1、Designation: D6365 99 (Reapproved 2018)Standard Practice forNondestructive Testing of Geomembrane Seams Using theSpark Test1This standard is issued under the fixed designation D6365; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、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 practice covers the nondestructive testing of fieldseams in geomembranes using the spark test. A susp
3、ect area isindicated by the generation of a spark. The test is applicable toseams made by the extrusion method, seams made by usingwelding tape (a strip of the same type of material as thegeomembrane, that is welded over adjacent sections ofgeomembrane to create a seam), or seams where it is practic
4、alto insert a conductive material in the seam just prior to orduring fabrication.1.2 The spark test may produce an electrical spark andtherefore can only be used where an electrical spark would notcreate a hazard.1.3 Unless the voltages and distances prescribed are care-fully adhered to, a “false po
5、sitive” indication may result. Thisfalse positive occurs when the arc distance is too large for thevoltage applied at the time and conditions of testing.1.4 The values stated in SI units are to be regarded asstandard. The values given in parentheses are for informationonly.1.5 This standard does not
6、 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, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.6 This international st
7、andard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2.
8、 Referenced Documents2.1 ASTM Standards:2D4439 Terminology for GeosyntheticsD4491/D4491M Test Methods for Water Permeability ofGeotextiles by Permittivity3. Terminology3.1 Definitions:3.1.1 geomembrane, nan essentially impermeable geosyn-thetic composed of one or more synthetic sheets.3.1.1.1 Discus
9、sionIn geotechnical engineering, “essen-tially impermeable” means that no measurable liquid flowsthrough a geosynthetic when tested in accordance with TestMethods D4491/D4491M.3.1.2 seam, na permanent joining of two or more materi-als.3.2 For definitions of other terms, see Terminology D4439.4. Summ
10、ary of Practice4.1 To use this practice, a conductive material is insertedinto the field seam just prior to or during fabrication. Theconductive material in the seam is connected to the negativeterminal of the test apparatus, and a positive voltage is appliedacross the seam edge.Asuspect area in the
11、 seam is indicated bya spark from the voltage source to the conductive material.5. Significance and Use5.1 Spark testing of geomembrane field seams is particu-larly useful in locations where other nondestructive test meth-ods are not practical, for example in tight corners or acircumferential seam a
12、round a pipe.6. Apparatus6.1 The test apparatus consists of a high-voltage, low-current source with a negative terminal for ground and a1This practice is under the jurisdiction of ASTM Committee D35 on Geosyn-thetics and is the direct responsibility of Subcommittee D35.10 on Geomembranes.Current edi
13、tion approved Feb. 1, 2018. Published February 2018. Originallyapproved in 1999. Last previous edition approved in 2011 as D6365 99 (2011).DOI: 10.1520/D6365-99R18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Boo
14、k 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 accordance with internationally recogni
15、zed 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.1positive terminal for a voltage applicator. A voltage applicatorma
16、y consist of a handle and wire brush, conductive neoprenesqueegee, or other suitable applicator.6.2 The range of the high voltage source is typically 20 000to 35 000 V.6.2.1 The voltage required to cause a discharge (spark)between the positive electrode and the negative electrode wireis expressed by
17、 the formula:V 5 K=D (1)where:V = test voltage,K = a constant (V/(mm)1/2), andD = the distance from the edge of the extrusion bead on thelower panel to the conductive material, in mm.6.2.2 If the voltage is not adequate due to underestimatingD, a false positive test (a seam with a suspect area resul
18、ting inno spark and testing as a good seam) may result.6.2.3 Good results have been obtained using the test volt-ages and distances given in Table 1.6.2.4 The conductive material should be located 8 to 15 mmfrom the edge of the extrusion bead on the bottom geomem-brane to be a successful test.7. Pro
19、cedure7.1 Before or as the seam is fabricated, a continuouselectrically conductive material is inserted in the lapped area ofthe panels 2 to 5 mm (0.1 to 0.2 in.) from the edge of the toppanel of membrane. See Fig. 1.7.2 Prior to testing, it is necessary to connect the conductivematerial installed i
20、n the field seam to the negative terminal ofthe voltage source or a separate ground.7.3 Set the voltage source to a voltage needed for theexpected distance. Typical distances and the required voltagesare given in Table 1. The user should verify the test voltage isadequate using a trial seam with a s
21、imulated defect prior totesting and also to verify that the test voltage will not damagethe geomembrane.7.4 Check that the field seams and areas adjacent to theseams are dry prior to testing.7.5 Place the voltage applicator (such as a wire brush orconductive neoprene squeegee) connected to the posit
22、iveterminal of the voltage source, in contact with the geomem-brane at the seam.7.6 Move the voltage applicator along the seam at a uniformrate of 6 to 9 m per minute. The voltage applicator must makeintimate contact with the seam being inspected.7.7 As the test progresses, the generation of a spark
23、 indi-cates a suspect area in the seam. It is desirable that equipmenthas an audible tone signal that occurs when a spark isgenerated.7.8 The suspect area is marked for repair.8. Report8.1 Report the following information:8.1.1 Identification of the geomembrane material, includingthe type of polymer
24、, manufacturer, thickness, reinforced ornonreinforced sheeting, seam type used, ambient temperature,date of seam fabrication, date of seam evaluation, seam tested,and results of seam evaluation.8.1.2 Voltage used.9. Keywords9.1 geomembrane; nondestructive; seams; testingTABLE 1 Test Voltage for Vari
25、ous Expected DistancesAExpected Distance D Test Voltage(in.) (mm) (V)0.250 6 20 0000.375 10 25 0000.500 13 28 0000.625 16 31 0000.750 19 35 000AConstant K = 7900 volts/(mm)1/2.D6365 99 (2018)2FIG.1D6365 99 (2018)3ASTM International takes no position respecting the validity of any patent rights asser
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28、e 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 the address shown below.This standard is copyrighted by ASTM Intern
29、ational, 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 Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 99 (2018)4
