ASTM D7466-2008 895 Standard Test Method for Measuring the Asperity Height of Textured Geomembrane.pdf

1、Designation: D 7466 08Standard Test Method forMeasuring the Asperity Height of Textured Geomembrane1This standard is issued under the fixed designation D 7466; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisi

2、on. 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 TThis test method covers a procedure to measure theasperity height of textured geomembranes.1.2 This test method does not provide

3、 for measurement ofthe spacing between the asperities nor of the complete profileof the textured surface.1.3 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

4、 health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 4439 Terminology for GeosyntheticsD 5994 Test Method for Measuring Core Thickness ofTextured Geomembrane3. Terminology3.1 Definitions:3.1.1 asperity, nthe individual

5、 projections of polyethyl-ene that extend above the core surface of a textured geomem-brane resulting in the textured surface profile.3.1.2 core thickness, nthe average thickness of a texturedgeomembrane as measured using Test Method D 5994.3.1.3 geomembrane), nan essentially impermeable geo-synthet

6、ic composed of one or more synthetic sheets. D 44393.1.4 thickness gage contact point, nthe tip of a thicknessgage which contacts the base sheet of the geomembranesurface.3.1.5 setting block, nthe component part of a depth gagethat rests on top of the asperities.3.1.6 thickness, n the perpendicular

7、distance between onesurface and its opposite.3.2 For definitions of other terms used in this test method,refer to Terminology D 4439.4. Summary of Test Method4.1 The asperity height of a textured geomembrane ismeasured with a depth gage, the setting block of which rests onthe top of the asperities w

8、hile the contact point extends to thesheets core surface.4.2 The asperity height of a textured geomembrane iscalculated as the average value of ten (10) individual measure-ments taken across the roll width of the sample under investi-gation.5. Significance and Use5.1 The asperity height is an index

9、property used to quantifyone of the physical attributes related to the surface roughnessof textured geomembranes.5.2 This test method is applicable to all currently availabletextured geomembranes that are deployed as manufacturedgeomembrane sheets.6. Apparatus6.1 Depth Gage The depth gage shall cons

10、ist of threecomponents that conform the requirements of this section; adial indicator, a setting block and a contact point with exten-sion.6.1.1 Dial Indicator capable of measuring to depth of atleast 2.5 mm (0.10 in.) with an accuracy of 60.025 mm (0.001in.).6.1.2 Setting Blockthe setting block sha

11、ll have a basedimension of 50 mm to 63.5 mm long x 20 mm to 12.7 mmwide (2.0 in. to 2.5 in long x 0.75 in. to 0.50 in wide) and aheight of 15 mm (0.60 in.)6.1.3 Contact Point with Extension The contact point is1.3 mm (0.051 in.) in diameter with the tip tapered to a point.An extension of approximate

12、ly 17 mm (0.66 in.) is required toachieve the necessary travel beyond the base surface of thesetting block. The contact point should protrude at least 10 mmbelow the setting block when not in use in order to ensure thata competent “zero” setting is achieved. See Fig. 1, Fig. 2, andFig. 3.6.1.4 The m

13、ass of the depth gage fully assembled with thedial indicator, setting block, contact point with extensionshould not exceed 300 grams.NOTE 1Depth gages of the type described above are manufactured byChicago Dial Indicator, Inc., B.C. Ames Company and Federal Instru-ments.1This test method is under th

14、e jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.10 on Geomem-branes.Current edition approved July 1, 2008. Published August 2008.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at servicea

15、stm.org. For Annual 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.7. Sampling7.1 Sample For the sample, take a full width sam

16、ple atleast 75 mm (3-in.) wide. Exclude the inner and outer wraps ofthe roll or any material not representative of the sample. Eitherthe entire strip may be tested or individual test specimens maybe taken from this sample, with a minimum diameter of 75 mm(3-in), spaced such that a total of ten (10)

17、asperity heightdeterminations will be made approximately evenly across thesample.7.2 Sample LabelingFor textured geomembrane samplesthat are textured on both sides, identify one surface as “SideA”and the other as “Side B”. Side A should correspond to theoutside surface of the product when on the par

18、ent roll, and SideB the inside surface whenever this relationship is known8. Conditioning and Testing8.1 Bring the specimens to temperature equilibrium at 21 62C (70 6 4F) and at a relative humidity of 60 6 10 %.9. Procedure9.1 Test the conditioned specimens in the standard labora-tory atmosphere sp

19、ecified in 8.1.9.2 Place the depth gage on a flat, rigid supporting surfaceto zero the contact point with the bottom of the setting block.9.3 Place the geomembrane specimen being tested on a flat,rigid, supporting surface being vigilant to keep the specimenflat for the measurements. For two side tex

20、tured geomem-branes, measure the asperity height of Side A first.9.4 Place the depth gage on the surface of the texturedgeomembrane specimen, with the long axis of the setting blockperpendicular to the machine direction of the roll. Do not toapply downward hand pressure on the gage as this wouldcomp

21、ress the asperities under the setting block. Allow thecontact point to come into contact with the “low spots” or“valleys”, in between the asperities, or into the indentations, ofthe textured surface(s). Move the depth gage slightly on the testspecimen to obtain the local maximum reading. Repeat thea

22、bove within a search radius of approximately 12 mm (0.5 in.)so that a total of three observations are obtained. Record thehighest value of the three observations to the nearest 0.025 mmor 0.001 in. as the asperity height determination.NOTE 2Be vigilant not to drag the extended contact point whilemov

23、ing the depth gage laterally across the sample between determinationsas this can result in damage to the contact point.NOTE 3The parent standard for this procedure, GRI GM-12 originallyspecified that the local highest asperity measurement is taken for eachasperity height determination. This is consi

24、stent with procedure fordetermining the thickness of a textured geomembrane in accordance withASTM D 5994, which specifies that the individual thickness determina-tions are taken where the “low spots” or “valleys” are the deepest.9.5 Repeat 11.1.1 above at the next position,9.6 Repeat 9.3 thru 9.5 o

25、n Side B for two side texturedgeomembrane samples.FIG. 1 The Asperity Height Test GageFIG. 2 Contact PointFIG. 3 Contact ExtensionD746608210. Calculation10.1 Calculate the average asperity height of the sample (thetest result) from the ten (10) individual asperity height deter-minations and record t

26、o the nearest 0.025 mm or 0.001 in.11. Report11.1 The report shall include the following:11.1.1 Project, type of geomembrane tested, and method ofsampling. 111.1.2 Name or description of depth gage used for testing.11.1.3 Number of specimens.11.1.4 Individual asperity height determinations to the ne

27、ar-est 0.025 mm or 0.001 in.11.1.5 Average asperity height to the nearest 0.025 mm or0.001 in.11.1.6 Coefficient of variation of the individual measure-ments of the sample, in percent (optional).11.1.7 Any unusual or out-of-standard conditions or obser-vations made during the tests12. Precision and

28、Bias12.1 PrecisionThe precision of this test method procedureis being established.12.2 BiasThe procedure in this test method has no biasbecause the value of asperity height can be defined only interms of this test method.13. Keywords13.1 asperity height; geomembrane; geosynthetics; texturedgeomembra

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