1、Designation: D 7177 05Standard Specification forAir Channel Evaluation of Polyvinyl Chloride (PVC) DualTrack Seamed Geomembranes1This standard is issued under the fixed designation D 7177; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revi
2、sion, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers a nondestructive evaluation ofthe strength and continuity of parallel PVC
3、 geomembraneseams separated by an unwelded air channel. The unwelded airchannel between the two distinct seamed regions is sealed andinflated with air to a predetermined pressure. Long lengths ofseam can be evaluated by this specification more quickly thanby other common nondestructive tests.1.2 Thi
4、s specification can be used as a substitute fordestructive testing or used in conjunction with destructivetesting.1.3 This specification covers PVC sheet 0.760 mm (0.030in.) and thicker.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is th
5、eresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 4439 Terminology for Geosynthetics3. Terminology3.1 Definitions:3.1.1 dual seam, na
6、geomembrane seam with two parallelwelded zones separated by an unwelded air space.3.1.1.1 DiscussionThe dual seam itself can be made by anumber of methods; hot wedge, hot air, and ultrasonic bondingare all typical techniques.3.1.2 geomembrane, nan essentially impermeable geo-synthetic composed of on
7、e or more synthetic sheets.3.1.3 seam, na permanent joining of two or more mate-rials.3.2 For definitions of other terms, see Terminology D 4439.4. Summary of Specification4.1 This specification utilizes a dual seam where an airchannel exists between the two welded zones. Both ends of theair channel
8、 are sealed and then a pressure gauge is attached tothe air space. Air pressure is applied and the gauge ismonitored.4.2 Air pressures used in this specification are related to theambient temperature of the PVC geomembrane and can beused for thickness 0.760 mm (0.030 in.) and thicker PVCgeomembrane.
9、 The air pressure is not dependant on thicknessof the PVC geomembrane being tested.4.3 The minimum monitoring time is recommended to be12min (30 s) following stabilization of the pressure.5. Significance and Use5.1 The increased use of geomembranes as barrier materialsto restrict liquid or gas movem
10、ent, and the common use of dualtrack seams in joining these sheets, has created a need for astandard nondestructive test by which the quality of the seamscan be assessed for continuity, water tightness, and strength.The test is also intended to provide an indication of thephysical peel strength of t
11、he PVC seam.5.2 This specification recommends an air pressure testwithin the channel created between dual seamed trackswhereby the presence of un-bonded sections or channels,voids, discontinuities, foreign objects, and the like, in theseamed region can be identified.1This specification is under the
12、jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.10 on Geomem-branes.Current edition approved August 15, 2005. Published September 2005.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serv
13、iceastm.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.5.3 This technique is intended for use on seams of PVCG
14、eomembrane sheets 0.760 mm (0.030 in.) and thicker formu-lated from the appropriate polymers and compounding ingre-dients to form a polyvinyl chloride sheet material that meets allspecified requirements for the end use of the product.5.4 This test is used to assure minimum peel strengths aremet thro
15、ugh the entire seam area.5.5 This test measures the seam strength to 2.6 kN/m (15lb/in. width minimum) peel strengths.5.6 This procedure is based on an air channel width of 15.876 3.17 mm (0.625 6 0.125 in.). For air channels greater orlesser in lay flat width use the formula below to calculate hoop
16、stress.5.7 Hoop Stress (Barlows Formula)The stress in a chan-nel wall acting circumferentially in a plane perpendicular to thelongitudinal axis of the channel and produced by the pressureof the air in the channel.5.7.1 Hoop Stress Calculation:S 5PD2t(1)where:S = hoop stress, psi,P = internal pressur
17、e,D = outside diameter of the channel, in., andt = normal wall thickness, in.6. Equipment6.1 Sealing Equipment, appropriate to seal the two ends ofthe air channel.6.2 A device is necessary to insert air into the open channeland allow monitoring its pressure. This device is unique to eachuser.6.3 Air
18、 Pump or Air Pressure Supply, capable of generatingup to 517 kPa (75 psi) pressure is necessary.6.4 Pressure Gauge, capable of indicating the air pressure in7 kPa (1 psi) increments within the test range.6.5 Any equipment used on the geomembrane must beplaced on an adequate cushion to preclude damag
19、e to thegeomembrane.6.6 Flexible Hose, used to connect the air supply to the airpressure device.6.7 Knife or Scissors, capable of cutting or trimming theliner material.6.8 Infrared or Probe Type Thermometer, able to measurethe sheet temperature to an accuracy of 6 1.1C (6 2F).NOTE 1All gauges should
20、 be calibrated as specified by the manufac-turer, or at a frequency of at least once per year.NOTE 2A change of 1 degree Fahrenheit equals a change of59 = 0.56degrees Celsius.7. Procedure7.1 After the dual track seam is fabricated and the length ofseam that is to be evaluated is determined, seal one
21、 end of thecontinuous air channel with a clamp.7.2 Connect the pressure gauge and air insertion tool di-rectly into the air channel.7.3 Connect an air supply to the pressure gauge and inser-tion tool and pressurize the air channel to the pressureappropriate for the PVC geomembrane sheet temperature.
22、(Refer to Table 1.)7.4 Maintain the minimum pressure from the source for aminimum of 30 seconds.7.5 Inspect the seam from the clamped end for completeinflation. If the seam completely inflates and there is no audibleor visible evidence of air leakage, the seam passes the test.7.6 If the channel will
23、 not pressurize there is a leak in theseam, provided air is not leaking at the clamp or air supply tool.7.7 Inspect the seam from the clamped end and locate theleak area. Because of the flexibility and elongation factors of aPVC geomembrane a leak can be detected by sound. Anothertechnique to locate
24、 a leak is to have an additional clamp and atten foot increments clamp off the channel to locate the air leak.Because of the flexibility of PVC geomembrane, a wrinkle canbe made in the seam area and folded over on itself andclamped.7.8 At completion of the test open the air channel at the endopposit
25、e the pressure gauge. Air should rush out and thepressure gauge should register an immediate drop in pressure,indicating that the entire length of the seam has been tested. Ifnot there is a blockage in the seam.7.9 Mark both ends of the seam with the inspectors initials,seam identification letter an
26、d/or numbers, length inspected,date, sheet temperature and test pressure.7.10 Any dual seam that cannot be successfully tested usingthis specification should be marked and tested using anothernondestructive testing practice.NOTE 3Leaks around the end seals and air pressure device canusually be locat
27、ed by putting moisture around the suspected area andlooking for air bubbles.8. Corrective Action8.1 Air Channel BlockageCamp at the blockage and testboth directions. Due to the flexibility of PVC Geomembranes,Inflation of the air channel up to the blockage is very visible.TABLE 1 Pressure Required t
28、o Verify 15 lb/in. Seam PeelStrength for PVCSheetTemperatureCSheetTemperatureFAirPressureKPaAirPressurePSIHold Time4.5 40 414 60 30 seconds7 45 386 56 30 seconds10 50 358 52 30 seconds13 55 324 47 30 seconds15.5 60 290 42 30 seconds18 65 276 40 30 seconds21 70 248 36 30 seconds24 75 234 34 30 second
29、s26.5 80 200 29 30 seconds29.5 85 186 27 30 seconds32 90 172 25 30 seconds35 95 165 24 30 seconds37.5 100 152 22 30 seconds40.5 105 138 20 30 seconds43.5 110 131 19 30 secondsNOTEData for this chart is acquired from research papers in Section 2and the bibliography.D7177052Therefore releasing the air
30、 pressure at the testing devise isacceptable in this situation.8.2 SeamWhen a seam failure is detected the seam shouldbe retested on both sides of the failure if the two parts pass thenrepair the area. If the seam failures continue the onsite CQAand installer shall discuss and agree on corrective ac
31、tion torepair or to rebuild the seam.NOTE 4This test purposes to measure the strength and continuity ofthe seam. If repeated failures occur the seam shall be rebuilt.9. Report9.1 The report should include the seam identification letterand/or numbers, date and time of inspection, inspectorsidentifica
32、tion, length of seam tested; sheet temperature, testpressure and pass fail results. If fail, corrective action should bedescribed in detail.10. Keywords10.1 air channel; canal; destructive test; dual track; flexiblesheeting; geomembrane; landfill; non-destructive test; poly(vi-nyl chloride); polyvin
33、yl chloride resin; pond liner; PVC;reservoir; water containment membrane; water leakage resis-tanceBIBLIOGRAPHY(1) Thomas, R. W. and Stark, T. D., “Air Channel Testing of ThermallyBonded PVC Seams,” September 4, 2002(2) Thomas, R. W., Stark, T. D., and Choi, H., “Air Channel Testing ofThermally Bond
34、ed PVC Seams,” Geosynthetics International Jour-nal, Industrial Fabrics Association International (IFAI), Vol 10, No.3, October 2003, pp. 645-659.(3) Thomas, R. W. and Stark, T. D., “Air-Channel Testing of ThermallyBonded PVC Geomembrane Seams,” Geotechnical Fabrics Report,Industrial Fabrics Associa
35、tion International, Vol 20, No. 8, October2003, p. 10.(4) Stark, T. D., Choi, H., and Thomas, R. W., “Low Temperature AirChannel Testing of Thermally Bonded PVC Seams,” InternationalAssociation of Geosynthetic Installers, Industrial Fabrics Associa-tion International (IFAI), Vol 4, Issue 1, Winter 2
36、004, pp. 5-7.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of suc
37、h rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee 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 addit
38、ional standardsand should 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
39、 ASTM Committee on Standards, 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 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D7177053
