1、Designation: D 6241 04Standard Test Method for theStatic Puncture Strength of Geotextiles and Geotextile-Related Products Using a 50-mm Probe1This standard is issued under the fixed designation D 6241; the number immediately following the designation indicates the year oforiginal adoption or, in the
2、 case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method is an index test used to measure theforce required to puncture a geo
3、textile and geotextile-relatedproducts. The relatively large size of the plunger provides amultidirectional force on the geotextile.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to addre
4、ss 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 determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D76 Specificati
5、on for Tensile Testing Machines for TextilesD 123 Terminology Relating to TextilesD 1776 Practice for Conditioning Textiles for TestingD 1883 Test Method for CBR (California Bearing Ratio) ofLaboratory-Compacted SoilsD 4354 Practice for Sampling of Geotextiles for TestingD 4439 Terminology for Geosy
6、ntheticsE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodNOTE 1Test Method D 1883 describes a mold (CBR mold) that canbe used for this test method.3. Terminology3.1 DefinitionsFor definitions of other textile terms usedin this test method, refer to Ter
7、minology D 123. For definitionsof other terms relating to geosynthetics used in this testmethod, refer to Terminology D 4439.3.2 Definitions of Terms Specific to This Standard:3.2.1 atmoshere for testing geotextiles, nair maintained ata relative humidity of 50 to 70 % and a temperature of 21 62C (70
8、 6 4F).3.2.2 geotextile, na permeable geosynthetic composedsolely of textiles.3.2.3 puncture resistance, nthe inherent resisting mecha-nism of the test specimen to the failure by a penetrating orpuncturing object.4. Summary of Test Method4.1 A test specimen is clamped without tension betweencircular
9、 plates and secured in a tensile or compression testingmachine, or both. A force is exerted against the center of theunsupported portion of the test specimen by a steel plungerattached to the load indicator until rupture occurs. The maxi-mum force is the value of puncture strength.5. Significance an
10、d Use5.1 This test method for determining the puncture strengthof geotextiles is to be used by the industry as an index ofpuncture strength. The use of this test method is to establish anindex value by providing standard criteria and a basis foruniform reporting.5.2 This test method is considered sa
11、tisfactory for accep-tance testing of commercial shipments of geotextiles.5.3 In case of a dispute arising from differences in reportedtest results when using this test method for acceptance testingof commercial shipments, the purchaser and the suppliershould conduct comparative tests to determine i
12、f there is astatistical bias between their laboratories. Competent statisticalassistance is recommended for the investigation of bias. As aminimum, the two parties should take a group of test speci-mens that are as homogeneous as possible and that are from alot of the type in question. The test spec
13、imens then should berandomly assigned in equal numbers to each laboratory fortesting. The average results from the two laboratories should becompared using Students t-test for unpaired data and anacceptable probability level chosen by the two parties beforethe testing is begun. If a bias is found, e
14、ither its cause must be1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics is the direct responsibility of Subcommittee D35.01 on MechanicalPropertiesCurrent edition approved Nov. 1, 2004. Published December 2004. Originallyapproved in 1998. Last previous edition approv
15、ed in 1999 as D 6241 99.2For 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 page onthe ASTM website.1*A Summary of Changes section appear
16、s at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.found and corrected, or the purchaser and the supplier mustagree to interpret future test results in the light of the knownbias.5.4 This test method is not
17、applicable to materials that aremanufactured in sizes that are too small to be placed into thetest apparatus in accordance with the procedures in this testmethod. Furthermore, it is not appropriate to separate plies ofa geosynthetic or geocomposite for use in this test method.6. Apparatus6.1 Testing
18、 Machine, must be constant-rate-of extension(CRE) type, with autographic recorder conforming to therequirement of Specification D 76.6.2 Plunger, with a flat diameter of 50 mm 6 1 mm with aradial edge of 2.5 mm 6 0.5 mm. See Fig. 1.6.3 Clamping Apparatus, consisting of concentric plateswith an inter
19、nal diameter of 150 mm (5.9 in.), capable ofclamping the test specimen without slippage (limit slippage oftest specimen to 5 mm). The external diameter is suggested tobe 250 mm (9.8 in.). The diameter of the holes used forsecuring the ring clamp assemblage is suggested to be 11 mm(7/16 in.) and equa
20、lly spaced at a diameter of 220 mm (8.7 in.).The surfaces of these plates can consist of grooves with rubberO-rings or coarse sandpaper bonded onto opposing surfaces. Itis suggested that 9.5-mm (3/8-in.) bolts be welded to thebottom plate so that the top plate can be placed over the boltsand nuts ea
21、sily tightened. A guide block may be used to helpseat the material being clamped. Other clamps that eliminateslippage are acceptable. See Fig. 2 and Fig. 3.NOTE 2Plans for a hydraulic clamping apparatus are on file atASTM.7. Sampling7.1 Lot SampleIn the absence of other guidelines, dividethe product
22、 into lots and take lot samples as specified inPractice D 4354.7.2 Laboratory SampleConsider the units in the lotsample as the units in the laboratory sample. For the laboratorysample, take a full width sample of sufficient length along theselvage or edge of the roll so that the requirements of 7.3t
23、hrough 7.5.2 can be met. Exclude the inner and outer wraps ofthe roll or any material containing folds, crushed areas, or otherdistortions not representative of the sample lot.7.3 Remove test specimens from the laboratory sample in arandomly distributed pattern across the width with no specimenNOTE
24、1All dimensions are in millimetres.NOTE 2This diagram is not to scale.FIG. 1 PlungerD6241042taken nearer the selvage of fabric edge than 1/20 of the fabricwidth or 150 mm (6 in.), whichever is the smaller, unlessotherwise specified.7.4 Test SpecimensFrom each unit in the laboratorysample, cut the sp
25、ecimens so that the edge of specimen willextend beyond the edge of the clamp by 10 mm (0.39 in.) in alldirections.7.5 Number of SpecimensUnless otherwise agreed upon,as when provided in an applicable material specification, takea number of test specimens per laboratory sample such that theuser may e
26、xpect at the 95 % probability level that the test resultis not more than 5.0 % of the average above or below the trueaverage of sample. Determine the number of specimens persample as follows:NOTE 1All dimensions are in millimetres.NOTE 2This diagram is not to scale.FIG. 2 Typical Arrangement for Tes
27、t on Tensile Testing Machine (Method A)D62410437.5.1 Reliable Estimate of vWhen there is a reliableestimate of v based upon extensive past records for similarmaterials tested in the users laboratory as directed in this testmethod, calculate the required number of specimens as fol-lows:n 5 tv/A!2(1)w
28、here:n = number of test specimens (rounded upward to a wholenumber),v = reliable estimate of the coefficient of variation forindividual observations on similar materials in theusers laboratory under conditions of single-operationprecision, %,NOTE 1All dimensions are in millimetres.NOTE 2The diagram
29、is not to scale.FIG. 3 Typical arrangement for test on compression testing machine (method B)D6241044t = the value of Students t one-sided limits, a 95 %probability level, and the degrees of freedom, associ-ated with the estimate of v, andA = 5.0 % of the average, the value of the allowablevariation
30、.7.5.2 No Reliable Estimate of vWhen there is no reliableestimate of v for the users laboratory, the equation given in7.5.1 should not be used directly. Instead, specify the fixednumber (10) of specimens. The number of specimens iscalculated using v = 9.5 % of the average. These values for vare some
31、what larger than usually found in practice. When areliable estimate of v for the users laboratory becomesavailable, the equation given in 7.5.1 usually will require fewerthan the fixed number of specimens.NOTE 3If the material to be tested is known to have differentcharacteristics on the two sides,
32、for example, physical characteristics of asa consequence of the manufacturing process, then the complete test shallbe carried out separately on each face.8. Conditioning8.1 Bring the specimens to moisture equilibrium in theatmosphere for testing geotextiles. Equilibrium is considered tohave been rea
33、ched when the increase in mass of the specimenin successive weightings made at intervals of not less than 2 hdoes not exceed 0.1 % of the mass of the specimen. In generalpractice, the industry approaches equilibrium from the “asreceived” side.NOTE 4It is recognized that in practice geotextiles mater
34、ials fre-quently are not weighted to determine when moisture equilibrium hasbeen reached. While such a procedure cannot be accepted in cases ofdispute, it may be sufficient in routine testing to expose the material to thestandard atmosphere for testing for a reasonable period of time before thespeci
35、mens are tested. At lease 24 h has been found acceptable in mostcases. However, certain fibers may exhibit slow moisture equalizationrates from the “as received” wet side. When this is known, a precondi-tioning cycle, as described in Practice D 1776, may be agreed uponbetween contractual parties.9.
36、Procedure9.1 Select the load range of the tensile testing machine suchthat the rupture occurs between 10 and 90 % of the full-scaleload.9.2 Center and secure the test specimen between the holdingplates ensuring that the test specimen extends to or beyond theouter edges of the clamping plates.9.3 Mar
37、k the test specimen along the inside circumferenceof the holding container. This allows for a measurement ofpotential slippage of the specimen.9.4 If slippage greater than 5 mm is observed, the test onthat specimen should be discarded and a new specimen shouldbe obtained.9.5 Test at a machine speed
38、of 50 mm/min (approximately 2in./min) until the puncture rod completely ruptures the testspecimen. Read the puncture strength and displacement fromthe greatest force registered on the recording instrument duringthe test. For the testing of composite geotextiles, there may bea double peak. If so, the
39、 initial value should be reported evenif the second peak is higher than the first one.10. Calculation10.1 Calculate the average of the puncture strength for alltest results as read directly from the recording instrument.11. Report11.1 State that the material was tested in accordance withTest Method
40、D 6241 . State the manner in which the specimenswere conditioned. Describe the material or product sample andthe method of sampling used.11.2 Report the following information:11.2.1 The method of holding the test specimen in theclamping device.11.2.2 The average puncture strength of the specimenstes
41、ted.11.2.3 The variation of data within each group of speci-mens.11.2.4 The variation, if any, from the described test method.11.3 Upon request, the graph of plunger force versus dis-placement. A typical graph is given in Fig. 4.12. Precision and Bias12.1 Precision.12.1.1 Interlaboratory Testing Pro
42、gramsAn inter-laboratory testing program (ILS) was performed in 2003. Thedesign of the experiment, similar to that of Practice E 691.A270g/m2 (8-oz/sy) needle-punched nonwoven geotextile and a540g/m2 (16-oz/sy) needle-punched nonwoven geotextile werecirculated to eight laboratories.12.1.2 . Test Res
43、ults The precision information is pre-sented in Table 1 for the four materials. The average valueslisted for the strength test results are in units of N (lbs).12.2 BiasThe procedure in this test method for measuringthe static puncture strength of geotextiles using a 50-mm probehas no bias because th
44、e values of puncture strength can only bedefined in terms of a test method.D6241045SUMMARY OF CHANGESThis section identifies the location of changes to this test method since the last edition.(1) Precision and Bias text was added.ASTM International takes no position respecting the validity of any pa
45、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
46、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
47、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
48、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-
49、mail); or through the ASTM website(www.astm.org).FIG. 4 Example of typical curve, plunger force versus plunger displacementMaterial Average Puncture Strength95% Confidence Repeatability Limit95% Confidence Reproducibility Limit(8-oz/sy) Nonwoven Geotextile 3045 (684) 11.3 15.3(16-oz/sy) Nonwoven Geotextile7133 (1603) 10.3 15.4D6241046
