1、Designation: D5494 93 (Reapproved 2018)Standard Test Method for theDetermination of Pyramid Puncture Resistance ofUnprotected and Protected Geomembranes1This standard is issued under the fixed designation D5494; the number immediately following the designation indicates the year oforiginal adoption
2、or, in the case of revision, the year of last 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 The test method is to be used as an index test todetermine the pyramid punctu
3、re resistance of geomembranesand, or both, geomembranes protected by nonwoven geotex-tiles and other puncture-protective geosynthetics.1.2 The test method measures the increase of the pyramidpuncture resistance due to the use of protective nonwovengeotextiles with geomembranes.1.3 The values stated
4、in SI units are to be regarded as thestandard value. The values stated in parentheses are providedfor information only.1.4 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-pri
5、ate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelop
6、ment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D76/D76M Specification for Tensile Testing Machines forTextilesD4354 Practice for Sampling of Geosynthetics and Ro
7、lledErosion Control Products (RECPs) for TestingD4439 Terminology for GeosyntheticsD4491/D4491M Test Methods for Water Permeability ofGeotextiles by Permittivity3. Terminology3.1 Definitions:3.1.1 atmosphere for testing geosynthetics, nair main-tained at a relative humidity between 50 to 70 % and at
8、emperature of 21 6 2 C (70 6 4 F).3.1.2 geomembrane, nan essentially impermeable geosyn-thetic composed of one or more synthetic sheets.3.1.2.1 DiscussionIn geotechnical engineering, “essen-tially impermeable” means that no measurable liquid flowsthrough a geosynthetic when tested in accordance with
9、 TestMethods D4491/D4491M.3.1.3 geotextile, na permeable geosynthetic comprisedsolely of textiles.3.1.3.1 DiscussionCurrent manufacturing techniques pro-duce nonwoven fabrics, knitted (non-tubular) fabrics, andwoven fabrics.3.1.4 For other terms, see Terminology D4439.4. Summary of Test Method4.1 A
10、test specimen is clamped without tension betweencircular plates of a ring clamp attachment secured in acompression press or tensile testing machine.Aforce is exertedagainst the center of the unsupported or supported portion ofthe test specimen by a solid steel pyramid attached to a loadindicator unt
11、il rupture of the specimen occurs. The maximumload and elongation recorded is the value of the punctureresistance of the specimen.5. Significance and Use5.1 The pyramid method of puncture resistance is an indextest for the determination of the puncture resistance of unpro-tected geomembranes or geom
12、embranes protected with non-woven geotextiles and other puncture-protective geosynthetics.5.1.1 The purpose of this test method is to establish an indexvalue of puncture resistance by providing standard criteria anda basis for uniform reporting.5.2 This test method may be used for acceptance testing
13、 ofcommercial shipments of geomembranes and geomembranesprotected with nonwoven geotextiles; however, caution isadvised since information about between-laboratory precisionis incomplete.1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility
14、 of D35.10 on Geomembranes.Current edition approved Feb. 1, 2018. Published February 2018. Originallyapproved in 1993. Last previous edition approved in 2011 as D5494 93 (2011).DOI: 10.1520/D5494-93R18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Serv
15、ice at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in a
16、ccordance 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.16. Apparatus6.1 Test SetupA
17、compression press with a reading forceaccuracy of at least 2 N (0.5 lb) is necessary. The press mustmaintain a constant test speed and should be provided with anautomatic chart recorder for the force-versus-deformation be-havior. A clamping device for the test sample, a special piston,and electrical
18、 signal equipment for determining the punctureload are the additional pieces of test equipment needed. Also,a tensile testing machine conforming to the requirements ofSpecification D76/D76M can be utilized in a compressionmode for this test method. The equipment setup shall providea constant rate of
19、 speed, reading accuracy of at least 2 N(0.5 lb). and be provided with an automatic chart recorder forload versus deformation.Additional equipment required by thistest method is described below.6.2 Clamping DeviceThe upper and lower fixing ringclamp, dimensions of which are shown in Fig. 1(a) and (b
20、). Thelower fixing ring shall be provided with a circular recess witha diameter corresponding to the external diameter of thecompression base. This will facilitate mounting of the lowerfixing ring to the compression base as illustrated in Fig. 2.Concentrically arranged grooves shall be located on th
21、e lowerface of the upper ring and upper face of the lower ring tofacilitate nonslip clamping of the test specimen(s).6.3 Compression Base (Fig. 2)CBR-type test presses arenormally equipped with a CBR-cylinder compression basehaving a diameter of 150 mm (6.0 in.) as shown in Fig. 2.Additionally, the
22、compression base must be deep enough toallow the loading piston to plunge at least 100 mm (4.0 in.).The compression base should be manufactured of rust-resistant, high-grade steel.6.4 Underlying Test MediaEither water or an aluminumplate can be used as the underlying medium for this testmethod. The
23、water (which serves as an electrical conductor)simulates a nonrigid underlying medium and the aluminumsimulates a hard, rigid medium. The aluminum plate (Fig. 3)must be placed on the compression base so that the sealingsystem (geomembrane and geotextile) lies flat on it. Thealuminum plate shall be r
24、einforced (possibly with a steel plate)to prevent bending (Fig. 3).6.5 Loading Piston (Fig. 4)The loading piston shall be acylinder with a diameter of 25 6 0.1 mm (1 6 0.004 in.) witha polished and hardened pyramid formed apex as shown in Fig.4. The apex shall be a four-sided pyramid with an apex an
25、gleof 90 rounded off with a radius (R) of 0.5 6 0.01 mm (0.02 60.0004 in.). The edges of the pyramid shall be rounded off witha radius of 0.1 6 0.01 mm (0.004 6 0.0004 in.). The transi-tional edge from the base of the pyramid to the cylinder shallhave a radius (R) of 3.0 6 0.1 mm (0.12 6 0.004 in.).
26、6.6 Electrical Equipment for the Determination of the Punc-ture LoadAn electrical circuit is to be employed between theloading piston and the underlying medium (water or aluminumplate) such that puncture resistance load at failure can bedetermined. The electrical circuit, which is closed at themomen
27、t of puncture, can be connected to a signal lamp and thepuncture resistance load can be recorded at failure.7. Sampling7.1 Lot SampleDivide the product into lots and take thelot sample as directed in Practice D4354.7.2 Laboratory SampleFor the laboratory sample, take aswatch extending the full width
28、 of the geosynthetic, of suffi-cient length from each sample roll so that the requirements of7.3 and Section 9 can be met. Take a sample that will excludematerial from the outer wrap and inner wrap around the core,unless the sample is taken at the production site, in which caseinner and outer wrap m
29、aterial may be used.7.3 Test for Underlying Water MediumThe test specimenshall be cut out with a punch with a diameter greater than80 mm or cut out with a large pair of shears.7.3.1 The sample is fixed between the ring clamps (Figs. 1and 2) so that no slippage occurs.(a) (b)FIG. 1 Upper and Lower Fi
30、xing Ring (Only for Underlying Medium Water)D5494 93 (2018)27.3.2 For Underlying Aluminum Plate MediumTestsample fixing with clamps is not required; deformation of thesample is not induced during testing. With this test condition,any reasonable sample size with a diameter 50 mm (2 in.)can be tested.
31、8. Procedure8.1 Test the conditioned specimens in the standard atmo-sphere for testing as defined in 3.1.8.1.1 Select the load range of the tensile/compression test-ing machine such that the ruptures occur between 10 and 90 %of the full-scale load.8.1.2 Employ an electrical circuit between the loadi
32、ngpiston and the underlying medium (water or aluminum plate).8.2 Method A with Water as the Underlying MediumCenter and secure the specimen between the ring clamps,ensuring that the test specimen extends to or beyond the outerarranged grooves of the ring clamp.8.2.1 Test at a machine speed of 50 6 5
33、 mm min (2 60.2 in. min) until the puncture resistance load is registered bythe electrical equipment as defined in 6.6.8.2.2 If a specimen slips in the clamps, or, if for any reasonattributed to faulty operation the result falls markedly belowthe average for the set of specimens, discard the result
34、and testanother specimen. Continue until the required number ofacceptable breaks has been obtained.8.2.3 Measurement of Elongation at BreakMeasure theelongation at break of the specimen at the same time as thepuncture load is determined (as shown in Fig. 5).8.3 Method B with the Aluminum Plate as th
35、e UnderlyingMediumFixing with clamps is not required; the test speci-mens lie flat on the aluminum plate (see Fig. 3).8.3.1 Test at a machine speed of 1 6 0.1 mm min (0.046 0.004 in. min) until the puncture load is registered by theelectrical equipment as defined in 6.6.9. Test Conditions9.1 When th
36、e underlying medium is water, a constantpuncture resistance load speed of 50 6 5 mm min (2.0 60.2 in. min) shall be maintained.9.2 When the underlying media is an aluminum plate, aconstant puncture resistance load speed of 1.0 6 0.1 mm min(0.04 6 0.004 in. min) shall be maintained.10. Calculation10.
37、1 The average puncture resistance load in N (lb) is to bedetermined by at least ten individual tests, both with theunderlying water medium and the aluminum plate medium.10.2 The elongation at break is to be given in percent andcan only be evaluated when the underlying medium is water.Evaluation of e
38、longation is shown in Fig. 5.where:h = piston movement, in mm, (in.),a = the distance between the inner edge of the fixing ring andthe apex of the pyramid piston before deformation of thetest sample, in mm, (in.),x = the distance between the inner edge of the fixing ring andthe apex of the pyramid p
39、iston at the moment of reachingperforation, in mm, (in.), and = elongation, in %.11. Report11.1 The report shall include the following:11.1.1 Description of test results.11.1.2 Test conditions.11.1.3 The number of tests performed and the averagepuncture resistance load and the elongation, if applica
40、ble.11.1.4 Identification and description of samples.FIG. 2 Method A Test Configuration for Underlying Water MediumFIG.3 MethodBTestConfiguration for Underlying AluminumPlate MediumD5494 93 (2018)312. Precision and Bias12.1 PrecisionThe precision of the procedure in this testmethod is being establis
41、hed.12.2 BiasNo justifiable statement can be made on the biasof the procedure in this test method since the true value cannotbe established by accepted reference methods.12.3 In the event of a dispute arising from differences inreported laboratory acceptance test values resulting from theuse of this
42、 method, purchasers and suppliers should conductcomparative tests to investigate potential statistical bias be-tween the reporting laboratories. Competent statistical assis-tance is recommended during this investigation.At a minimum,the two parties should take a homogenous group of testspecimens fro
43、m the lot of material in question. The testspecimens should then be randomly assigned in equal numbersto each laboratory for retesting. The average results from thetwo laboratories should be compared using Students t-test forunpaired data and an acceptable probability level chosen by thetwo parties
44、before the testing is begun. If a bias is found, eitherits cause must be found and corrected or the purchaser andsupplier must agree to interpret future test results in the light ofthe known bias.13. Keywords13.1 geomembranes; geotextiles; puncture resistanceFIG. 4 Loading PistonFIG. 5 Deformation f
45、or Underlying Water MediaD5494 93 (2018)4ASTM International takes no position respecting the validity of any patent 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 th
46、e riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision 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 o
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49、d 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). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 93 (2018)5
