1、Designation: D7179 18Standard 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. A number in parent
2、heses 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) and construction q
3、uality 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, associated with its us
4、e. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principle
5、s on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D76/D76M Specification for Tensile T
6、esting Machines forTextilesD4354 Practice for Sampling of Geosynthetics and RolledErosion 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 testi
7、ng geosynthetics, nair main-tained at a relative humidity between 50 to 70 % and atemperature of 21 6 2 C (70 6 4 F).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,
8、 na test procedure which may contain aknown bias but which may be used to establish an order 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 grips
9、in a load frame. Tensile load is applied longitudinally to thespecimen at 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 o
10、f quality control and quality assurance.Testing is performed parallel to the machine direction only, forthat is the primary direction that geonets witness tensileloading. This method is an index test and is not intended fordesign purposes.6. Apparatus6.1 Tensile Testing MachineConstant rate of exten
11、sion(CRE) equipment meeting the requirements of SpecificationD76/D76M. The load cell shall be accurate to within 61%ofthe applied force. The drive mechanism shall be able to controlthe rate of extension to within 61 % of the targeted rate.6.2 GripsOne of the grips must be self-aligning to com-pensat
12、e for uneven distribution of force across the specimen.The clamping force 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.6.3 Recording MechanismThe testing machine shall beequipped
13、 with equipment capable of producing a hard copy of1This 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 July 1, 2018. Published July 2018. Originally approvedin 200
14、5. Last previous edition approved in 2013 as D7179 07 (2013). DOI:10.1520/D7179-18.2For 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 pa
15、ge onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for t
16、heDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1the force-versus-displacement curve. Electronic data acquisi-tion with printer capabilities or direct recording devices isacceptable.7. Sampling, T
17、est 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 specified, refer toPractice D4354.7.2 Laboratory SampleFor laboratory sample, take a full-width swatch approx
18、imately1m(3ft)long by roll width foreach roll in the lot sample. Take a sample that will excludematerial from 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
19、SpecimensPrepare five specimens with the lengthof the specimen parallel to the machine direction (MD). Cut thespecimens such that none is obtained within 150 mm (6 in.) ofthe 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 d
20、irection). Die-cut test specimens are recommended.7.5 Test UnitTest five specimens distributed evenly fromacross the width of each laboratory sample in the longitudinal(machine) direction only. It may be desirable to test specimensin the transverse (cross-machine) direction for special pur-poses.NOT
21、E 1Depending on the application/installation of geonets, trans-verse (cross-machine) direction specimens can be tested at the clientsrequest, but they are not a requirement.8. Conditioning8.1 ConditioningSpecimens may be tested once they haveequilibrated at standard laboratory temperature. The timer
22、equired to reach temperature equilibrium may vary accordingto the manufacturing process, material type, 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 ConditionsConduc
23、t tests at the standard atmo-sphere for testing geosynthetics, a temperature of 21 6 2C(70 6 4 F) and a 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
24、centered in both sets ofclamps and aligned vertically about the centroid of the tensiletesting machine. This is a critical point, since the breakingforce is 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
25、 ruptured. If the specimenslips in the clamps, breaks in the clamps, breaks at the edges ofthe clamps, or if for any reason attributable to faulty operationthe result falls markedly below the average (outliers are definedas greater than 20 % from the mean) for the set of specimens,discard the result
26、 and test an additional specimen.9.4 Record peak load. The peak load is the geonet breakingforce.9.5 Repeat the procedure for the remaining specimens.10. Calculation10.1 Calculate the tensile strength of individual specimens;that is, the maximum tensile breaking force per unit widthexpressed in N/m
27、(lbf/in.), using Eq 1, as follows:f5 Ff Ws(1)where:f= tensile strength per unit width, N/m (lbf/in.),Ff= observed breaking force, N (lbf), andWs= specimen width, m (in.).11. Report11.1 Report the following information:11.1.1 Complete identification of the material tested,11.1.2 The direction of test
28、ing (that is, MD),11.1.3 The breaking force per unit width of each specimentested in units of N/m (lbf/in.),11.1.4 Any deviation of the specified test procedure, and11.1.5 The average and standard deviation for breakingforce per unit width in units of N/m (lbf/in.).12. Precision and Bias312.1 The pr
29、ecision of this test method is based on anInterlaboratory study of D717905, 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
30、 test results for the material.12.1.1 RepeatabilityTwo 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
31、 by the same operator using thesame equipment on the same day in the same laboratory. SeeTable 1.12.1.2 ReproducibilityTwo test results should be judgednot equivalent if they differ by more than the “R” value for that3Supporting data have been filed at ASTM International Headquarters and maybe obtai
32、ned by requesting Research Report RR:D35-1011. ContactASTM CustomerService at serviceastm.org.TABLE 1 Tensile Strength (in pounds)MaterialAveragexRepeatabilityStandardDeviationSrReproducibilityStandardDeviationsRRepeatabilityLimitrReproducibilityLimitRGeonet“A”291.9 8.8 23.2 24.6 64.8D7179 182materi
33、al; “R” is the interval representing the difference be-tween two test results for the same material, obtained bydifferent operators 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 beingcor
34、rect.12.2 BiasAt the time of the study, there was no acceptedreference material suitable for determining the bias for this testmethod; 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, ono
35、ne material.12.4 This precision statement is provisional because aninsufficient number of materials was involved.13. Keywords13.1 break; force; geonet; geosynthetic; index test; machinedirection; tensileASTM International takes no position respecting the validity of any patent rights asserted in con
36、nection 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 at any time by the respon
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38、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 by ASTM International, 1
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