ASTM_D_7966_-_D_7966M_-_16.pdf

Designation:D7966/D7966M16Standard Test Method forResistance to Creep of Adhesives in Static Shear byCompression Loading(Wood-to-Wood)1This standard is issued under the fixed designation D7966/D7966M;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.1.Scope1.1 This test method covers the determination of creepproperties of structural adhesives in wood-to-wood bondswhen a standardized specimen is subjected to shearing stressesat various levels of static load,constant temperature,andrelative humidity.Apparatus and procedures are provided forshear deformation(creep)of adhesive bonds under static load.This test method is used under the indicated conditions toevaluate resistance to creep properties of a structural woodadhesive.1.2 The test method is used to evaluate creep performanceof adhesives suitable for the bonding of wood,includingtreated wood,into structural wood products for generalconstruction,marine use,or for other uses where a high-strength general construction,creep-resistant,durable adhesivebond is required.Individual block shear specimens are pre-pared from adhesively bonded laminations,subjected to aconstant load under various combinations of temperature andrelative humidity,and the amount of creep measured.1.3 Creep of structural wood adhesives as measured by thistest method may not be comparative to other ASTM methodsand is limited to the conditions of the test and procedurescontained herein.1.4 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.1.5 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:2D905 Test Method for Strength Properties of AdhesiveBonds in Shear by Compression LoadingD907 Terminology of AdhesivesD1101 Test Methods for Integrity of Adhesive Joints inStructural Laminated Wood Products for Exterior UseD2395 Test Methods for Density and Specific Gravity(Rela-tive Density)of Wood and Wood-Based MaterialsD2559 Specification for Adhesives for Bonded StructuralWood Products for Use Under Exterior Exposure Condi-tionsD4442 Test Methods for Direct Moisture Content Measure-ment of Wood and Wood-Based MaterialsE4 Practices for Force Verification of Testing Machines2.2 Other Document:3CSA O112.9 Evaluation of Adhesives for Structural WoodProducts(Exterior Exposure)2.3 ASTM Adjuncts:Compression-Shear Creep Test Apparatus43.Terminology3.1 Definitions:Many terms in this test method are definedin Terminology D907.3.1.1 laminated wood,nthe fabricated product resultingfrom the bonding of two or more laminations,with eachlamination made from one or more pieces bonded eitherlengthwise,edgewise,or both,and all with the direction of thegrain essentially parallel,to form a larger piece such as astructural member.3.1.1.1 DiscussionLaminated wood as defined in D1101.3.1.2 stress,nthe force exerted per unit area at a pointwithin a plane.3.2 Definitions of Terms Specific to This Standard:1This test method is under the jurisdiction of ASTM Committee D14 onAdhesives and is the direct responsibility of Subcommittee D14.30 on WoodAdhesives.Current edition approved May 1,2016.Published June 2016.Originallyapproved in 2014.Last previous edition approved in 2014 as D7966/D7966M 14.DOI:10.1520/D7966_D7966-16.2For 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 APA The Engineered Wood Association,7011 S.19th St.,Tacoma,WA 98466-5333,www.apawood.org.4Available from ASTM International Headquarters.Order Adjunct No.ADJ-ADJD4680.Original adjunct produced in 1987.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2.1 average creep of specimen,ncalculated creep dis-placement in the bondline of a specimen as shown in Fig.1(D1+D2)/2.3.2.2 maximum average creep,nthe largest average creepobserved with any one test specimen from a test assembly.3.2.3 overall average creep,nthe average creep observedin the test assembly based on the average creep of the testedspecimens.3.2.4 laminated test assembly,nan assembly formed bybonding layers of lumber with an adhesive so that the grain ofall laminations is essentially paralle