ASTM D7179-2005 Standard Test Method for Determining Geonet Breaking Force《测定土工网断裂力的标准试验方法》.pdf

1、Designation: D 7179 05Standard 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 pare

2、ntheses 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 is used to measure the breaking forceof a Geonet.1.2 This test is applicable for manufacturing quality control(MQC) and constructio

3、n 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, associated with its

4、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:2D 4354 Practice for Sampling of GeosyntheticsD 4439 Terminology for Geosy

5、nthetics3. 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 to 70 % and atemperature of 21 6 2C (70 6 4F).3.1.2 geonet, na geosynthetic consisting of

6、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 to establish an order for aset of specimens with respect to the property of interest.3.1.4

7、 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 rate of crosshead movement. The test iscarried to rupture and a maximum brea

8、king 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 direction only forthat is the primary direction that geonets witnesses tensi

9、leloading. 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 load cell shall be accurate to within 61 % of theapplied force. The drive mechanism shall

10、 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 surfaces shall hold thespecimen firmly without causing damage. The clamps

11、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. Electronic data acquisi-tion with printer capabilities or direct recording

12、 devices isacceptable.7. Sampling and Test Specs and 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 D 4354.1This test method is under the jurisdiction o

13、f ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.01 on Mechani-cal Properties of Geosynthetics.Current edition approved June 1, 2005. Published July 2005.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at

14、serviceastm.org. For 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.7.2 Laboratory SampleFor laboratory sample, take af

15、ull-width swatch approximately1m(3ft)long by roll widthfor each 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 i

16、tis undamaged.7.3 Test SpecimensPrepare five specimens with the lengthof the specimen parallel to the machine direction (MD). Cut thespecimens 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(

17、86 0.16 in.)long (test direction). 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 in the transverse (cross-machine) dire

18、ction for specialpurposes.NOTE 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 labor

19、atory temperature. The timerequired 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 hou

20、r.8.2 Test ConditionsConduct tests at the standard atmo-sphere for testing geosynthetics, a temperature of 21 6 2C (706 4F) 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

21、 a specimen so that it is centered in both sets ofclamps and aligned vertically about the centroid of the tensiletesting machine. 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./mi

22、n) 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 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 sp

23、ecimens,discard the result 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 average and standard deviation for break-ing force of the five specimens tested.11. Report

24、11.1 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 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 devi

25、ation for breakingforce in units of kN (lb).12. Precision and Bias12.1 No precision and bias has been established yet for thistest standard.13. Keywords13.1 break; force; geonet; geosynthetic; index test; machinedirection; tensileASTM International takes no position respecting the validity of any pa

26、tent 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 revisio

27、n 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 com

28、ments 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 copyright

29、ed 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).D7179052