ASTM D4595-17 Standard Test Method for Tensile Properties of Geotextiles by the Wide-Width Strip Method.pdf

1、Designation: D4595 17Standard Test Method forTensile Properties of Geotextiles by the Wide-Width StripMethod1This standard is issued under the fixed designation D4595; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las

2、t revision. 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 covers the measurement of tensileproperties of geotextiles using a wide-width strip specimentensile meth

3、od. This test method is applicable to most geotex-tiles that include woven fabrics, nonwoven fabrics, layeredfabrics, knit fabrics, and felts that are used for geotextileapplication.1.2 This test method covers the measurement of tensilestrength and elongation of geotextiles and includes directionsfo

4、r the calculation of initial modulus, offset modulus, secantmodulus, and breaking toughness.1.3 Procedures for measuring the tensile properties of bothconditioned and wet geotextiles by the wide-width stripmethod are included.1.4 The basic distinction between this test method and othermethods for me

5、asuring strip tensile properties is the width ofthe specimen. Some fabrics used in geotextile applicationshave a tendency to contract (neck down) under a force in thegage length area. The greater width of the specimen specifiedin this test method minimizes the contraction effect of thosefabrics and

6、provides a closer relationship to expected geotextilebehavior in the field and a standard comparison.1.5 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 hea

7、lth practices and determine the applica-bility of regulatory limitations prior to use.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, G

8、uides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D76 Specification for Tensile Testing Machines for TextilesD123 Terminology Relating to TextilesD579 Specification for Greige Woven Glass FabricsD17

9、76 Practice for Conditioning and Testing TextilesD2905 Practice for Statements on Number of Specimens forTextiles (Withdrawn 2008)3D4439 Terminology for Geosynthetics3. Terminology3.1 atmosphere for testing geotextiles, nair maintained ata relative humidity of 65 6 5 % and a temperature of 21 62 C (

10、70 6 4 F).3.2 breaking toughness, T, (FL1), Jm2, nfor geotextiles,the actual work-to-break per unit surface area of material.3.2.1 DiscussionBreaking toughness is proportional to thearea under the force-elongation curve from the origin to thebreaking point (see also work-to-break). Breaking toughnes

11、s iscalculated from work-to-break, gage length, and width of aspecimen.3.3 corresponding force, Fc,nthe force associated with aspecific elongation on the force-per-unit-width strain curve.(Syn. load at specified elongation, LASE.)3.4 geotechnical engineering, nthe engineering applica-tion of geotech

12、nics.3.5 geotechnics, nthe application of scientific methodsand engineering principles to the acquisition, interpretation,and use of knowledge of materials of the earths crust to thesolution of engineering problems.3.5.1 DiscussionGeotechnics embraces the fields of soilmechanics, rock mechanics, and

13、 many of the engineeringaspects of geology, geophysics, hydrology, and related sci-ences.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 June 1, 2017. Publishe

14、d June 2017. Originallyapproved in 1986. Last previous edition approved in 2011 as D4595 11. DOI:10.1520/D4595-17.2For 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 th

15、e standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accor

16、dance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13.6 geotextile, nany permeable t

17、extile material used withfoundation, soil, rock, earth, or any other geotechnical engi-neering related material, as an integral part of a man-madeproject, structure, or system.3.7 initial tensile modulus, Ji, (FL1), Nm1, nforgeotextiles, the ratio of the change in tensile force per unitwidth to a ch

18、ange in strain (slope) of the initial portion of aforce-per-unit-width strain curve.3.8 offset tensile modulus, Jo, (FL1), Nm1, nforgeotextiles, the ratio of the change in force per unit width to achange in strain (slope) below the proportional limit point andabove the tangent point on the force-elo

19、ngation curve.3.9 proportional limit, nthe greatest stress which a mate-rial is capable of sustaining without any deviation fromproportionality of stress to strain (Hookes law).3.10 secant tensile modulus, Jsec, (FL1), Nm1, nforgeotextiles, the ratio of change in force per unit width to achange in s

20、train (slope) between two points on a force-per-unit-width strain curve.3.11 tangent point, nfor geotextiles, the first point of theforce-elongation curve at which a major decrease in slopeoccurs.3.11.1 DiscussionThe tangent point is determined bydrawing a tangent line passing through the zero axis

21、and theproportional elastic limit. The point from the zero-force axisthat the force-elongation curve first touches that tangent line isthe tangent point.3.12 tensile modulus, J, (FL1), Nm1, nfor geotextiles,the ratio of the change in tensile force per unit width to acorresponding change in strain (s

22、lope).3.13 tensile strength, nfor geotextiles, the maximum re-sistance to deformation developed for a specific material whensubjected to tension by an external force.3.13.1 DiscussionTensile strength of geotextiles is thecharacteristic of a sample as distinct from a specimen and isexpressed as force

23、 per unit width.3.14 tensile test, nin textiles, a test in which a textilematerial is stretched in one direction to determine the force-elongation characteristics, the breaking force, or the breakingelongation.3.15 wide-width strip tensile test, nfor geotextiles, auniaxial tensile test in which the

24、entire width of a 200-mm(8.0-in.) wide specimen is gripped in the clamps and the gagelength is 100 mm (4.0 in.).3.16 work-to-break, W, (LF), nin tensile testing, the totalenergy required to rupture a specimen.3.16.1 DiscussionFor geotextiles, work-to-break is pro-portional to the area under the forc

25、e-elongation curve from theorigin to the breaking point, and is commonly expressed injoules (inch-pound force).3.17 yield point, nthe first point of the force-elongationcurve above the proportional (linear) section at which anincrease in elongation occurs without a corresponding increasein force.3.1

26、8 For terminology of other terms used in this testmethod, refer to Terminology D123 and Terminology D4439.4. Summary of Test Method4.1 A relatively wide specimen is gripped across its entirewidth in the clamps of a constant rate of extension (CRE) typetensile testing machine operated at a prescribed

27、 rate ofextension, applying a longitudinal force to the specimen untilthe specimen ruptures. Tensile strength, elongation, initial andsecant modulus, and breaking toughness of the test specimencan be calculated from machine scales, dials, recording charts,or an interfaced computer.5. Significance an

28、d Use5.1 The determination of the wide-width strip force-elongation properties of geotextiles provides design parametersfor reinforcement type applications, for example design ofreinforced embankments over soft subgrades, reinforced soilretaining walls, and reinforcement of slopes. When strength isn

29、ot necessarily a design consideration, an alternative testmethod may be used for acceptance testing. Test MethodD4595 for the determination of the wide-width strip tensileproperties of geotextiles may be used for the acceptance testingof commercial shipments of geotextiles, but caution is advisedsin

30、ce information about between-laboratory precision is in-complete (Note 6). Comparative tests as directed in 5.1.1 maybe advisable.5.1.1 In cases of a dispute arising from differences inreported test results when using Test Method D4595 foracceptance testing of commercial shipments, the purchaser and

31、the supplier should conduct comparative tests to determine ifthere is a statistical bias between their laboratories. Competentstatistical assistance is recommended for the investigation ofbias. At a minimum, the two parties should take a group of testspecimens which are as homogeneous as possible an

32、d whichare from a lot of material of the type in question. The testspecimens should then be randomly assigned in equal numbersto each laboratory for testing. The average results from the twolaboratories should be compared using Students t-test forunpaired data and an acceptable probability level cho

33、sen by thetwo parties before the testing began. If a bias is found, either itscause must be found and corrected or the purchaser and thesupplier must agree to interpret future test results in light of theknown bias.5.2 Most geotextiles can be tested by this test method. Somemodification of clamping

34、techniques may be necessary for agiven geotextile depending upon its structure. Special clamp-ing adaptions may be necessary with strong geotextiles orgeotextiles made from glass fibers to prevent them fromslipping in the clamps or being damaged as a result of beinggripped in the clamps. Specimen cl

35、amping may be modified asrequired at the discretion of the individual laboratory, provideda representative tensile strength is obtained. In any event, theprocedure described in Section 10 of this test method forobtaining wide-width strip tensile strength must be maintained.5.3 This test method is ap

36、plicable for testing geotextileseither dry or wet. It is used with a constant rate of extension-type tension apparatus.D4595 1725.4 The use of tensile strength test methods that restrict theclamped width dimension to 50 mm (2 in.) or less, such as theravel, cut strip, and grab test procedures, have

37、been found lesssuitable than this test method for determining design strengthparameters for some geotextiles. This is particularly the casefor nonwoven geotextiles. The wide-width strip technique hasbeen explored by the industry and is recommended in thesecases for geotextile applications.5.4.1 This

38、 test method may not be suited for some wovenfabrics used in geotextile applications that exhibit strengthsapproximately 100 kN/m or 600 lbf/in. due to clamping andequipment limitations. In those cases, 100-mm (4-in.) widthspecimens may be substituted for 200-mm (8-in.) width speci-mens. On those fa

39、brics, the contraction effect cited in 1.4 isminimal and, consequently, the standard comparison can con-tinue to be made.6. Apparatus and Reagents6.1 Tensile Testing MachineA constant rate of extension(CRE) type of testing machine described in Specification D76shall be used. When using the CRE-type

40、tensile tester, therecorder must have adequate pen response to properly recordthe force-elongation curve as specified in Specification D76.6.2 ClampsThe clamps shall be sufficiently wide to gripthe entire width of the sample and with appropriate clampingpower to prevent slipping or crushing (damage)

41、.6.2.1 There are several types of clamp designs available.Three basic clamp design examples are shown in Figs. 1-3.These designs have been used in the laboratory and haveprovided reproducible tensile strengths. These clamps may bemodified to provide greater ease and speed of clamping. In anyevent, c

42、aution must be taken to ensure the type material anddimensions of the clamp are adequate for the users expectedfabric strength. Additional guidance is given in Appendix X5.6.2.2 Size of Jaw FacesEach clamp shall have jaw facesmeasuring wider than the width of the specimen, 200 mm(8 in.), and a minim

43、um of 50-mm (2-in.) length in the directionof the applied force.6.3 External extensometers or other external means ofmeasurement are encouraged for all tests where modulus is tobe measured. In this case, the distance between the moving feetof the extensometer determines the gage length for use inelo

44、ngation calculations and not test speed. Examples of contactand noncontact extensometers are shown in Figs. 5-7. Pleasesee Note 6 and Appendix X5.6.4 Area-Measuring DeviceUse an integrating accessoryto the tensile testing machine or a planimeter.6.5 Distilled Water and Nonionic Wetting Agent, for we

45、tspecimens only.7. Sampling7.1 Lot SampleFor the lot sample, take rolls of geotextilesas directed in an applicable material specification, or as agreedupon between the purchaser and the supplier.NOTE 1The extent of the sampling for wide-width strip tensileproperties is generally defined in an applic

46、able order or contract. Amongthe options available to the purchaser and the supplier is for the purchaserto accept certification by the manufacturer that the material in questionmeets the requirements agreed upon by the two parties, and what the basisfor the certification is, such as, historical dat

47、a generated from materialmanufactured under the same conditions.7.2 Laboratory SampleFor the laboratory sample, take afull-width swatch from each roll in the lot sample. The samplemay be taken from the end portion of a roll, provided there isno evidence it is distorted or different from other portio

48、ns ofthe roll. In cases of dispute, take a sample that will excludefabric from the outer wrap of the roll or the inner wrap aroundthe core.FIG. 1 Wedge ClampsD4595 1737.3 Test SpecimensFor tests in the machine direction andthe cross-machine direction, respectively, take from eachswatch in the labora

49、tory sample the number of specimensdirected in Section 8. Take specimens at random from thelaboratory sample, with those for the measurement of themachine direction tensile properties from different positionsacross the geotextile width, and the specimens for the mea-surement of the cross-machine direction tensile properties fromFIG. 2 Inserts for Wedge ClampsFIG. 3 Roller ClampsFIG. 4 End View of Composite of Clamp, Insert, and Threaded RodD4595 174different positions along the length of the geotextile. Take nospe