ASTM D5397-2019 Standard Test Method for Evaluation of Stress Crack Resistance of Polyolefin Geomembranes Using Notched Constant Tensile Load Test.pdf

1、Designation: D5397 07 (Reapproved 2012)D5397 19Standard Test Method forEvaluation of Stress Crack Resistance of PolyolefinGeomembranes Using Notched Constant Tensile Load Test1This standard is issued under the fixed designation D5397; the number immediately following the designation indicates the ye

2、ar oforiginal adoption 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 This test method is used to develop test data from whi

3、ch the susceptibility of polyolefin geomembrane sheet material tostress cracking under a constant tensile load condition and an accelerated environmental condition can be evaluated.1.2 This test method measures the failure time associated with a given test specimen at a specified tensile load level.

4、 Resultsfrom a series of such tests utilizing a range of load levels can be used to construct a stress-time plot on a log-log axis.1.3 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are provided forinformation only.1.4 This standard does n

5、ot purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1.5 This int

6、ernational standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Co

7、mmittee.2. Referenced Documents2.1 ASTM Standards:2D638 Test Method for Tensile Properties of PlasticsD883 Terminology Relating to PlasticsD4354 Practice for Sampling of Geosynthetics and Rolled Erosion Control Products (RECPs) for TestingD4439 Terminology for GeosyntheticsD4703 Practice for Compres

8、sion Molding Thermoplastic Materials into Test Specimens, Plaques, or SheetsD4833D5199 Test Method for Index Puncture Resistance of Geomembranes and Related ProductsMeasuring the NominalThickness of GeosyntheticsD6693/D6693M Test Method for Determining Tensile Properties of Nonreinforced Polyethylen

9、e and Nonreinforced FlexiblePolypropylene Geomembranes3. Terminology3.1 Definitions:3.1.1 actual thickness, nindividual measurement per Test Method D5199, on a specimen tab.3.1.2 average thickness, nresult of Test Method D5199 testing, that is, average of ten specimens.3.1.3 geomembrane, nvery low p

10、ermeability synthetic membrane liners or barriers used with any geotechnical engineeringrelated engineering-related material so as to control fluid migration in a man-made project, structure, or system (see Test Methodsystem.D4833).3.1.4 ligament, nthe portion of geomembrane that remains uncut under

11、 the notch.3.1.5 ligament thickness, nlength of the ligament measured from the bottom of the notch to the edge of the specimen in adirection perpendicular to the plane of the test specimen.1 This test method is under the jurisdiction of ASTM Committee D35 on Geosynthetics and is the direct responsib

12、ility of Subcommittee D35.02 on Endurance Properties.Current edition approved July 1, 2012Jan. 1, 2019. Published July 2012January 2019. Originally approved in 1993. Last previous edition approved in 20072012 asD5397 07.D5397 07 (2012). DOI: 10.1520/D5397-07R12.10.1520/D5397-19.2 For referencedASTM

13、standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of

14、an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as publ

15、ished by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.6 multi-component geomembrane, na geomembrane that includes multiple layers of different nature.3.1.7 nominal thickness, nthe

16、thickness specified without regard of tolerance.3.1.8 notch, ncut made using a specified tool in prescribed conditions.3.1.9 slow crack growth, ntype of fracture mechanism characterized by the stable growth of a crack with little deformationin the material.3.1.10 smooth geomembrane, na geomembrane t

17、hat does not present any surface texture.3.1.10.1 DiscussionA geomembrane can be smooth on one side but textured on the other side.3.1.11 stress crack, nan external or internal crack in a plastic caused by tensile stresses less than its short-time mechanicalstrength (see DefinitionsTerminology D883)

18、.3.1.11.1 DiscussionThe development of such cracks is frequently accelerated by the environment to which the plastic is exposed. The stresses thatcause cracking may be present internally or externally or may be combinations of these stresses.3.2 For definitions of other terms relating to geotextiles

19、 and geomembranes used in this standard, refer to Terminology D4439.4. Summary of Test Method4.1 This test method consists of subjecting a dumbbell shaped dumbbell-shaped notched test specimen from a polyolefin sheetto a constant tensile load in the presence of a surface-active agent and at an eleva

20、ted temperature. The time to failure of the testspecimen is recorded. The results of a series of such tests conducted at different stress levels are presented by plotting stress levelagainst failure time for each stress level on a log-log axis.5. Significance and Use5.1 This test method does not pur

21、port to interpret the resulting response curve. Such interpretation is left to the parties involvedin the commissioning and reporting of the test results.5.2 This test method is intended as an index test and may be used for grading polyolefin geomembrane sheets in regard to theirstress cracking stre

22、ss-cracking sensitivity.5.2.1 Conditions that can affect stress cracking include: level of loading, test temperature and environment, microstructure,polymer additive package, processing history, and thermal history.5.3 The test method is applicable to smooth, homogeneous polyolefin geomembranes wher

23、e the two sides are parallel to permitapplication of the stress on a well-defined surface delimited by the surface of the geomembrane on one side, and the bottom ofthe notch on the other side.5.4 The test is applicable to textured geomembranes when prepared as described in 8.3.2.5.5 The test may be

24、applicable to multi-component geomembranes (such as white, conductive, or other non-homogeneoussheets) or limited to the evaluation of the base polymer when prepared as described in 8.3.3.5.6 The test is not applicable to bituminous, EPDM, plasticized PVC, and other non-polyolefin geomembranes, as t

25、hesematerials are not susceptible to slow crack growth.5.7 This test method may not be applied to polyolefin geomembranes that do not exhibit a well-defined yield point, such as someVLDPE and LLDPE.6. Apparatus6.1 Blanking DieA die suitable for cutting test specimens to the dimensions and tolerances

26、 shown in Fig. 1.NOTE 1The length of the specimen can be changed to suit the design of the test apparatus. However, there should be a constant neck section withlength at least 1312.7 mm (0.5 in.) long. The width should be 3.20 mm (0.125 in.).in.) 6 0.025 mm.6.2 Notching DeviceA device or machine tha

27、t can produce a consistent notch depth.NOTE 2An evaluation of the notching technique can be performed by quenching a notched specimen in liquid nitrogen and then fracturing it. Thenotch depth can readily be measured by examining the fracture surface under a reflected light microscope. Other methods

28、of verifying notch depth includeviewing the cut specimen on its side in a microscope with the aid of a eyepiece micrometer or a calibrated reticle.6.3 BladeA single-edged razor made of carbon steel. The tip profile is that of an arrow rather than that of a chisel point. Thesharpness of the point is

29、critical to the cleanliness of the cut, which effectsaffects the results of the test significantly.D5397 1926.4 Stress Cracking Stress-Cracking ApparatusEquipment suitable for subjecting test specimens to a tensile stress of up to13.8 MPa (2000 lb/in.2). The specimens shall be maintained at a consta

30、nt temperature of 50 6 1C1 C (122 6 2F)2 F) whilebeing totally immersed in a surface-active agent. The solution should be constantly agitated to provide a uniform concentrationthroughout the bath.NOTE 3The apparatus shown in Fig. 2 is one type that has been used and is capable of testing up to 20 sp

31、ecimens at a time. This equipment usesa lever system with a mechanical advantage (MA) of three to impose the desired loading on each specimen. The surface-active agent in which thespecimens are immersed is contained in an open stainless steel tank.Asubmersion heater and controller are used to mainta

32、in the test temperature.Apumpkeeps the liquid in a constant state of agitation. A timing clock for each test specimen is also provided to record automatically the failure time of the testspecimens to the nearest 0.1 h.NOTE 4If “on/off” switches are used to control the timing clock, the switch must b

33、e sensitive enough to be turned off under 200 g of the force.7. Reagent7.1 The reagent should consist of 10 % surface-active agent with 90 % deionized water. The surface-active agent is IgepalCO-6303 that is nonylphenoxy poly(ethyleneoxy)ethanol. The reagent should be stored in a closed container. T

34、he reagent in thebath should be replaced every two weeks to maintain a constant concentration.NOTE 5In caseThe pH of dispute, the water should be distilled or deionized at the discretion of the parties involved.the reagent may also be monitoredthroughout the duration of the test, and the solution re

35、placed when a change in pH is detected. Without evidence of the chemical stability of the solution,the solution must be replaced every two weeks.NOTE 6Other incubation solutions may also be used in the test, provided that the parties involved mutually agree to the changes and state the specificdetai

36、ls in the final report.8. Sampling8.1 Lot SampleDivide the product into lots and take the lot sample as directed in Practice D4354.8.2 Laboratory SampleAs a laboratory sample for acceptance testing, take a full-width swatch approximately 1 m (40 in.)(40 in.) long in the machine direction from each r

37、oll in the lot sample. The sample may be taken from the end portion of a roll,provided there is no evidence it is distorted or different from other portions of the roll.8.3 Selection of the Location Where to Cut the Specimens:3 Igepal CO-630 may be obtained from Rhone-Poulenc, CN 7500, Prospect Plai

38、ns Road, Cranbury, NJ 08512-7500.NOTE 1DimensionedDimensions in millimetres to an accuracy of 0.02 mm.0.025 mm unless otherwise indicated.FIG. 1 Dimensions of Test Method D1822 Type “L” Test SpecimensNOTE 1The number of positions in the test frame is optional.FIG. 2 Constant Stress Loading Apparatus

39、 Consisting of Twenty20 Specimen Test PositionsD5397 1938.3.1 For smooth geomembranes manufactured with a single polymer formulation, proceed to 8.4.8.3.2 For textured geomembranes manufactured with a single polymer formulation in all layers, test the smooth edges ifavailable. If the membrane does n

40、ot have smooth edges, prepare a plaque according to Practice D4703, Procedure C. Proceed to8.4, considering this plaque as the laboratory sample. Report that the sample was tested as a plaque in addition to the otherreporting requirements.NOTE 7Results obtained on a sample prepared from the actual g

41、eomembrane sheet (that is, as per 8.3.1) may differ from those obtained on the samesample, but using specimens cut out from a plaque prepared using Practice D4703, Procedure C (that is, as per 8.3.2). Caution is required when analyzingthe results and comparing products.8.3.3 For other types of geome

42、mbrane, refer to Appendix X2 for specific guidance.8.4 Test SpecimensAt least thirty30 test specimens are cut from each swatch in the laboratory sample. For each set of tests,all specimens must be taken from one direction.NOTE 8Quite often the test is required to challenge the weakest direction of t

43、he sheet material. If this is the cross machine direction, the test specimensshould be cut in thisIf not specified, the cross-machine direction shall be tested. When testing the cross direction, specimens are oriented in that direction.Hence the notch is placed in the machine direction so that the s

44、pecimens are stressed in the desired cross machine cross-machine direction.NOTE 9It has been found that inserting a grommet or eyelet in the two holes at the end tabs of the test specimen helps to reduce the number of “gripfailures” or failures occurring outside of the neck section of the specimen.9

45、. Procedure9.1 Measure the thickness per Test Method D5199 of each individual test specimen at its minimum cross section to the nearest0.0130.025 mm (0.001 in.). (0.001 in.). The variation in thickness should not be greater than 6 0.026 mm (6 0.002 in.) 65 % ofthe nominalaverage thickness of the lab

46、oratory sample of geomembrane.9.2 Cut into each specimen a control imperfection (notch) on one surface as shown in Fig. 3. The depth of the notch shouldproduce a ligament thickness of 80 % 6 1 % of the nominal thickness of the specimen.laboratory sample.NOTE 10Using this procedure, the actual notch

47、depth will vary in accordance with the actual thickness of the test specimen. For example, a sheetof nominal thickness of 2 mm (80 mil) might have thicknesses ranging from 1.98 to 2.08 mm (78 to 82 mil). To obtain a constant hingeligament thicknessof 1.61.62 mm (64 mil), the notch depth would vary f

48、rom 0.36 to 0.46 mm (14 to 18 mil), depending upon the actual thickness of the individual testspecimens.FIG. 3 Front and Side Views of the Notched Test Specimen of NCTL TestD5397 1949.3 Inspect the edge of the blade for scratches and burrs under normal vision prior to the cut. No single blade shall

49、be used fornotching more than 20 test specimens.9.4 Test specimens are loaded at various percentages of their room temperature yield stress. yield stress, measured per TestMethod D6693/D6693M. The applied stress levels should range from approximately 20 to 65 % at maximum increments of 5 %.Three specimens are tested at each stress level to produce statistically significant results.NOTE 11To develop the entire curve in a single direction at the recommended values listed above will require ten increments at three specimens each,or 30 indivi