ASTM D7004-2003 Standard Test Method for Grab Tensile Properties of Reinforced Geomembranes《增强土工薄膜的咬合张力性能的标准试验方法》.pdf

1、Designation: D 7004 03Standard Test Method forGrab Tensile Properties of Reinforced Geomembranes1This standard is issued under the fixed designation D 7004; 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method is used to measure the grab tensileproperties of reinforced geomembranes.1.2 The values stated in SI units are to

3、be regarded asstandard. The values given in parentheses are for informationonly.1.3 This standard does not 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 det

4、ermine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:D 76 Specification for Tensile Testing Machines for TextilesD 4354 Practice for Sampling of GeosyntheticsD 4439 Terminology for Geosynthetics3. Terminology3.1 DefinitionsDefinitions of terms ap

5、plying 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 reinforced geomembrane, na geomembrane inter-nally reinforced with a textile.3.1.3 yarn, na generi

6、c term for a continuous strand oftextile fibers, filaments or material in a form suitable forknitting, weaving or otherwise intertwining to form a textilefabric.4. Significance and Use4.1 This method evaluates grab tensile properties of rein-forced geomembranes for the purposes of quality control,qu

7、ality assurance and research. In order to evaluate the fullcontribution of the reinforcement, testing is performed parallelto the directions of reinforcement. This method is an index testand is not intended for design purposes.5. Apparatus5.1 Tensile Testing MachineConstant Rate of Extension(CRE) eq

8、uipment meeting the requirements of SpecificationD 76. The 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.5.2 GripsOne of the grips must be self aligning tocompensate for uneven dis

9、tribution of force across the speci-men. The clamping force and the clamp surfaces shall hold thespecimen firmly without causing damage. The clamps shall becapable of gripping a 25 mm (1 in.) by 25 mm (1 in.) area. Thiscan be accomplished by either using 25 mm (1 in.) squareclamp faces or by using c

10、lamps with dimensions of 25 mm (1in.) by greater than 25 mm (1 in.) and crossing the clamps inthe grips so that only a 25 mm (1 in.) by 25 mm (1 in.) area isgripped.5.3 Recording MechanismThe testing machine shall beequipped with equipment capable of producing a hard copy ofthe force versus displace

11、ment curve. Electronic data acquisi-tion with printer capabilities or direct recording devices areacceptable.6. Sampling and Test Specs and Units6.1 Lot SampleFor the lot sample, take rolls of geomem-brane per the applicable project specification, or as agreedupon between purchaser and supplier. Unl

12、ess otherwise speci-fied, refer to Practice D 4354.6.2 Laboratory SampleFor the 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 wrap of the roll or the inner wraparound the core.

13、In the case where the sample is taken at theproduction site, material from the outer wrap may be used if itis undamaged.6.3 Test SpecimensPrepare five specimens with the lengthof the specimen parallel to the machine direction (MD) and fivespecimens with the length parallel to the transverse directio

14、n(TD) for materials with the reinforcement running in thosedirections. If the reinforcement is aligned in any direction otherthan the machine or transverse directions, specimens shall becut parallel to those directions and so noted in the report. Cutthe specimens such that different reinforcing yarn

15、s or strands1This 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 Dec. 1, 2003. Published January 2004.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West

16、 Conshohocken, PA 19428-2959, United States.are tested in each specimen. Specimens may be taken from theselvage as long as there are not more yarns in the selvage thanin the rest of the product.6.4 The specimens shall be 100 mm (4 in.) wide by at least150 mm (6 in.) long (test direction). Test speci

17、mens shall be cutparallel to the direction of reinforcement being tested.7. Conditioning7.1 ConditioningSpecimens may be tested once they haveequilibrated at standard laboratory temperature. The timerequired to reach temperature equilibrium may vary accordingto the manufacturing process, material ty

18、pe and materialthickness.7.2 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.8. Procedure8.1 Set the distance between the gripping portion of theclamps 75 mm (3

19、 in.) apart.8.2 Clamp a specimen so that the same strands of reinforce-ment are gripped by both sets of clamps with the sides of theclamps being parallel to the tested reinforcement. This is acritical point since the tensile strength is significantly reducedif the scrim is not properly aligned in th

20、e grips.8.3 Elongate the specimen at a test speed of 300 mm/min(12 in./min) until both the reinforcement and the polymericfilm or sheet has failed, recording the load-extension curve. Ifthe specimen slips in the clamps, breaks in the clamps, breaksat the edges of the clamps, the scrim pulls out and

21、does notbreak, or if for any reason attributable to faulty operation, theresult falls markedly below the average for the set of speci-mens, discard the result and test an additional specimen.8.4 Record peak load and separation at peak load.8.5 Repeat the procedure for the remaining specimens.9. Calc

22、ulation9.1 Calculate elongation by dividing the grip movement by75 mm (3 in.), multiplying by 100 % and reporting in percent.9.2 Calculate the average and standard deviation for peakstrength and elongation at peak strength. Calculate the resultsfor each test direction separately.10. Report10.1 Repor

23、t the following information:10.1.1 Complete identification of the material tested,10.1.2 The direction of testing if other than MD and TD,10.1.3 Any deviation of the specified test procedure, and10.1.4 The average and standard deviation for peak strengthin units of kN (lb) and percent elongation at

24、peak strength.Report each test direction results separately.11. Precision and Bias11.1 No precision and bias has been established yet for thistest standard.12. Keywords12.1 geomembrane; grab tensile; reinforced; tensileASTM International takes no position respecting the validity of any patent rights

25、 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 at any ti

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27、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 by ASTM

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