ASTM_D_3931_-_08_2015.pdf

Designation:D393108(Reapproved 2015)Standard Test Method forDetermining Strength of Gap-Filling Adhesive Bonds inShear by Compression Loading1This standard is issued under the fixed designation D3931;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 This test method covers the determination of compara-tive shear properties of gap-filling adhesives in wood-to-woodjoints at specified thicknesses of bondline in the dry condition,when tested on standard specimens under specified conditionsof preparation,conditioning,and loading in compression.Thistest method is intended as an evaluation of gap-filling adhe-sives such as those used to bond plywood to lumber,lumber tolumber,and other similar materials in building constructions.1.2 This test method also may be used to determine shearproperties of gap-filling adhesives in species of wood and inthicknesses of bondline other than those specified for thecomparative tests of shear properties within this test method.All procedures specified herein are applicable,excepting re-quirements for wood species and specific gravity,and thick-nesses of bondlines.1.3 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered 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:2D143 Test Methods for Small Clear Specimens of TimberD905 Test Method for Strength Properties of AdhesiveBonds in Shear by Compression LoadingD1151 Practice for Effect of Moisture and Temperature onAdhesive BondsE171 Practice for Conditioning and Testing Flexible BarrierPackaging3.Terminology3.1 Definitions:3.1.1 gap-filling adhesive,nan adhesive capable of form-ing and maintaining a bond between surfaces that are notclose-fitting.3.1.1.1 DiscussionClose-fitting is relative to a given ma-terial and industry;for example,standards in constructiondiffer from standards in electronics.Some adhesives will bondby bridging without completely filling the gap;others by fillingthe gap completely.4.Significance and Use4.1 Structural design based on strength-of-materials prin-ciples requires knowledge of the mechanical properties of thestructural components,including adhesives.By nature of theiruse,the most important property of adhesive is shear strength.4.2 Shear strength measured by this test method is suitablefor use in adhesive development,manufacturing qualitycontrol,and in materials performance specifications,as well asstructural design.5.Apparatus5.1 Testing Machine,having a capacity of about 15 000 lb(6818 kg)in compression or of sufficient capacity to test theadhesive in use.The machine shall be fitted with a shearingtool containing a self-aligning seat to ensure uniform lateraldistribution of the load.The machine shall be capable ofmaintaining a uniform rate of loading such that the load may beapplied with a continuous motion of the movable head tomaximum load at a rate of 9.20 in.(5.0 mm)/min with apermissible variation of 625%.The shearing tool shown inFig.1 of Test Method D905 has been found satisfactory.Locatethe testing machine in an atmosphere such that the moisturecontent of the specimens,developed under the conditionsprescribed in 7.3,is not noticeably altered during testing.1This test method is under the jurisdiction of ASTM Committee D14 onAdhesives and is the direct responsibility of Subcommittee D14.70 on ConstructionAdhesives.Current edition approved April 1,2015.Published April 2015.Originallyapproved in 1980.Last previous edition approved in 2008 as D3931 08.DOI:10.1520/D3931-08R15.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.Test Specimen and Sample6.1 Test specimens for adhesive bonds shall conform to theform and dimensions shown in Fig.1.Prepare bonded assem-blies as described in 7.1.Prepare test specimens for testing asdescribed in 7.2.6.2 Determine mean shear strengths of bonds at bondlinethicknesses of 0.006 and 0.060 in.(0.15 and 1.52 mm).Testsfor strengths of bonds at other thicknesses,in addition to thosespecified,shall be optional upon agreement between themanufacturer and the user.6.3 Test a minimum of 28 specimens,representin