1、Designation: D 905 03Standard Test Method forStrength Properties of Adhesive Bonds in Shear byCompression Loading1This standard is issued under the fixed designation D 905; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year o
2、f last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.INTRODUCTIONThe accuracy of the results of str
3、ength 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
4、 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 gluing.(2) Complete mixing directions for the adhesive.(3) Condition
5、s 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 ro
6、om 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 glu
7、e 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
8、 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. Scope*1.1 This test method covers the determination of the com-parative
9、shear strengths of adhesive bonds used for bondingwood and other similar materials, when tested on a standardspecimen under specified conditions of preparation, condition-ing, and loading in compression. This test method is intendedprimarily as an evaluation of adhesives for wood.1.2 The values stat
10、ed in SI units are to be regarded as thestandard. The values given in parentheses 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 appr
11、o-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.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 Oct. 1, 2003. P
12、ublished October 2003. Originallyapproved in 1947. Last previous edition approved in 1998 as D 905 98.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.2. Referenced Doc
13、uments2.1 ASTM Standards:2D 143 Test Methods for Small Clear Specimens of TimberD 907 Terminology of Adhesives3. Terminology3.1 DefinitionsMany terms in this test method are definedin Terminology D 907.4. Significance and Use4.1 It cannot be assumed that this test method measures thetrue shear stren
14、gth 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, whe
15、n 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 D 143, these effectsare self correcting so that the measur
16、ed 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 rheological properties.
17、Themore viscoelastic or plastic the adhesive, the greater effect.Thermosetting adhesives like urea- and phenol-formaldehydeare elastic. Their bond strengths can be measured over a rangeof loading rate from 0.038 to 1.27 cm/min (0.015 to 0.5in./min) with no apparent affect. Thermoplastic adhesives li
18、kepolyvinyl acetate, hot melts, and elastomer-based adhesivesexhibit a broad range of elastic, viscoelastic, and plasticbehaviors. Their bond strengths will be affected to varyingdegrees by changing the loading rate. Generally, increasing therate, increases the measured strength.4.2 This test method
19、 is suitable for product research anddevelopment, qualifying adhesives in accordance with certainproduct or performance specifications, and monitoring bondingprocess control. This test method may be suitable for compar-ing and selecting adhesives, however, such comparisons mustbe made with caution s
20、ince the measured strength of someadhesives may be different in different types of joints. Strengthvalues obtained by this test method are not suitable as designshear strengths values without adjustment by certain engineer-ing design factors.5. Apparatus5.1 The testing machine shall have a capacity
21、of not lessthan 6810 kg (15 000 lb) in compression and shall be fittedwith a shearing tool containing a self-aligning seat to ensureuniform lateral distribution of the load. The machine shall becapable of maintaining a uniform rate of loading such that theload may be applied with a continuous motion
22、 of the movablehead to maximum load at a rate of 5 mm (0.20 in.)/min with apermissible variation of 625 %. The shearing tool shown inFig. 1 has been found satisfactory. The testing machine shall belocated in an atmosphere such that the moisture content of thespecimens developed under the conditions
23、prescribed in Sec-tion 8 is not noticeably altered during testing.6. Test Specimens6.1 Test specimens shall conform to the form and dimen-sions shown in Fig. 2. The specimens shall be cut from testjoints prepared as described in Sections 7 and 8.6.2 At least 20 specimens shall be tested, representin
24、g atleast four different joints.7. Preparation of Test Joints7.1 Hard maple blocks (Acer saccharum or Acer nigrum),having a minimum sp gr of 0.65 based on oven-dry weight and2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For
25、Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.FIG. 1 Shearing ToolD905032volume shall be selected (see Note). These blocks shall be ofstraight grain and free from defects including knots, birdseye,short grain, decay, and any unusual
26、discolorations within theshearing area. The blocks shall be of suitable size preferably sothat five test specimens may be cut from one test joint as shownin Fig. 3. Blocks approximately 19 by 63.5 by 304 mm (34 by212 by 12 in.) have been found to be satisfactory for thispurpose. The grain direction
27、shall be parallel to the longestdimension of the block. The blocks shall be at the equilibriummoisture content recommended by the manufacturer of theadhesive. In the absence of such recommendation, the moisturecontent shall be from 10 to 12 % based on oven-dry weight asdetermined on representative s
28、amples in accordance with the“Moisture Determination” section of Test Methods D 143. Theblocks shall be surfaced, just prior to gluing, preferably with ahand-feed jointer, and the blocks weighed and assembled inpairs so that blocks of approximately the same specific gravityare glued together. The su
29、rfaces shall remain unsanded andshall be free from dirt.NOTE 1A method for selecting maple blocks of satisfactory specificgravity is described in the Appendix to this method. For referee tests, thespecific gravity of blocks may be determined in accordance with theprocedure described in the “Specific
30、 Gravity and Shrinkage in Volume”section of Test Methods D 143.7.2 The adhesive shall be prepared and applied to the blocksin accordance with the procedure recommended by the manu-facturer of the adhesive. The glue-coated blocks shall then beassembled and pressed, likewise in accordance with the rec
31、-ommendations of the manufacturer of the adhesive.8. Conditioning of Test Joints8.1 The joints, upon removal from pressure shall be condi-tioned at a relative humidity of 50 6 2 % and at a temperatureof 23 6 1C (73.4 6 2F) either for a period of 7 days or untilspecimens reach equilibrium as indicate
32、d by no progressivechanges in weight, whichever is the shorter period. The lengthof this period of conditioning may be extended beyond thislimit by written agreement between the purchaser and themanufacturer of the adhesive.9. Preparation of Specimens9.1 Cut the specimens as shown in Fig. 3 so that
33、the graindirection is parallel to the direction of loading during test. Takecare in preparing the test specimens to make the loadedsurfaces smooth and parallel to each other and perpendicular tothe height. Take care also in reducing the lengths of thelaminations to 44.4 mm (134 in.) to ensure that t
34、he saw cutsextend to, but not beyond, the glue line. Measure the width andlength of the specimen at the glue line to the nearest 0.25 mm(0.010 in.) to determine the shear area.9.2 Retain specimens in the conditioning atmosphere de-scribed in Section 8 until tested, except during the cuttingoperation
35、s.10. Procedure10.1 Place the test specimen in the shearing tool so that theload may be applied as described in Section 5. The position ofthe specimen in one type of shearing tool is shown in Fig. 1.Apply the loading with a continuous motion of the movablehead at a rate of 5 mm (0.20 in.)/min to fai
36、lure as prescribed inSection 5.11. Calculation11.1 Calculate the shear stress at failure in kilopascals(pounds-force per square inch) based on the bond line areabetween the two laminations measured to the nearest 0.06 cm2(0.01 in.2), and report for each specimen together with theestimated percentage
37、 of wood failure.12. Report12.1 The report shall include the following:12.1.1 Complete identification of the adhesive tested, in-cluding type, source, manufacturers code numbers, form, etc.12.1.2 Application and bonding conditions used in prepar-ing the specimens.12.1.3 Conditioning procedure used f
38、or the specimens.12.1.4 Temperature and relative humidity in the test room.12.1.5 Number of specimens tested.12.1.6 Number of joints represented.12.1.7 Maximum and minimum shear stresses at failure andpercentages of wood failure. The standard deviation or allindividual test values, or both, for the
39、failing load values andwood failure values may be included in the report at the optionof either the purchaser or the manufacturer of the adhesive.12.1.8 The average shear stress at failure and the averagepercentage of wood failure.Metric Equivalentsin.mm146.3341913444.4250.8FIG. 2 Form and Dimension
40、s of Test SpecimenMetric Equivalentsin.mm146.3341913444.4250.8FIG. 3 Test Joint Showing Method of Cutting Five TestSpecimensD90503313. Precision and Bias13.1 Precision:13.1.1 Precision has two components: repeatability at agiven test site and reproducibility between test sites. Theprecision of this
41、test method is affected by many factorsincluding, but not limited to: (1) the wood species, (2) theboards selected, (3) grain direction, (4) growth ring orientation,(5) the quality of the bonded joint, (6) the condition of theshear tool, (7) the precision on the testing machine, and (8) theoperator.
42、 When the specimen fails primarily in the wood, thenormally variability of the wood strength affects the precision.The coefficient of variation of shear strength parallel to thegrain is 14 % for a given species of wood.13.1.2 Repeatability at a Given Site:13.1.2.1 In a study in which all the above f
43、actors wereclosely controlled and the specimens were bonded with phenol-resorcinol formaldehyde adhesive, the coefficient of variationranged from 2.4 up to 13.0 %, with most values in the range of3to6%.13.1.2.2 In a study in which all the above factors, exceptboard and growth ring orientation, were
44、controlled, the coef-ficients of variation ranged from 8 to 11 % for casein bondedspecimens, 4 to 12 % for two polyvinyl acetates, 22 to 27 % foran elastomer-based, and 14 to 21 % for phenol-resorcinolformaldehyde adhesive bonded specimens.13.1.3 Reproducibility from site to site:13.1.3.1 The reprod
45、ucibility of this test method has not beenestablished.13.2 BiasBias is the difference between the true shearstrength of the adhesive bond and the strength measured by amethod that is repeatable. Bias arises from the design, method,rate of loading the specimen, and from the strength of thewood.14. Ke
46、ywords14.1 adhesive; bond; compression; compression loading;shear; strength propertiesAPPENDIX(Nonmandatory Information)X1. METHOD FOR SELECTING MAPLE BLOCKS OF SATISFACTORY SPECIFIC GRAVITYX1.1 Cut the hard maple blocks into some standard sizesuch as 19 by 63.5 by 304 mm (34 by 212 by 12 in.) after
47、conditioning. Measure the linear dimensions of the blocks ininches, using a suitable caliper or other measuring device.Determine the percentage moisture content of the blocks inaccordance with the “Moisture Determination” section of TestMethods D 143. Do not use these samples in further tests.X1.2 C
48、alculate the volume of the blocks to the nearest 1cm3(0.1 in.3) and express the average percentage moisturecontent to the nearest whole number. Determine the numericalvalue of the factor for this moisture content by reference toTable X1.1, which is based on hard maple blocks that have aspecific grav
49、ity of 0.65 on the oven-dry weight and volumebasis and which were conditioned to various moisture contentvalues.X1.3 Multiply the factor in Table X1.1 by the volume of theblock in cubic inches to obtain the weight of the block in gramswhich would have a specific gravity of 0.65 on the oven-dryweight and volume basis.D905034SUMMARY OF CHANGESCommittee D14.30 has identified the location of selected changes to this standard since the last issue(D 905 98) that may impact the use of this standard.(1) No sections were changed that might impact the use of thisstandard.A
