16、 the outer wrap 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 Specimens Prepare five specimens with the lengthof the specimen parallel to the machine direction (MD). Cut t
17、hespecimens such 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 froma
18、cross the width 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 specime
19、ns can be tested at the clientsrequest but they are not a requirement.8. Conditioning8.1 Conditioning Specimens may be tested once theyhave equilibrated at standard laboratory temperature. The timerequired to reach temperature equilibrium may vary accordingto the manufacturing process, material type
20、 and materialthickness. 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 Conditions Conduct tests at the standard atmo-sphere for testing geosynthetics, a temperature of 21 6 2C (706 4F) and a
21、 relative humidity 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.
22、 This is a critical 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, o
23、r if for any reason 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 Re
24、peat the procedure 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
25、 is, MD),11.1.3 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 anInterlabo
26、ratory study of D7179-05, 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 Repeatabilit
27、y Two test results 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
28、the same day in the same laboratory. SeeTable 112.1.2 Reproducibility Two 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 oper
29、ators using different 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 test
30、method, therefore no statement on bias is being made.12.3 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 involved.13. Keywords13.1
31、 break; force; geonet; geosynthetic; index test; machinedirection; tensile3Supporting 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 RepeatabilityStandardDeviationReproducibilit
32、yStandardDeviationRepeatabilityLimitReproducibilityLimitxSr sR r RGeonet“A”291.9 8.8 23.2 24.6 64.8D7179 07 (2013)2ASTM 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 ad
33、vised 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 at any time by the responsible technical committee and must be reviewed every five years andif not revised, eithe
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35、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 by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Indiv
36、idual 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D7179 07 (2013)3
