1、Designation: D 4595 09Standard Test Method forTensile Properties of Geotextiles by the Wide-Width StripMethod1This standard is issued under the fixed designation D 4595; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of l
2、ast 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 me
3、thod. 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 directions
4、for 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
5、measuring strip tensile properties is the width ofthe specimen. This width, by contrast, is greater than the lengthof the 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
6、this test method minimizes the contraction effect of thosefabrics and 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
7、 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:2D76 Specification for Tensile Testing Machines for TextilesD 123 Terminology Relating to TextilesD 57
8、9 Specification for Greige Woven Glass FabricsD 1776 Practice for Conditioning and Testing TextilesD 2905 Practice for Statements on Number of Specimensfor Textiles3D 4439 Terminology for Geosynthetics3. Terminology3.1 atmosphere for testing geotextiles, n.air maintained ata relative humidity of 65
9、6 5 % and a temperature of 21 6 2C(70 6 4F).3.2 breaking toughness, T, (FL1), Jm2, n.for geotextiles,the actual work-to-break per unit surface area of material.3.2.1 DiscussionBreaking toughness is proportional tothe area under the force elongation curve from the origin tothe breaking point (see als
10、o work-to-break). Breaking tough-ness is calculated from work-to-break, gage length, and widthof a specimen.3.3 corresponding force, Fc,n.the force associated with aspecific elongation on the force-per-unit-width strain curve.(Syn. load at specified elongation, LASE.)3.4 geotechnical engineering, n.
11、the engineering applica-tion of geotechnics.3.5 geotechnics, n.the 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 fiel
12、ds of soilmechanics, rock mechanics, and many of the engineeringaspects of geology, geophysics, hydrology, and related sci-ences.3.6 geotextile, n.any permeable textile material used withfoundation, soil, rock, earth, or any other geotechnical engi-neering related material, as an integral part of a
13、man-madeproject, structure, or system.3.7 initial tensile modulus, Ji, (FL1), Nm1, n.for geo-textiles, the ratio of the change in tensile force per unit width1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.01 on M
14、echani-cal Properties.Current edition approved Jan. 15, 2009. Published March 2009. Originallyapproved in 1986. Last previous edition approved in 2005 as D 4595 05.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Boo
15、k of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, U
16、nited States.to a change in strain (slope) of the initial portion of a force perunit width strain curve.3.8 offset tensile modulus, Jo, (FL1), Nm1, n.for geo-textiles, the ratio of the change in force per unit width to achange in strain (slope) below the proportional limit point andabove the tangent
17、 point on the force elongation curve.3.9 proportional limit, n.the greatest stress which a ma-terial is capable of sustaining without any deviation fromproportionality of stress to strain (Hookes law).3.10 secant tensile modulus, Jsec(FL1), Nm1, n.forgeotextiles, the ratio of change in force per uni
18、t width to achange in strain (slope) between two points on a force per unitwidth strain curve.3.11 tangent point, n.for 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
19、 through the zero axis and theproportional elastic limit. The point from the zero force axisthat the force elongation curve first touches that tangent lineis the tangent point.3.12 tensile modulus, J, (FL1), Nm1, n.for geotextiles,the ratio of the change in tensile force per unit width to acorrespon
20、ding change in strain (slope).3.13 tensile strength, n.for geotextiles, the maximumresistance to deformation developed for a specific materialwhen subjected to tension by an external force.3.13.1 DiscussionTensile strength of geotextiles is thecharacteristic of a sample as distinct from a specimen a
21、nd isexpressed in force per unit width.3.14 tensile test, n.in textiles, a test in which a textilematerial is stretched in one direction to determine theforce elongation characteristics, the breaking force, or thebreaking elongation.3.15 wide-width strip tensile test, n.for geotextiles,auniaxial ten
22、sile test in which the 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), n.in tensile testing, the totalenergy required to rupture a specimen.3.16.1 DiscussionFor geotextiles, work-to-break is pro-portional to
23、 the area under the force elongation curve fromthe origin to the breaking point, and is commonly expressed injoules (inch-pound-force).3.17 yield point, n.the first point of the force elongationcurve above the proportional (linear) section at which anincrease in elongation occurs without a correspon
24、ding increasein force.3.18 For terminology of other terms used in this testmethod, refer to Terminology D 123 and Terminology D 4439.4. 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 machi
25、ne operated at a prescribed rate of exten-sion, applying a longitudinal force to the specimen until thespecimen ruptures. Tensile strength, elongation, initial andsecant modulus, and breaking toughness of the test specimencan be calculated from machine scales, dials, recording charts,or an interface
26、d computer.5. Significance and Use5.1 The determination of the wide-width stripforce elongation properties of geotextiles provides designparameters for reinforcement type applications, for exampledesign of reinforced embankments over soft subgrades, rein-forced soil retaining walls, and reinforcemen
27、t of slopes. Whenstrength is not necessarily a design consideration, an alterna-tive test method may be used for acceptance testing. TestMethod D 4595 for the determination of the wide-width striptensile properties of geotextiles may be used for the acceptancetesting of commercial shipments of geote
28、xtiles but caution isadvised since information about between-laboratory precisionis incomplete (Note 7). Comparative tests as directed in 5.1.1may be advisable.5.1.1 In cases of a dispute arising from differences inreported test results when using Test Method D 4595 foracceptance testing of commerci
29、al shipments, the purchaser andthe supplier should conduct comparative tests to determine ifthere is a statistical bias between their laboratories. Competentstatistical assistance is recommended for the investigation ofbias.As a minimum, the two parties should take a group of testspecimens which are
30、 as homogeneous as possible and 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 ac
31、ceptable probability level chosen 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 the light ofthe known bias.5.2 Most geotextiles can be tested by this test met
32、hod. Somemodification of clamping 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 being
33、gripped in the clamps. Specimen clamping may be modified asrequired at the discretion of the individual laboratory providinga 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 mai
34、ntained.5.3 This test method is applicable for testing geotextileseither dry or wet. It is used with a constant rate of extensiontype tension apparatus.5.4 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 gra
35、b test procedures, have 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
36、 applications.5.4.1 This 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 andD4595092equipment limitations. In those cases, 100-mm (4-in.) widthspecimens may be substituted for 200-mm (8-in
37、.) width speci-mens. On those fabrics, 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 b
38、e used. When using the CRE type tensile tester, therecorder must have adequate pen response to properly recordthe forceelongation 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 preven
39、t slipping or crushing (damage).6.2.1 Three basic clamp designs are shown in Fig. 1, Fig. 2,Fig. 3, Fig. 4, and Fig. 5. These designs have been used in thelaboratory and have provided reproducible tensile strengths.These clamps may be modified to provide greater ease andspeed of clamping. In any eve
40、nt, caution must be taken toensure the type material and dimensions of the clamp areadequate for the users expected fabric strength.NOTE 1When roller clamps are used an external extensometer, perFig. 3, is often used to determine displacement. External extensometers orother external means of measure
41、ment are encouraged for all tests wheremodulus is to be measured. In this case, the distance between the movingfeet of the extensometer determines the gage length for use in elongationcalculations and not test speed. Please see Note 7.6.2.2 Size of Jaw FacesEach clamp shall have jaw facesmeasuring w
42、ider than the width of the specimen, 200 mm (8in.), and a minimum of 50-mm (2-in.) length in the direction ofthe applied force.6.3 Area-Measuring DeviceUse an integrating accessoryto the tensile testing machine or a planimeter.6.4 Distilled Water and Nonionic Wetting Agent, for wetspecimens only.7.
43、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 2The extent of the sampling for wide-width strip tensileproperties is generally defined in an applicable order or contr
44、act. Amongthe options available to the purchaser and the supplier is for the purchaserFIG. 1 Wedge ClampsD4595093to 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, histor
45、ical data generated from materialmanufactured under the same conditions.FIG. 2 Inserts for Wedge ClampsFIG. 3 Roller ClampsD45950947.2 Laboratory SampleFor the laboratory sample, take afull-width swatch approximately 1 m (40 in.) long in themachine direction from each roll in the lot sample. The sam
46、plemay be taken from the end portion of a roll provided there isno evidence it is distorted or different from other portions 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.7.3 Test SpecimensFor tests in the mach
47、ine direction andthe cross-machine direction, respectively, take from eachswatch in the laboratory 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 positio
48、nsacross the geotextile width, and the specimens for the mea-surement of the cross-machine direction tensile properties fromdifferent positions along the length of the geotextile. Take nospecimens nearer the selvage or edge of the geotextile than1/10 the width of the geotextile (see 8.2).8. Test Spe
49、cimen Preparation8.1 Number of Specimens:8.1.1 Unless otherwise agreed upon, as when specified in anapplicable material specification, take a number of specimensFIG. 4 End View of Composite of Clamp, Insert, and Threaded RodFIG. 5 Sanders ClampD4595095per fabric swatch such that the user may expect at the 95 %probability level that the test result is not more than 5.0 % ofthe average above or below the true average of the swatch foreach, the machine and cross-machine direction, respectively.Determine the number of spe
