1、Designation: D5820 95 (Reapproved 2018)Standard Practice forPressurized Air Channel Evaluation of Dual-SeamedGeomembranes1This standard is issued under the fixed designation D5820; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, th
2、e 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 a nondestructive evaluation of thecontinuity of parallel geomembrane seams separated by
3、 anunwelded air channel. The unwelded air channel between thetwo distinct seamed regions is sealed and inflated with air to apredetermined pressure. Long lengths of seam can be evaluatedby this practice more quickly than by other common nonde-structive tests.1.2 This practice should not be used as a
4、 substitute fordestructive testing. Used in conjunction with destructivetesting, this method can provide additional information regard-ing the seams undergoing testing.1.3 This practice supercedes Practice D4437/D4437M forgeomembrane seams that include an air channel. PracticeD4437/D4437M may contin
5、ue to be used for other types ofseams. The user is referred to the referenced standards, or toEPA/530/SW-91/051 for additional information regardinggeomembrane seaming techniques and construction qualityassurance.1.4 This standard does not purport to address all of thesafety concerns, if any, associ
6、ated 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.1.5 This international standard was developed in accor-dance with internationally reco
7、gnized 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. Referenced Documents2.1 ASTM Standards:2D4437/D4437M Practic
8、e for Nondestructive Testing (NDT)for Determining the Integrity of Seams Used in JoiningFlexible Polymeric Sheet GeomembranesD4439 Terminology for GeosyntheticsD4491/D4491M Test Methods for Water Permeability ofGeotextiles by Permittivity2.2 EPA Standard:3EPA/530/SW-91/051 Technical Guidance Documen
9、t: In-spection Techniques for the Fabrication of GeomembraneField Seams3. Terminology3.1 Definitions:3.1.1 dual seam, na geomembrane seam with two parallelwelded zones separated by an unwelded air space.3.1.2 DiscussionThe dual seam itself can be made by anumber of methods, the most common being the
10、 hot wedgetechnique. Other possible methods include hot air and ultra-sonic bonding techniques.3.1.3 geomembrane, nan essentially impermeable geosyn-thetic composed of one or more synthetic sheets.3.1.4 DiscussionIn geotechnical engineering, “imperme-able” essentially means that no measurable liquid
11、 flowsthrough a geosynthetic when tested in accordance with TestMethods D4491/D4491M.3.1.5 seam, na permanent joining of two or more materi-als.3.2 For definitions of other terms, see Terminology D4439.4. Summary of Practice4.1 This practice utilizes a dual seam where an air channelexists between th
12、e two welded zones. Both ends of the air1This practice is under the jurisdiction of ASTM Committee D35 on Geosyn-thetics and is the direct responsibility of Subcommittee D35.10 on Geomembranes.Current edition approved Feb. 1, 2018. Published February 2018. Originallyapproved in 1995. Last previous e
13、dition approved in 2011 as D5820 95 (2011).DOI: 10.1520/D5820-95R18.2For 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 w
14、ebsite.3Available from the Superintendent of Documents, U. S. Government PrintingOffice, Washington, DC 20402.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
15、recognized 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.1channel are sealed and then a pressure gauge is attached to
16、 theair space.Air pressure is applied and the gauge is monitored forexcessive gauge air pressure drop.4.2 Air pressures used in this practice are related to thethickness, stiffness, and material type of the geomembrane.4.3 The minimum monitoring time is recommended to be2 min following stabilization
17、 of the pressure.4.4 Maximum allowable loss of air pressure varies depend-ing upon thickness, stiffness, and type of material of thegeomembrane.5. Significance and Use5.1 The increased use of geomembranes as barrier materialsto restrict liquid or gas movement, and the common use ofdual-track seams i
18、n joining these sheets, has created a need fora standard nondestructive test by which the quality of theseams can be assessed for continuity and watertightness. Thetest is not intended to provide any indication of the physicalstrength of the seam.5.2 This practice recommends an air pressure test wit
19、hin thechannel created between dual-seamed tracks whereby thepresence of unbonded sections or channels, voids,nonhomogenities, discontinuities, foreign objects, and the like,in the seamed region can be identified.5.3 This technique is intended for use on seams betweengeomembrane sheets formulated fr
20、om the appropriate poly-mers and compounding ingredients to form a plastic orelastomer sheet material that meets all specified requirementsfor the end use of the product.6. Equipment6.1 Sealing Equipment, appropriate to seal the two ends ofthe air channel.6.2 A device is necessary to insert air into
21、 the open channeland to allow monitoring of its pressure.NOTE 1A sharp, hollow needle attached to a properly functioningpressure gauge has been used successfully. Other devices may provideequivalent functions.6.3 Air Pump, either manual or motor driven, capable ofgenerating up to 350 kPa (50 lb/in.2
22、) pressure is necessary. Itmust be placed on an adequate cushion to preclude damage tothe geomembrane. A flexible hose is used to connect the pumpto the air pressure device. This hose should have a quickconnect on its end for disengagement after pressure is suppliedto its desired value, that is, the
23、 pump is not to be attached whilethe air pressure is being monitored.6.4 Knife, capable of cutting or trimming the liner material.NOTE 2A hook-bladed knife is recommended. Straight-bladed knivesmay damage the geomembrane by cutting through the material beingtrimmed and into the underlying geomembran
24、e.6.5 Pressure Gauge, capable of indicating the air pressure in7 kPa (1 lb/in.2) within the test range.NOTE 3The gauge should be calibrated as specified by themanufacturer, or at a frequency of at least once per year.7. Procedure7.1 After the dual-track seam is fabricated and the length ofseam that
25、is to be evaluated is determined, seal off the two endsof the continuous air channel.7.2 Connect the pressure gauge directly to the air channel.7.3 Connect an air pump to the pressure gauge with aflexible hose via a quick connect and pressurize the air channelto the pressure appropriate for the geom
26、embrane type.7.4 Remove the flexible hose that connects the air channelto the pressure gauge. Following pressure stabilization, observethe air pressure gauge for the desired test time. The test timeshould be a minimum of 2 min. Mark the time and pressure ofthe beginning and end of the test on the ge
27、omembrane with avisible marker. The maximum allowable pressure drop may becompared to the maximum allowable value.7.5 If the pressure does not drop below the maximumallowable value after the specified test period, open the airchannel at the end away from the pressure gauge. Air shouldrush out and th
28、e pressure gauge should register an immediatedrop in pressure, indicating that the entire length of the seamhas been tested. If this does not happen, either the air channelis blocked or the equipment is faulty, and the test is not valid.Attempt to locate the problem and retest the seam in accor-danc
29、e with the project specifications.7.6 If the pressure drop is greater than the maximumallowable value after the test period, check the end seals of theair channel. Reseal these areas if a leak is noticed and thenrepeat the entire test.NOTE 4Leaks around the end seals and air pressure device can usua
30、llybe located by putting moisture around the suspected area and looking forbubbles.7.7 If significant changes in geomembrane temperatureoccur during pressure testing (for example, cloud cover orother shading), a variation in channel pressure may be recordeddue to expansion or contraction of the air
31、channel. If anincrease or decrease in temperature is suspected of havingcaused a pressure variation, repeat the test after the geomem-brane temperature has stabilized.7.8 Any dual seam that cannot be successfully tested usingthis practice should be marked and tested using anothernondestructive testi
32、ng practice, when possible.8. Report8.1 The report of a pressurized dual seam test is usuallygiven in the form of a completed chart. It should include thefollowing information at a minimum:8.1.1 Data of test,8.1.2 Time of test,8.1.3 Temperature at time of test,8.1.4 Location of test with respect to
33、panel layout plan,8.1.5 Stabilized air channel pressure,8.1.6 Duration of test time,8.1.7 Gauge pressure drop during test,8.1.8 Outcome of test (pass/fail/retest), and8.1.9 If failremedial action is described in detail.D5820 95 (2018)28.2 A form as shown in Fig. 1 includes the above informa-tion and
34、 may be used for such reporting.9. Precision and Bias9.1 The precision of this test has not been established.9.2 The threshold value for accepting seam quality is thatvalue agreed upon by all parties overseeing the installation ofthe project and is thus the source of bias in this procedure.ASTM Inte
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37、uld be addressed to ASTM International Headquarters. Your comments will receive 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 Sta
38、ndards, at the address shown below.This standard is copyrighted by ASTM International, 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
39、-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:/ 1 Report Form for Pressurized Air Channel Test for Dual-Seamed GeomembranesD5820 95 (2018)3
