ASTM_D_5820_-_95_2011.pdf

Designation:D582095(Reapproved 2011)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,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 The practice covers a nondestructive evaluation of thecontinuity of parallel geomembrane seams separated by anunwelded air channel.The unwelded air channel between thetwo distinct seamed regions is sealed regions is sealed andinflated with air to a predetermined pressure.Long lengths ofseam can be evaluated by this practice more quickly than byother common nondestructive tests.1.2 This practice should not be used as a 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 for geomem-brane seams that include an air channel.Practice D4437 maycontinue to be used for other types of seams.The user isreferred to the referenced standards,or to EPA/530/SW-91/051for additional information regarding geomembrane seamingtechniques and construction quality assurance.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 limitations 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 GeosyntheticsD4491 Test Methods for Water Permeability of Geotextilesby Permittivity2.2 Other Standard:EPA/530/SW-91/051Technical Guidance Document:In-spection Techniques for the Fabrication of GeomembraneField Seams33.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 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 flows througha geosynthetic when tested in accordance with Test MethodsD4491.3.1.5 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 the two welded zones.Both ends of the airchannel are sealed and then a pressure gauge is attached to 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 of the pressure.4.4 Maximum allowable loss of air pressure varies depend-ing upon thickness,stiffness and type of material of thegeomembrane.1This 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 June 1,2011.Published July 2011.Originally approvedin 1995.Last previous edition approved in 2006 as D5820 95(2006).DOI:10.1520/D5820-95R11.2For 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 website.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 States1 5.Significance and Use5.1 The increased use of geomembranes as barrier materialsto restrict liquid or gas movement,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 and water tightness.The test isnot intended to provide any indication of the physical strengthof the seam.5.2 This practice recommends an air pressure test within thechannel created between dual seamed tracks whereby thepresenceofunbondedsectionsorchannels,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 from the appropriate poly-mers and compounding i