ASTM D5199-2011 Standard Test Method for Measuring the Nominal Thickness of Geosynthetics《测定土木织物和地膜的标定厚度的标准试验方法》.pdf

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1、Designation: D5199 11Standard Test Method forMeasuring the Nominal Thickness of Geosynthetics1This standard is issued under the fixed designation D5199; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A n

2、umber 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 the nominalthickness of geotextiles, smooth surfaced geomembranes, geo-nets, and geocomposite

3、 drainage products.1.2 This test method does not provide thickness values forgeosynthetics under variable normal compressive stresses. Thistest method determines nominal thickness, not necessarilyminimum thickness.1.3 The values stated in SI units are to be regarded asstandard. The values given in p

4、arentheses are for informationonly.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-priate safety and health practices and determine the applica-bility of regulatory limit

5、ations prior to use.2. Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD1776 Practice for Conditioning and Testing TextilesD2905 Practice for Statements on Number of Specimens forTextiles3D4354 Practice for Sampling of Geosynthetics for TestingD4439 Terminology for Geosy

6、ntheticsD5199 Test Method for Measuring the Nominal Thicknessof GeosyntheticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 For definitions of other terms relating to geotextiles andgeomembranes used in this standard, refer to Termin

7、ologyD4439. For definition of other textile terms used in thisstandard, refer to Terminology D123.3.2 Definitions:3.2.1 pressure, nthe force or load per unit area.3.2.2 thickness(1) the distance between one planar sur-face and its opposite parallel and planar surface; (2) in thetextiles the distance

8、 between the upper and lower surfaces ofthe material, measured under a specified pressure and time.4. Summary of Test Method4.1 The nominal thicknesses of geosynthetics is determinedby observing the perpendicular distance that a movable plane isdisplaced from a parallel surface by the geotextile or

9、geomem-brane material while under a specified pressure (2 kPa forgeotextiles and 20 kPa for geomembranes for 5 s).5. Significance and Use5.1 Thickness is one of the basic physical properties used tocontrol the quality of many geosynthetics. Thickness values arerequired in calculation of some geotext

10、ile and geomembraneparameters such as permeability coefficients, tensile stress(index), and the like thickness is not indicative of fieldperformance and therefore is not recommended for specifica-tions.5.2 The thickness of geotextiles and geomembranes mayvary considerably depending on the pressure a

11、pplied to thespecimen during measurement. Where observed changes occur,thickness decreases when applied pressure is increased. Tominimize variation, specific sample size and applied pressureare indicated in this method to ensure all results are compa-rable.5.3 To determine the effect of difference p

12、ressure loadingson the measure thickness of geotextiles and geomembranes,use this test method.5.4 This test method may be used for acceptance testing ofcommercial shipments of geotextiles and geomembranes, butcaution is advised since information on between-laboratoryprecision is incomplete. Comparat

13、ive tests, as directed in 5.4.1may be advisable.5.4.1 In case of a dispute arising from differences inreported test results when using this test method for acceptancetesting of commercial shipments, the purchaser and the sup-plier should conduct comparative tests to determine if there is1This test m

14、ethod is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.03 on Perme-ability and Filtration.Current edition approved Feb. 1, 2011. Published March 2011. Originallyapproved in 1991. Last previous edition approved in 2006 as D5199 01(20

15、06).DOI: 10.1520/D5199-11.2For 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.3Withdrawn. The last approved versi

16、on of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.a statistical bias between their laboratories. Competent statis-tical assistance is recommended for the investigation of bias

17、.As a minimum, the two parties should take a group of testspecimens that are as homogeneous as possible and that areformed from a lot of material of the type in question. The testspecimens should be randomly assigned in equal numbers toeach laboratory for testing. The average results from the twolab

18、oratories should be compared using Students t-test forunpaired data and an acceptable probability level chosen by thetwo parties before the testing is begun. If bias is found, eitherits cause must be found and corrected or the purchaser andsupplier must agree to interpret future tests in the light o

19、f theknown bias.NOTE 1The user should be aware that the compressibility of thematerials, their rebound characteristics, and the like will also affect thethickness of the geotextiles and geomembranes following the time whenthey are rolled up on rolls shipped and stored.6. Apparatus6.1 Thickness Testi

20、ng Instrument The thickness gaugeshall have a base (or anvil) and a free moving presser foot platewhose planar faces are parallel to each other to 0.01 mm. Agauge with a 56.4 mm (2.22 in.) diameter presser foot, the baseshall extend at least 10 mm in all directions further than theedge of the 2500 m

21、m2circular pressor foot, shall be used formeasurements of geotextiles, geocomposite drainage materials,and geonets. A gauge with a 6.35 mm (0.250 in.) diameterpressor foot shall be used for laboratory measurements ofgeomembranes. A gauge with 6.35 mm (0.250 in.) diameterpressor foot and base may be

22、used for field measurements ofgeomembrane thickness. The instruments must be capable ofmeasuring a maximum thickness of at least 10 mm to anaccuracy of at least 60.02 mm. The gauges shall be con-structed to permit gradual application of pressure to a specificforce of 2 6 0.02 kPa (0.29 6 0.003 psi)

23、for geotextiles and20 6 0.2 kPa (2.9 6 0.03 psi) for geomembranes. Dead-weightloading may be used.6.1.1 The specified force of 20 kPa may be inadequate forsome HDPE geomembranes. A pressure in the range of 50 to200 kPa is recommended for HDPE geomembranes if ficti-tiously high readings are suspected

24、 using the 20 kPa pressure.NOTE 2(Appendix X1) lists some of the suppliers of apparatus forthickness measurement.6.2 Cutting DiesDies to cut specimens should have di-mensions at least as large as a circle of 75 mm (3 in.) diameter.NOTE 3Due to compressibility of many geotextiles and geomem-branes th

25、e cutting and handling preparation may change the thickness.Care should be exercised to minimize these effects.7. Sampling7.1 Lot SampleIn the absence of other guidelines dividethe product into lots and take lot samples as specified inPractice D4354.7.2 Laboratory SampleConsider the units in the lot

26、sample 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 7.3-7.5.2can be met. Exclude the inner and outer wraps of the roll or anymaterial containing folds, crushed areas or

27、other distortions notrepresentative of the sampled lot.7.3 Remove test specimens from the laboratory sample in arandomly distributed pattern across the width with no specimentaken nearer than 100 mm (4 in.) from the selvage or roll edge,unless otherwise specified. For geomembranes include at leaston

28、e specimen taken no more than 152 mm (6 in.) from theedge. Since seams are an important part of geomembraneapplications, thickness readings within 152 mm (6 in.) of eachedge is appropriate.7.4 Test SpecimensFrom each unit in the laboratorysample, remove the specimens so that the edge of the specimen

29、will extend beyond the edge of the pressor foot by 10 mm (0.39in.) in all directions (that is, at least a circle of 75 mm (3 in.)in diameter).7.5 Number of SpecimensUnless otherwise agreed upon,as when provided in an applicable material specifications, takea number of test specimens per laboratory s

30、ample such that theuser may expect at the 95 % probability level that the test resultis not more than 6.0 % of the average above or below the trueaverage of the sample. Determine the number of specimens persample as follows:7.5.1 Reliable Estimate of vWhen there is a reliableestimate of v based upon

31、 extensive part records for similarmaterials tested in the users laboratory as directed in themethod, calculate the required number of specimens for themachine and cross-machine directions as follows:n 5 tv / A!2where:n = number of test specimens (rounded upward to a wholenumber),v = reliable estima

32、te of the coefficient of variation ofindividual observations on similar materials in theusers laboratory under conditions of single-operationprecision, %,t = the value of Students t for two-sided limits (see Table1), a 95 % probability level, and the degrees offreedom associated with the estimate of

33、 v, andA = 5.0 % of the average, the value of the allowablevariation.TABLE 1 Values of Students t for Two-Sided Limits and the95 % ProbabilityAdf t.025 df t.025 df t.0251 12.706 11 2.201 21 2.0802 4.303 12 2.179 22 2.0743 3.182 13 2.160 23 2.0694 2.776 14 2.145 24 2.0645 2.571 15 2.131 25 2.0606 2.4

34、47 16 2.120 26 2.0567 2.365 17 2.110 27 2.0528 2.306 18 2.101 28 2.0489 2.262 19 2.093 29 2.04510 2.228 20 2.086 inf. 1.960AValues in this table were calculated using Hewlett Packard HP 67/97 UsersLibrary Programs 03848D, “One-Sided and Two-Sided Critical Values of Studentst” and 00350D, “Improved N

35、ormal and Inverse Distribution.” For values at otherthan the 95 % probability level, see published tables of critical values of Studentst in any standard statistical text. Further use of this table is defined in PracticeD2905.D5199 1127.5.2 No Reliable Estimate of vWhen there is no reliableestimate

36、of v for the users laboratory, Eq 1 should not be useddirectly. Instead, specify the fixed number (10) of specimens.The number of specimens is calculated using v = 9.5 % of theaverage. These values for v are somewhat larger than usuallyfound in practice. When a reliable estimate of v for the usersla

37、boratory becomes available, Eq 1 will usually require fewerthan the fixed number of specimens.8. Conditioning8.1 Bring the specimens to moisture equilibrium in theatmosphere for testing geotextiles and geomembranes, that is,temperature of 21 6 2C (70 6 4F) and relative humidity of60 6 10 %.8.2 Moist

38、ure Equilibrium is considered to have beenreached when the increase in mass of the specimen, insuccessive weighings made at intervals of not less than 2 h,does not exceed 0.1 % of the mass of the specimen. In general,many geotextiles and geomembranes contain more moisturewhen received than they will

39、 after reaching moisture equilib-rium.NOTE 4It is recognized that in practice, geotextiles and geomem-branes are frequently not weighed to determine when moisture equilib-rium has been reached. While such a method cannot be accepted in casesof dispute, it may be sufficient in routine testing for a r

40、easonable period oftime before the specimens are tested.Atime of at least 24 h has been foundacceptable in most cases. However, fibers may contain more moistureupon receipt than after conditioning and lose moisture relatively slowlyduring conditioning. When this is known, a preconditioning cycle, as

41、described in Practice D1776, may be agreed upon by the contractualparties for routine testing.9. Procedure9.1 Test the conditioned specimens in the standard atmo-sphere specified in 8.1.9.2 Handle the test specimens carefully to avoid altering thenatural state of the material.9.3 Procedure A - Geote

42、xtiles, Geocomposite DrainageMaterials, and Geonets: With the force applied to the pressorfoot on the base (no test specimen present), zero the measuringscale or record the “base reading.” Lift the presser foot, centerthe test specimen on the base under the presser foot, and bringthe presser foot in

43、to contact with the material. Graduallyincrease the pressure to 2 kPa (0.29 psi).After the full force hasbeen applied to presser foot for 5 s against the specimen, recordthe thickness value to the nearest 0.02 mm and remove thespecimen from the test device.9.4 Procedure B - Smooth Surfaced Geomembra

44、nes: Withthe force applied to the pressor foot on the base (no testspecimen present), zero the measuring scale or record the “basereading.” Lift the presser foot, center the specimen on the baseunder the presser foot, and bring the presser foot into contactwith the material. Gradually increase the p

45、ressure to 20 kPa(2.9 psi). After the full force has been applied to presser footfor 5 s against the specimen, record the thickness value to thenearest 0.02 mm and remove the specimen from the test device.10. Calculation10.1 Calculate the average of the thickness for all testresults as read directly

46、 from the test instrument.11. Report11.1 The report for the nominal thickness shall include thefollowing information:11.1.1 Project, type of geotextile or geomembranes tested,and method of sampling.11.1.2 Name or description of thickness apparatus used fortesting.11.1.3 Dimensions of the presser foo

47、t and of the specimen.11.1.4 Loading time interval.11.1.5 Number of tests.11.1.6 Average nominal thickness, and11.1.7 Coefficient of variation of thickness in the sample, inpercent (optional).11.1.8 Any unusual or out of standard conditions or obser-vations made during the tests.12. Precision and Bi

48、as12.1 Precision (Geotextiles):12.1.1 Inter-Laboratory Test Program4An inter-laboratory study of Test Method D5199 was performed in1994. Each of six laboratories tested ten randomly drawnspecimens from each of four materials.12.1.2 ResultThe precision information given below hasbeen calculated for t

49、he comparison of six test results, each ofwhich is the average of ten specimens. Four different materialswere tested.12.1.3 95 % Repeatability Limit The repeatability limit is14 % of the test results. For the different materials, therepeatability limits range from 22 % to 9 %.12.1.4 95 % Reproducibility Limit (Between Laboratory)The reproducibility limit is 23 % of the test results. For thedifferent materials, the repeatability limits range from 33 % to17 %.12.1.5 The respective coefficients of variation percentagesfor the test results may be obtained