ASTM_D_905_-_08_2013.pdf

Designation:D90508(Reapproved 2013)Standard Test Method forStrength Properties of Adhesive Bonds in Shear byCompression Loading1This standard is issued under the fixed designation D905;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.This standard has been approved for use by agencies of the U.S.Department of Defense.INTRODUCTIONThe accuracy of the results of strength tests of adhesive bonds will depend on the conditions underwhich the bonding process is carried out.Unless otherwise agreed upon by the manufacturer and thepurchaser,the bonding conditions shall be prescribed by the manufacturer of the adhesive.In order toensure that complete information is available to the individual conducting the tests,the manufacturerof the adhesive shall furnish numerical values and other specific information for each of the followingvariables:(1)The moisture content of the wood at the time of bonding.(2)Complete mixing directions for the adhesive.(3)Conditions for applications of the adhesive including the rate of spread or thickness of film,number of coats to be applied,whether to be applied to one or both surfaces,and the conditions ofdrying where more than one coat is required.(4)Assembly conditions before application of pressure,including the room temperature,length oftime,and whether open or closed assembly is to be used.(5)Curing conditions,including the amount of pressure to be applied,the length of time underpressure and the temperature of assembly when under pressure.It should be stated whether thistemperature is that of the bond line,or of the atmosphere at which the assembly is to be maintained.(6)Conditioning procedure before testing,unless a standard procedure is specified,including thelength of time,temperature,and relative humidity.Arange may be prescribed for any variable by the manufacturer of the adhesive if it can be assumedby the test operator that any arbitrarily chosen value within such a range or any combination of suchvalues for several variables will be acceptable to both the manufacturer and the purchaser of theadhesive.1.Scope1.1 This test method covers the determination of the com-parative shear strengths of adhesive bonds used for bondingwood and other similar materials,when tested on a standardspecimenunderspecifiedconditionsofpreparation,conditioning,and loading in compression.This test method isintended primarily as an evaluation of adhesives for wood.1.2 The values stated in SI units are to be regarded as thestandard.The values given in brackets are provided forinformation purposes only.1.3 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 TimberD907 Terminology of Adhesives1This 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 Oct.1,2013.Published October 2013.Originallyapproved in 1947.Last previous edition approved in 2008 as D905 081.DOI:10.1520/D0905-08R13.2For 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 D5266 Practice for Estimating the Percentage of WoodFailure in Adhesive Bonded Joints3.Terminology3.1 DefinitionsMany terms in this test method are definedin Terminology D907.4.Significance and Use4.1 It cannot be assumed that this test method measures thetrue shear strength of the adhesive bond.Many factors interfereor bias the measurement including the strength of the wood,thespecimen,the shear tool designs themselves,and the rate ofloading.4.1.1 Wood failure is very common in joints made withstrong adhesives.Although high wood failure is normallydesired,when it occurs the measured strength is lower than thetrue adhesive bond strength.4.1.2 Stress concentrations at the notches of the specimentend to lower the measured strength.In a similar test for theshear strength of solid wood,Test Methods D143,these effectsare self correcting so that the measured strength is close to thetrue shear strength of the wood.By analogy the same may betrue in this test method,however,other factors are alsoinvolved and may alter the relationship.4.1.3 The rate of loading affects the strength of an adhesivebond according to the adhesives rheologi