1、Designation: D5641 94 (Reapproved 2011)Standard Practice forGeomembrane Seam Evaluation by Vacuum Chamber1This standard is issued under the fixed designation D5641; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last r
2、evision. 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 procedures to perform nondestruc-tive quality control testing described in Practice D4437 andD4545 for
3、evaluating the continuity of all types of geomem-brane seams using the bubble emission or vacuum chambermethod.1.2 The technique described in this practice is intended foruse on geomembrane seams, patches, and defects.1.3 The values stated in SI units are to be regarded asstandard. The values given
4、in parentheses 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 l
5、imitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D4437 Practice for Non-destructive Testing (NDT) for De-termining the Integrity of Seams Used in Joining FlexiblePolymeric Sheet GeomembranesD4439 Terminology for GeosyntheticsD4545 Practice for Determining the Integrity of FactorySe
6、ams Used in Joining Manufactured Flexible SheetGeomembranes3E515 Test Method for Leaks Using Bubble Emission Tech-niques2.2 E.P.A. Documents:EPA/530/SW-91/051 Inspection Techniques for the Fabrica-tion of Geomembrane Field Seams43. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1
7、geomembrane, nan essentially impermeable geo-synthetic composed of one or more synthetic sheets. (SeeTerminology D4439).3.1.2 seam, nthe connection of two or more pieces ofmaterial by mechanical, chemical, or fusion methods to pro-vide the integrity of a single piece of the material.3.1.3 vacuum cha
8、mber, na device that allows a vacuum tobe applied to a surface.3.1.3.1 DiscussionIn geomembranes, typical seamswould include adhesive bonded, bodied chemical fusion welds;chemical fusion welds; dielectric; dual hot wedge; fillet extru-sion; flat extrusion; hot air; single hot wedge; and ultrasonic.(
9、See EPA/530/SW-91/051.)NOTE 1For definition of other terms used in this practice, refer toTerminology D4439.4. Summary of Practice4.1 The basic principle of this practice consists of creating apressure differential across a seam and observing for bubbles ina film of foaming solution over the low pre
10、ssure side, withinthe vacuum chamber. The vacuum chamber has a viewing portthat allows observation of the seam area being tested. Thefoaming solution is applied to the surface to be tested and thevacuum chamber is placed over the test area. As the chamberis held firmly in place, vacuum is applied. A
11、ir leakage throughflaws in the test area cause bubbles in the foaming solution thatmay be observed.5. Significance and Use5.1 This practice is a nondestructive evaluation intended tobe used for quality control purposes during factory or fieldseaming of geomembranes.5.2 This practice may also be used
12、 to evaluate geomem-brane panels for holes that penetrate the entire thickness ofmaterial. Limitations on the test practice are that it may not besuitable for uneven or curved surfaces, thick seams, seams incorners, and thin extensible geomembranes.1This practice is under the jurisdiction of ASTM Co
13、mmittee D35 on Geosyn-thetics and is the direct responsibility of Subcommittee D35.10 on Geomembranes.Current edition approved June 1, 2011. Published July 2011. Originally approvedin 1994. Last previous edition approved in 2006 as D5641 94 (2006). DOI:10.1520/D5641-94R11.2For referenced ASTM standa
14、rds, 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 version of this historical standard is referencedon www.as
15、tm.org.4Available from the Superintendent of Documents, U.S. Government PrintingOffice, Washington, DC 20402.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Apparatus6.1 Vacuum PumpThe vacuum pump shall be fuel orelectric powered
16、and capable of sustaining the requiredvacuum for the duration of the test.6.2 Vacuum GaugeThe vacuum gauge shall be capable ofregistering, as a minimum, to 70 kPa (10 psi) in increments of5 kpa (34 psi).6.3 Calibration and AdjustmentThe calibration of thevacuum gauge shall be checked and adjusted pe
17、riodically, androutinely at a minimum of once every twelve months.6.4 Foaming SolutionThe foaming solution shall be pre-mixed with water at a ratio conducive to the formation ofbubbles. It shall be dispensed by spray, brush, or any otherconvenient means. The foaming solution shall be compatiblewith
18、the geomembrane.NOTE 2If the component to be tested has parts made of polyethyleneor structural plastics, the test fluid must not promote environmental stresscracking (E.S.C.). (See Test Method E515.)6.5 Vacuum ChamberThe vacuum chamber shall have anopen bottom and a clear viewing panel on top. It s
19、hall be anappropriate and convenient size and shape, made of rigidmaterials and equipped with a vacuum gauge, valve, and softpliable gasket around the periphery of the open bottom (seeFig. 1).NOTE 3Vacuum chamber equipment may be obtained from thesuppliers given in Footnote 5.5These suppliers are ci
20、ted only forconvenience and no commercial endorsement is expressed or implied byincorporation into this practice.7. Procedure7.1 The area of the seam to be evaluated should be clean andfree of soil or foreign objects that might prohibit a good sealfrom being formed between the vacuum chamber and the
21、geomembrane.7.2 Energize the vacuum pump.7.3 Wet an area immediately adjacent to and including thegeomembrane seam or test area measuring approximatelytwice the width and length of the vacuum chamber with afoaming solution.7.4 Place the vacuum chamber over the wet area of thegeomembrane such that th
22、e gasket is in complete contact withthe geomembrane surface, and the test area is centered underthe viewing port.7.5 Apply a normal force to the top of the vacuum chamberto effect a seal and open the vacuum valve.7.6 Ensure that a leak tight seal is created between thevacuum chamber gasket and the g
23、eomembrane material. Formost cases, a minimum vacuum of 28 to 55 kPa (4 to 8 psi) asregistered on the vacuum gauge should be appropriate.7.7 With the vacuum applied, maintain the normal force andobserve the geomembrane seam or test area through theviewing port for bubbles resulting from the flow of
24、air throughdefects in the seam. The vacuum should be held over the testsite for a duration of not less than 10 s. If the vacuum cannotbe held for the minimum 10 s, the test area shall be marked asuntested. It is essential that the viewing port remain clean at alltimes to facilitate unobstructed view
25、ing.7.8 If bubbles appear on the geomembrane seam, turn thethree-way vacuum valve to vent the chamber and remove thevacuum chamber from the seam. The defective area shouldthen be marked for repair.7.9 If bubbles do not appear through the geomembraneseam within the specified dwell time, turn the vacu
26、um valve tovent the chamber and remove the chamber from the seam.7.10 Move the vacuum chamber to the adjoining portion ofthe seam or test area overlapping the previously tested area bya distance no less than 10 % of the minimum chamber lengthor at least 50 mm (2 in.), whichever is the greater and re
27、peat theprocedure until the entire seam has been tested.8. Report8.1 Report the following information:8.1.1 Identification of the geomembrane material, includingtype of polymer, source, thickness, reinforced or nonreinforcedsheeting, seaming system used, ambient temperature, seamtested, seam width,
28、date of seam fabrication, and date of seamevaluation, and results of seam evaluation,NOTE 4The intent of the form is not to imply that each VCT is to berecorded on said form.8.1.2 Documentation of the typical vacuum pressure andhold duration and latest pressure gauge calibrations,8.1.3 Identificatio
29、n of the location and approximate size ofall defective areas, and8.1.4 Identification of foaming solution used for the test andif different types were used, the location of use for each type.5Series A100 Straight Seam Tester supplied by the American Parts and ServiceCompany, 2201 West Commonwealth A
30、venue, P.O. Box 702, Alhambra, CA 91802.Vacuum Chamber Test System as supplied by Sinclair Equipment Company, 6686A Merchandise Way, Diamond Springs, CA 95619. Columbine International, Ltd.,5441 Merchant Circle, Placerville, CA 95667.FIG. 1 Vacuum ChamberD5641 94 (2011)29. Keywords9.1 bubble emissio
31、n testing; geomembrane; nondestructivetesting; seam; testing; vacuum; vacuum chamberAPPENDIX(Nonmandatory Information)X1. Evaluation FormFIG. X1.1 Evaluation FormD5641 94 (2011)3ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item men
32、tionedin 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 responsibility.This standard is subject to revision at any time by the responsible technical committee
33、 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 addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meetin
34、g 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 International, 100 Barr Harbor Drive, PO
35、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/).D5641 94 (2011)4
