1、Designation: D 2339 98 (Reapproved 2004)Standard Test Method forStrength Properties of Adhesives in Two-Ply WoodConstruction in Shear by Tension Loading1This standard is issued under the fixed designation D 2339; the number immediately following the designation indicates the year oforiginal adoption
2、 or, in the case of revision, the year of 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.INTRODUCTIONThe accuracy of the results of strength tests of adhesive bonds depends on
3、the conditions underwhich the bonding process is carried out. Unless otherwise agreed upon between the manufacturer andthe purchaser, the bonding conditions shall be prescribed by the manufacturer of the adhesive. In orderto ensure that complete information is available to the individual conducting
4、the tests, themanufacturer of the adhesive shall furnish numerical values and other specific information for each ofthe following variables:(1) The moisture content of the wood at the time of bonding.(2) Complete mixing directions for the adhesive.(3) Conditions for application of the adhesive inclu
5、ding 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 whethe
6、r 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 the assembly when under pressure. It should be stated whether thistemperature is that of the bondline, or of the atmosphere at which
7、 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.A range may be prescribed for any variable by the manufacturer of the adhesive if it can be assumedby the test operat
8、or 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 adhesives when tes
9、ted on a standardspecimen and under specified conditions of preparation, con-ditioning, and testing. This test method is intended to beapplied only to adhesives used in bonding wood to wood.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for i
10、nformationonly.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.
11、2. Referenced Documents2.1 ASTM Standards:2D 143 Test Methods for Small Clear Specimens of TimberD 907 Terminology of Adhesives3. Terminology3.1 Definitions:3.1.1 shear, nin an adhesively bonded joint, stress, strain,or failure resulting from applied forces that tends to causeadjacent planes of a bo
12、dy to slide parallel in opposite direc-tions.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 April 1, 2004. Published April 2004. Originallyapproved in 1965. Last previous
13、edition approved in 1998 as D 2339 98.2For 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.1Copyright ASTM Interna
14、tional, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Significance and Use4.1 By the nature of the way adhesives are used in two-plywood construction, shear strength is an important performancecriteria.4.2 Shear strength measured by this test method is suitab
15、lefor use in adhesive development, manufacturing quality con-trol, and in materials-performance specifications.5. Apparatus5.1 Adjust the loading rate of the testing machine between4535 and 7560 g/s (600 and 1000 lb/min). Where the testingmachine is adjusted by rate of crosshead movement rather than
16、load application rate, select an appropriate head movement rateso as to yield an average load application rate in the 4535 and7560 g/s (600 and 1000 lb/min) range. Provide suitable gripsand jaws so that the specimen can be gripped tightly and heldin alignment as the load is applied. The grips and ja
17、ws shownin Fig. 1 have been found satisfactory. Locate the testingmachine in an atmosphere such that the moisture content of thespecimens developed under the conditions prescribed in Sec-tion 7 is not noticeably altered during testing.6. Preparation of Test Panels6.1 The standard substrate for this
18、test is 1.6 mm (116 in.)thick rotary-cut or sliced veneer of sweet birch (Betula lenta)or yellow birch (Betula alleghaniensis). Any other thickness orspecies of veneer may be substituted upon written agreementbetween the party requesting this test and the manufacturer ofthe adhesive. Select veneer t
19、hat is free of defects such as knotsor distorted grain around knots, cracks, short grain (fibers outof plane), rough surfaces, or unusual discoloration whichwould indicate decay. Do not sand the veneer.6.2 Cut the selected veneer into a size suitable for pressingand for cutting specimens with minima
20、l waste. Allow at least13 mm (12 in.) for trim around the edges.NOTE 1When cutting the veneer to size, ensure that the fiber directionis parallel and perpendicular to the edges. Appearance may be deceptive.If there is any question, check the fiber direction with a scratch awl.6.3 Condition the venee
21、r to within 61 % of the moisturecontent recommended by the adhesive manufacturer or theparty requesting this test. In the absence of any guideline,condition the veneer to 10 to 12 % moisture content based onthe oven dry weight. Check moisture content of recommendedsamples in accordance with Sections
22、 124 to 127 of TestMethods D 143.6.4 Prepare the adhesive in accordance with the adhesivemanufacturers instructions.NOTE 2If a species of lower strength is used and the specimens failpredominantly in tension at the saw kerfs, prepare and test a new set ofspecimens, either by using thicker veneers or
23、 by reducing the distancebetween the saw kerfs to 12.7 m (0.5 in.) (see Fig. 2).6.5 Apply the adhesive to each veneer in accordance withthe adhesive manufacturers instructions. Allow the prescribedopen assembly time, if any, before reassembling the pieces.6.6 Assemble the veneer into two-ply panels
24、so that thegrain in the two plies is parallel. Allow the prescribed closedassembly time, if any, before pressing. Press the assemblyunder the conditions prescribed by the adhesive manufacturer.7. Conditioning of Test Panels7.1 Upon removal from pressure, condition the panels at arelative humidity of
25、 50 6 2 % and at a temperature of 23 61C (73.4 6 2F) either for a period of 7 days or untilspecimens reach equilibrium as indicated by no progressivechange in weight, whichever is the longer period. The length ofthis period of conditioning may be extended beyond this limitby written agreement betwee
26、n the purchaser and the manufac-turer of the adhesive.8. Test Specimens8.1 Cut test specimens from the test panel as shown in Fig.3. Exercise care in grooving the specimens to ensure that thesaw cut extends to, but not beyond, the bondline. This can beaccomplished by first cutting the individual tes
27、t slips from thepanels as shown in Fig. 2 and then grooving them individuallyto the proper width, depth, and location with a hollow-groundgrooving saw or any other tool that will give equally satisfac-tory results. Alternatively, the panels can first be grooved to theproper width, depth, and locatio
28、n after which the individual testspecimens can be cut from them. Measure the width of eachspecimen and the distance between grooves to the nearest 0.25mm (0.010 in.) to determine the shear area.8.2 Retain the specimens in the conditioning atmospheredescribed in Section 7 until tested, except during
29、the cuttingoperations.8.3 Select and test at least 30 specimens, representing atleast three different panels.FIG. 1 Grips and Jaws FIG. 2 Size of Test Panel and Method of Cutting Test SpecimensD 2339 98 (2004)29. Procedure9.1 Place the test specimen in the jaws of the grips in thetesting machine and
30、 grip tightly so that the specimen isperfectly aligned and parallel to the centerline of the jaws. Ifjaws such as those in Fig. 1 are used, then the specimen shouldbe perfectly aligned with the pairs of jaws directly above eachother and in such a position that an imaginary straight verticalline woul
31、d pass through the glue line and through the points ofsuspension A and B as shown in Fig. 1. Place specimens in thejaws alternately so that in one case the upper notch is to the leftand in the next case toward the right. Apply the load at a rateof 4535 to 7560 g/s (600 to 1000 lb/min), or select a c
32、rossheadspeed that will yield this.10. Calculation10.1 Record the load at failure in kilograms (pounds), andcalculate the shear stress at failure as Newtons per square meter(pounds per square inch), based on shear area calculated to thenearest 0.06 mm2(0.01 in2). Estimate the percentage of woodfailu
33、re to the nearest 5 % for each test specimen.11. Report11.1 Report the following information:11.1.1 Complete identification of the adhesive tested, in-cluding type, source, manufacturer, code numbers, form, etc.,and reporting of the wood species used as well as its moisturecontent when used.11.1.2 A
34、pplication and bonding conditions used in prepar-ing the specimens,11.1.3 Species and dimensions of specimens if other thanprescribed in 6.1,11.1.4 Conditioning procedure used for the specimens,11.1.5 Temperature and relative humidity in the test room,11.1.6 Number of specimens tested,11.1.7 Number
35、of panels represented,11.1.8 Maximum and minimum loads at failure and percent-ages of wood failure. The standard deviation or all individualtest values, or both, for the failing load values and wood failurevalues may be included in the report at the option of either thepurchaser or the manufacturer
36、of the adhesive, and11.1.9 Average load at failure and the average percentage ofwood failure.12. Precision and Bias12.1 A precision and bias statement does not exist for thistest method because resources necessary for roundrobintesting have not been forthcoming.13. Keywords13.1 adhesive; shear stren
37、gth; tension loading; test method;wood; wood failureASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rig
38、hts, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for
39、 revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing
40、 you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).FIG. 3 Form and Dimensions of Test SpecimenD 2339 98 (2004)3
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