1、Designation: D5494 93 (Reapproved 2011)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 non-woven 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 non-wovengeotextiles with geomembranes.1.3 The values state
4、d 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 problems, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-p
5、riate 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 TextilesD4354 Practice for Sampling of Geosynthetics for TestingD4439 Terminology for GeosyntheticsD
6、4491 Test Methods for Water Permeability of Geotextilesby Permittivity3. Terminology3.1 Definitions: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 geomembrane, nan essentially impermeable geo-syntheti
7、c 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 TestMethod D4491.3.1.3 geotextile, na permeable geosynthetic comprisedsolely of textiles.3.1.3
8、.1 DiscussionCurrent manufacturing techniques pro-duce non-woven fabrics, knitted (non-tubular) fabrics, andwoven fabrics.3.1.4 For other terms, see Terminology D4439.4. Summary of Test Method4.1 A test specimen is clamped without tension betweencircular plates of a ring clamp attachment secured in
9、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 until rupture of the specimen occurs. The maximumload and elongation recorded is the value of the punctur
10、eresistance 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 geomembranes protected with non-woven geotextiles and other puncture protective geosynthetics.5.1.1 The pu
11、rpose 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 ofcommercial shipments of geomembranes and geomembranesprotected with non-woven geotextiles; however,
12、 caution isadvised since information about between laboratory precisionis incomplete.6. Apparatus6.1 Test Set UpA 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
13、for the force vs. deformation behavior.A clamping device for the test sample, a special piston andelectrical signal equipment for determining the puncture load1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of D35.10 on Geomembranes.
14、Current edition approved June 1, 2011. Published July 2011. Originally approvedin 1993. Last previous edition approved in 2006 as D549493(2006). DOI:10.1520/D5494-93R11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annua
15、l Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.are the additional pieces of test equipment needed. Also, atensile testing ma
16、chine conforming to the requirements ofSpecification D76 can be utilized in a compression mode forthis test method. The equipment set up shall provide a constantrate of speed, reading accuracy of at least 2 N (0.5 lb) and beprovided with an automatic chart recorder for load vs. defor-mation. Additio
17、nal equipment required by this test method isdescribed below.6.2 Clamping DeviceThe upper and lower fixing ringclamp, dimensions of which are shown on Fig. 1a and 1b. Thelower fixing ring shall be provided with a circular recess witha diameter corresponding to the external diameter of thecompression
18、 base. This will facilitate mounting of the lowerfixing ring to the compression base as illustrated on Fig. 2.Concentrically arranged grooves shall be located on the lowerface of the upper ring and upper face of the lower ring tofacilitate non-slip clamping of the test specimen(s).6.3 Compression Ba
19、se (Fig. 2)CBR type test presses arenormally equipped with a CBR-cylinder compression basehaving a diameter of 150 mm (6.0 in.) as shown on Fig. 2.Additionally, the compression base must be deep enough toallow the loading piston to plunge at least 100 mm (4.0 in.).The compression base should be manu
20、factured of rust resistanthigh-grade steel.6.4 Underlying Test MediaEither water or an aluminumplate can be used as the underlying medium for this testmethod. The water (which serves as an electrical conductor)simulates a non-rigid underlying medium and the aluminumsimulates a hard, rigid medium. Th
21、e 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 reinforced (possibly with a steel plate)to prevent bending (Fig. 3).6.5 Loading Piston (Fig. 4)The loading piston shall be acylinder with
22、 a diameter of 25 mm 6 0.1 mm (1 in. 6 0.004in.) with a polished and hardened pyramid formed apex asshown on Fig. 4. The apex shall be a four sided pyramid withan apex angle of 90 rounded off with a radius (R) of 0.5 mm6 0.01 mm (0.02 in. 6 0.0004 in.). The edges of the pyramidshall be rounded off w
23、ith a radius of 0.1 mm 6 0.01 mm (0.004in. 6 0.0004 in.). The transitional edge from the base of thepyramid to the cylinder shall have a radius (R) of 3.0 mm 6 0.1mm (0.12 in.6 0.004 in.).6.6 Electrical Equipment for the Determination of the Punc-ture LoadAn electrical circuit is to be employed betw
24、een 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 themoment of puncture, can be connected to a signal lamp and thepuncture resistance load can be recorded at failure.7. S
25、ampling7.1 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 of the geosynthetic, of suffi-cient length from each sample roll so that the requirements ofSections 7.3 and 9 c
26、an be met. Take a sample that will excludematerial from the outer wrap and inner wrap around the coreunless the sample is taken at the production site, in which caseinner and outer wrap material may be used.7.3 Test for underlying water medium: The test specimenshall be cut out with a punch with a d
27、iameter greater than 80mm or cut out with a large pair of shears.7.3.1 The sample is fixed between the ring clamps (Fig. 1and Fig. 2) so that no slippage occurs.7.3.2 For underlying aluminum plate medium: Test samplefixing with clamps is not required; deformation of the sampleis not induced during t
28、esting. With this test condition anyreasonable sample size with a diameter 50 mm (2 in.) can betested.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 rupture
29、s occur between 10 and 90 %of the full-scale load.(a) (b)FIG. 1 Upper and Lower Fixing Ring (Only for Underlying Medium Water)D5494 93 (2011)28.1.2 Employ an electrical circuit between the loadingpiston and the underlying medium (water or aluminum plate).8.2 Method A with water as the underlying med
30、ium: centerand secure the specimen between the ring clamps ensuring thatthe test specimen extends to or beyond the outer arrangedgrooves of the ring clamp.8.2.1 Test at a machine speed of 50 + 5 mm/min (2 in./min6 0.2 in./min) until the puncture resistance load is registeredby the electrical equipme
31、nt 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 and testanother specimen. Continue until the required number ofacceptable breaks has been obtained.8
32、.2.3 Measurement of Elongation at Break Measure 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 the underlyingmedium: fixing with clamps is not required, the test specimenslie flat on the aluminum
33、plate (see Fig. 3).8.3.1 Test at a machine speed of 1 + 0.1 mm/min (0.04in./min + 0.004 in./min) until the puncture load is registered bythe electrical equipment as defined in 6.6.9. Test Conditions9.1 When the underlying medium is water, a constantpuncture resistance load speed of 50 mm/min 6 5 mm/
34、min (2.0in./min6 0.2 in./min) shall be maintained.9.2 When the underlying media is an aluminum plate aconstant puncture resistance load speed of 1.0 mm/min 6 0.1mm/min (0.04 in./min 6 0.004 in./min) shall be maintained.10. Calculation10.1 The average puncture resistance load in N (lb) is to bedeterm
35、ined by at least 10 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 with the underlying medium is water.Evaluation of elongation is shown on Fig. 5.where:h = piston movement in mm, (i
36、n.),a = the distance between the inner edge of the fixing ringand the apex of the pyramid piston before deformationof the test sample in mm, (in.),x = the distance between the inner edge of the fixing ringand the apex of the pyramid piston at the moment ofreaching perforation in mm, (in.), and = elo
37、ngation, 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 applicable.11.1.4 Identification and description of samples.12. Precision an
38、d Bias12.1 PrecisionThe precision of the procedure in this testmethod is being established.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
39、 differences inreported laboratory acceptance test values resulting from theuse of this method; purchasers and suppliers should conductFIG. 2 Method A: Test Configuration for Underlying Water MediumFIG. 3 Method B: Test Configuration for Underlying AluminumPlate MediumD5494 93 (2011)3comparative tes
40、ts 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 from the lot of material in question. The testspecimens should the
41、n 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 before the testing is begun. If a bias is found, eitherits caus
42、e 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 for Underlying Water MediaD5494 93 (2011)4ASTM International tak
43、es 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 the riskof infringement of such rights, are entirely their own re
44、sponsibility.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 of this standard or for additional standardsand should be addres
45、sed to ASTM International Headquarters. Your comments 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 th
46、e address shown below.This standard is copyrighted 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-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D5494 93 (2011)5
