1、Designation: D5266 13Standard Practice forEstimating the Percentage of Wood Failure in AdhesiveBonded Joints1This standard is issued under the fixed designation D5266; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t 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 practice provides procedures for estimating thepercentage of wood failure that occurs in plywood-shear,block-shear,
3、finger joint test specimens, or any other bondlineinvolving wood.1.2 The values stated in SI units are to be regarded as thestandard. The values in parentheses are provided for informa-tion only.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use.
4、 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 Compres
5、sion LoadingD906 Test Method for Strength Properties of Adhesives inPlywood Type Construction in Shear by Tension LoadingD2559 Specification for Adhesives for Bonded StructuralWood Products for Use Under Exterior Exposure Condi-tionsD4688 Test Method for Evaluating Structural Adhesives forFinger Joi
6、nting LumberD5572 Specification forAdhesives Used for Finger Joints inNonstructural Lumber ProductsD5751 Specification forAdhesives Used for Laminate Jointsin Nonstructural Lumber Products2.2 American National Standards:ANSI/HPVA HP-1-2009 American National Standard forHardwood and Decorative Plywoo
7、d3ANSI A190.1-2012 American National Standard for WoodProductsStructural Glued, Laminated Timber32.3 Other Documents:American Plywood Association Proposed Standard Methodfor Estimating Percentage Wood Failure on PlywoodShear Specimens4PS 1 U.S. Product Standard for Construction and IndustrialPlywood
8、4CSA O112.9 Evaluation of Adhesives for Structural WoodProducts (Exterior Exposure)4General Technical Report FPL-GTR-1905Inspection Bureau Memorandum No. 1 Interpretation ofWood Failure42.4 ASTM Adjunct:Photographs for Visually Estimating the Percentage of WoodFailure in Standard Adhesively Bonded S
9、pecimens63. Terminology3.1 Definitions:3.1.1 deep wood failure, nfailure that is invariably severalto many cells away from the adhesive layer, in which thefracture path is strongly influenced by the grain angle andgrowthring structure.3.1.2 shallow wood failure, nfailure that is invariablywithin the
10、 first one or two layers of cells beyond the adhesivelayer in which the fracture path is not influenced by thewoodgrain angle or growth-ring structure (see 7.7 and 8.1).1This practice is under the jurisdiction of ASTM Committee D14 on Adhesivesand is the direct responsibility of Subcommittee D14.30
11、on Wood Adhesives.Current edition approved May 1, 2013. Published July 2013. Originally approvedin 1992. Last previous edition approved in 2005 as D5266 99 (2005). DOI:10.1520/D5266-13.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceast
12、m.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Hardwood Plywood however, the practice shouldbe consistent. If the specimen is rotated to detect shallow woodfailure, always reposition the specimen in the stan
13、dard positionwhen making the estimate of wood failure.7.7 If there are scattered areas of shallow wood failure, blowor brush loose fibers from the surface. Count as wood failureonly areas with wood cells that actually adhere to the adhesive.Mentally group those areas into an area that can be estimat
14、ed.7.8 Do not count as wood failure isolated wood particlessuch as sawdust and slivers that were on the surface during thebonding process, unless these particles were actually torn apartduring testing.7.9 It is often helpful to use a ruler or a scribed transparenttemplate as described in 5.2 as an a
15、id to estimate the totalpercentage of wood failure, or the percentages of shallow anddeep wood failure.7.10 Mentally divide the surface into quadrants for estimat-ing the areas of various forms of failure. Estimate the woodfailure on both halves of the specimen, but do not count thewood failure from
16、 matching areas more than once.Alternatively, read the wood failure percentage on both halvesof the specimen and divide the sum by 2.7.11 Estimate shallow and deep or total wood fiber failure ofeach specimen to the nearest 5 %, with a maximum of 100 %of the total bonded test area.NOTE 2The North Ame
17、rican plywood industry recognizes shallowwood failure, but does not give it any less or any more significance thandeep wood failure. Therefore in the case of conformance to PS 1, shallowand deep wood failure are not distinguished and should be estimatedtogether.7.12 In the absence of any directives
18、within a referencedstandard, shallow and deep wood failure are not to be distin-guished and are to be estimated together.8. Evaluation of Wood Failure8.1 Accurate and consistent estimates are important.Generally, wood failure estimators do not have difficulty withvery high or low percentages of wood
19、 failure. Difficulty occursin the middle pass-fail range (30 to 85 %, depending on thestandard) where accuracy is most important. Special care mustbe taken in this range.NOTE 3Round robin studies of estimated wood failure indicate theamount of variation between individual readers on the same standar
20、d testspecimen can vary significantly depending upon the wood species andcolor of adhesive. Reader differences in the range of 15 to 40 % on anindividual specimen within the same middle pass-fail range were notfound to be uncommon. If this range of estimates between readers isapplied to a group of 2
21、0 specimens, the maximum expected differenceFIG. 2 Positioning of Test Specimen in Relation to Light Sourceand EyeD5266 133between readers on the same group of specimens would be 4 to 8 %respectively.88.2 The color of the adhesive and recognition of shallowwood failure, if present, affect the estima
22、te. Shallow woodfailure is more easily recognized and distinguished with a darkadhesive as a background. When the adhesive is light colored,shallow wood failure can be easily mistaken for adhesive oradhesion failure.8.3 If the percentage of wood failure is high and the failureis mostly on one side o
23、f the adhesive layer, the grain orienta-tion may be a factor. In this case, the grain orientation shouldbe determined and recorded.8.4 Record any indications of poor spread, lack of adhesivetransfer, or other bonding problems.9. Report9.1 Report for each specimen as follows:9.1.1 The exposure or tre
24、atment of the specimen beforetesting.9.1.2 The percentage of total wood failure.9.1.3 If there is shallow wood failure, report separatepercentages for shallow and deep wood failure.9.1.4 Grain deviations, if affecting the percentage of woodfailure.9.1.5 Indications of improper bonding conditions aff
25、ectingthe percentage of wood failure.9.2 For all specimens, report the following:9.2.1 The average of each wood failure category; total,shallow, deep.9.2.2 The standard deviation of each category of woodfailure percentage.10. Keywords10.1 adhesives; finger joints; parallel laminates; plywood;wood fa
26、iluresAPPENDIX(Nonmandatory Information)X1. ASTM D5266 ADJUNCT8CSAA370/SubCommittee 05, Standard O112.9410, Evaluation of Adhesivesfor Structural Wood Products (exterior exposure): C4.7.2 Precision Statement ofEstimating Percent Wood Failure.D5266 134FIG. X1.1 Visually Estimating the Percentage of W
27、ood Failure in Standard Adhesively Bonded Specimens(Left) Three-ply, Douglas-fir, Phenol-formaldehyde adhesive.(Right) Three-ply, Yellow-birch, Urea-formaldehyde adhesive.D5266 135FIG. X1.2 Visually Estimating the Percentage of Wood Failure in Standard Adhesively Bonded Specimens(Left) Three-ply, So
28、uthern pine, Phenol-formaldehyde adhesive.(Right) Two-ply, Yellow-birch, Urea-formaldehyde adhesive.D5266 136FIG. X1.3 Visually Estimating the Percentage of Wood Failure in Standard Adhesively Bonded Specimens(Top left) Ponderosa pine, light adhesive.(Top right) Ponderosa pine, dark adhesive.(Bottom
29、 left) Southern pine, light adhesive.(Bottom right) Southern pine, dark adhesive.D5266 137ASTM 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
30、of the validity of any such patent rights, 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
31、. Your comments are invited either for 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 com
32、ments have not received a fair hearing 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
33、 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).FIG. X1.4 Visually Estimating the Percentage of Wood Failure in Standard Adhesively Bonded Specimens(Above) Douglas-fir, dark adhesive.(Above right) Southern pine, dark adhesive.(Bottom right) Southern pine, dark adhesive.D5266 138
