ASTM_D_4632_-_D_4632M_-_15a.pdf

Designation:D4632/D4632M15aStandard Test Method forGrab Breaking Load and Elongation of Geotextiles1This standard is issued under the fixed designation D4632/D4632M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This test method is an index test which provides aprocedure for determining the breaking load(grab strength)and elongation(grab elongation)of geotextiles using the grabmethod.This test method is not suitable for knitted fabrics andalternate test methods should be used.While useful for qualitycontrol and acceptance testing for a specific fabric structure,the results can only be used comparatively between fabricswith very similar structures,because each different fabricstructure performs in a unique and characteristic manner in thistest.The grab test methods does not provide all the informationneeded for all design applications and other test methodsshould be used.1.2 Procedures for measuring the breaking load and elon-gation by the grab method in both the dry and wet state areincluded;however,testing is normally done in the dry condi-tion unless specified otherwise in an agreement or specifica-tion.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.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:2D76/D76M Specification for Tensile Testing Machines forTextilesD123 Terminology Relating to TextilesD1776/D1776M Practice for Conditioning and Testing Tex-tilesD2905 Practice for Statements on Number of Specimens forTextiles(Withdrawn 2008)3D4354 Practice for Sampling of Geosynthetics and RolledErosion Control Products(RECPs)for TestingD4439 Terminology for GeosyntheticsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 Definitions:3.1.1 atmosphere for testing geotextiles,nair maintainedat a relative humidity of 65 6 5%relative humidity andtemperature of 21 6 2C 70 6 4F.3.1.2 breaking load,nthe maximum force applied to aspecimen in a tensile test carried to rupture.3.1.3 cross-machine direction,nthe direction in the planeof the fabric perpendicular to the direction of manufacture.3.1.4 elongation at break,nthe elongation correspondingto the breaking load,that is,the maximum load.3.1.5 geotextile,nany permeable textile material usedwith foundation,soil,rock,earth,or any other geotechnicalmaterial,as an integral part of a man-made product,structure,or system.3.1.6 grab test,nin fabric testing,a tension test in whichonly a part of the width of the specimen is gripped in theclamps.3.1.6.1 DiscussionFor example,if the specimen width is101.6 mm 4 in.and the width of the jaw faces 25.4mm 1 in.,the specimen is gripped centrally in the clamps.3.1.7 machine direction,nthe direction in the plane of thefabric parallel to the direction of manufacture.1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.01 on Mechani-cal Properties.Current edition approved May 15,2015.Published June 2015.Originallyapproved in 1991.Last previous edition approved in 2015 as D4632/D4632M15.DOI:10.1520/D4632_D4632M-15A.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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.8 For definitions of other terms used in this test method,refer to Terminology D123 or Terminology D4439.4.Summary of Test Method4.1 A continually increasing load is applied longitudinallyto the specimen and the test is carried to rupture.Values for thebreaking load and elongation of the test specimen are obtainedfrom machine scales or dials,autographic recording charts,orinterfaced computers.5.Significance and Use5.1 The grab method is applicable whenever it is desired todetermine the“effective strength”of the fabric in use,that is,