1、Designation: D 5055 08Standard Specification forEstablishing and Monitoring Structural Capacities ofPrefabricated Wood I-Joists1This standard is issued under the fixed designation D 5055; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revis
2、ion, 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.1. Scope1.1 This specification gives procedures for establishing,monitoring, and reevaluating structural capacit
3、ies of prefabri-cated wood I-joists. Capacities considered are shear, moment,and stiffness. Procedures for establishing common details aregiven and certain design considerations specific to woodI-joists are itemized.1.2 Contents of the StandardAn index and brief descrip-tion of the main features of
4、this specification are given inX1.1.1.1.3 Development of the StandardThe development andintent of this specification is discussed in Appendix X1.1.4 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are p
5、rovided for information onlyand are not considered 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-b
6、ility of regulatory limitations prior to use. A specific precau-tionary statement is given in 6.1.1.5.2. Referenced Documents2.1 ASTM Standards:2D 198 Test Methods of Static Tests of Lumber in StructuralSizesD 245 Practice for Establishing Structural Grades and Re-lated Allowable Properties for Visu
7、ally Graded LumberD 1990 Practice for Establishing Allowable Properties forVisually-Graded Dimension Lumber from In-Grade Testsof Full-Size SpecimensD 2559 Specification for Adhesives for Structural Lami-nated Wood Products for Use Under Exterior (Wet Use)Exposure ConditionsD 2915 Practice for Evalu
8、ating Allowable Properties forGrades of Structural LumberD 4761 Test Methods for Mechanical Properties of Lumberand Wood-Base Structural MaterialD 5456 Specification for Evaluation of Structural Compos-ite Lumber ProductsD 5457 Specification for Computing Reference Resistanceof Wood-Based Materials
9、and Structural Connections forLoad and Resistance Factor DesignD 7247 Test Method for Evaluating the Shear Strength ofAdhesive Bonds in Laminated Wood Products at ElevatedTemperaturesE4 Practices for Force Verification of Testing MachinesE 529 Guide for Conducting Flexural Tests on Beams andGirders
10、for Building ConstructionE 699 Standard Practice for Evaluation of Agencies In-volved in Testing, Quality Assurance, and Evaluating ofBuilding ComponentsIEEE/ASTM SI 10 Standard for Use of the InternationalSystem of Units (SI): The Modern Metric System2.2 U.S. Product Standards:3PS-1 Structural Plyw
11、oodPS-2 Performance Standard for Wood-Based Structural-Use Panels2.3 Other Standards:CSA O86 Engineering Design in Wood4CSA O112.7 Resorcinol and Phenol-Resorcinal Resin Ad-hesives4CSA O112.9 Evaluation of Adhesives for Structural WoodProducts (Exterior Exposure)4CSA O151 Canadian Softwood Plywood4C
12、SA O325 Construction Sheathing41This specification is under the jurisdiction of ASTM Committee D07 on Woodand is the direct responsibility of Subcommittee D07.02 on Lumber and EngineeredWood Products.Current edition approved April 1, 2008. Published May 2008. Originallyapproved in 1990. Last previou
13、s edition approved in 2007 as D 5055 07.2For 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 APATh
14、e Engineered Wood Association, 7011 South 19thStreet, Tacoma, WA98466, http:/www.apawood.org; and TECO, 2902 Terra Court,Sun Prairie, WI 53590, http:/.4Available from Canadian Standards Association (CSA), 5060 Spectrum Way,Mississauga, ON L4W 5N6, Canada, http:/www.csa.ca.1Copyright ASTM Internation
15、al, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Lumber Grading Rules Approved by American LumberStandards Committee (ALSC) or Canadian Lumber Stan-dards Accreditation Board (CLSAB)5SPS-4 Special Products Standard for Fingerjointed FlangeStock Lumber, 200163. T
16、erminology3.1 Definition:3.1.1 prefabricated wood I-joista structural membermanufactured using sawn or structural composite lumberflanges and structural panel webs, bonded together with exte-rior exposure adhesives, forming an “I” cross-sectional shape.These members are primarily used as joists in f
17、loor and roofconstruction.3.2 Definitions of Terms Specific to This Standard:3.2.1 capacity (or structural capacity)the numeric resultof certain calculations specified in this specification.3.2.2 design valuethe numeric value claimed by themanufacturer as appropriate for use in structural analysis.N
18、OTE 1A brief discussion of this issue is found in X1.9.3.2.3 structural composite lumbera composite of woodelements (for example, wood strands, strips, veneer sheets, ora combination thereof), bonded with an exterior grade adhesiveand intended for structural use in dry service conditions.4. Design C
19、onsiderations4.1 Design Value Adjustments:4.1.1 Duration of LoadPrefabricated wood I-joists shallbe designed using the strength adjustment for load durationused in sawn lumber. This adjustment is determined in accor-dance with the section on Duration of Load Under Modifica-tion of Allowable Properti
20、es for Design Use in Practice D 245.4.1.2 Repetitive MembersThe repetitive member factorfor prefabricated I-joists shall be taken as 1.0.NOTE 2Committee D07 chose to reduce the repetitive member factorto unity primarily for purposes of design simplicity. A discussion of thisdecision is given in Appe
21、ndix X1.4.1.3 TreatmentsSome pressure treatments affect materialstrength and the quality of prefabricated wood I-joists. TreatedI-joists shall not be used without evaluation of such effects.4.1.4 EnvironmentThe capacities developed in this speci-fication are applicable to joists used under dry condi
22、tions suchas in most covered structures.Appropriate adjustments for usesin other environments shall be made.4.2 Shear Design:4.2.1 Neglecting loads within a distance from the supportequal to the depth of the member shall not be permitted.4.2.2 Adjustments to the shear design value near the supportor
23、 at locations of continuity or where reinforcements areprovided must be substantiated by independent testing to thegeneral intended criteria for shear capacity herein.5. Materials5.1 Flange Stock:5.1.1 All flange material shall conform to the requirementsof 6.3. In addition, when the flange material
24、 is structuralcomposite lumber, the following properties shall be determinedin accordance with Specification D 5456: modulus of elasticity(flat or edge, depending on flange orientation in the I-joist),compression (parallel and perpendicular to grain), and naildesign values.5.1.2 End joints in purcha
25、sed flange stock are permittedprovided such joints conform to the general intent and Section10 of this specification.5.2 Web MaterialPanels shall conform to manufacturingor performance standards recognized by the applicable govern-ing code. Examples are PS-1 (or CSA O151) and PS-2 (orCSA O325). In a
26、ddition, all panels shall meet the equivalent ofExposure I requirements as specified in PS-1 or PS-2.5.3 AdhesivesAdhesives used to bond together compo-nents of the finished product shall conform to the requirementsin Specification D 2559 (or in Canada to Clause 13 ofCSA O86) for use under exterior
27、(wet-use) exposure condi-tions. In addition, adhesives used for web-to-web, web-to-flange, and flange-to-flange joints shall be qualified for heatdurability performance in accordance with 5.3.3. Appendix X3gives additional information and standards that shall be con-sidered when qualifying adhesives
28、 and adhesive-bonded mate-rials.NOTE 3Heat durable performance implies that a bonded joint willexhibit similar material resistance to solid wood in an elevated tempera-ture environment where the wood material surrounding the joint does notprovide thermal protection.5.3.1 Adhesives and binder systems
29、 used in the fabricationof Structural Composite Lumber products shall be evaluated inaccordance with Specification D 5456.5.3.2 Adhesives and binder systems used in the fabricationof panel products used as a web shall be evaluated inaccordance with PS-2 (or in Canada CSA O325) with theExposure 1 cla
30、ssification.5.3.3 AdhesivesHeat durability:5.3.3.1 Adhesives used for web-to-web, web-to-flange, andflange-to-flange joints shall be qualified for heat durabilityperformance through testing in accordance with Test MethodD 7247. The test temperature and heat exposure duration forspecimens tested at e
31、levated temperature (Section 7.2 ofMethod D 7247) shall meet the requirements of Items (1), (2),and (3) below.(1) For the bonded specimens, the minimum target bond-line temperature shall be 220C (428F). For the matched solidwood control specimens, the minimum target temperature atthe shear plane sha
32、ll be 220C (428F).(2) The minimum target temperatures of Item 1 shall bemaintained for a minimum of 10 minutes or until achieving aresidual strength ratio for the solid wood control specimens of30 6 10 %, whichever is longer.(3) Block shear testing shall be conducted immediatelyafter removal from th
33、e oven such that the time interval from theremoval of the test specimen from the oven to the failure of theblock shear specimen shall not exceed 60 s for each specimen5Available fromAmerican Lumber Standard Committee (ALSC), P.O. Box 210,Germantown, MD 20874, http:/www.alsc.org; and Canadian Lumber
34、StandardsAccreditation Board (CLSAB), 960 Quayside Drive, Suite 406, New Westminster,BC V3M 6G2, Canada, http:/www.clsab.ca.6Available from National Lumber Grades Authority (NLGA), 302960 Quay-side Drive, New Westminster, BC V3M 6G2, Canada, http:/www.nlga.org.D5055082tested. The room temperature of
35、 the test laboratory at the timeof testing shall not be less than 15.5C (60F).NOTE 4The intent of setting the time interval is to prevent the testspecimen bondline or shear plane temperature from dropping more than5C (9F) prior to failure after leaving the oven.5.3.3.2 For adhesives tested in accord
36、ance with 5.3.3.1, theresidual shear strength ratio for the bonded specimens, ascalculated in accordance with Test Method D 7247, shall beequal to or higher than the lower 95 % confidence interval onthe mean residual shear strength ratio for the solid woodcontrol specimens.6. Qualification6.1 Genera
37、lThis section describes procedures, both em-pirical and analytic, for initial qualification of the structuralcapacities of prefabricated wood I-joists. Qualification is re-quired for certain common details of I-joist application sincethey often influence structural capacities. All capacities are tob
38、e reported with three significant digits. Any time significantchanges in joist or application details, manufacturing processesor material specifications occur, qualification is required, as fora new manufacturer or product line.6.1.1 TestingQualification tests shall be conducted orwitnessed by a qua
39、lified agency as defined in 8.1. All testresults are to be certified by the qualified agency.6.1.1.1 Sample SizeThe number of specimens specified in6.2, 6.3, 6.4, and 6.5 are minimums. The producer wishing toevaluate the validity of the sample size will find a procedure in4.7 of Practice D 2915.6.1.
40、1.2 Test SpecimensMaterials and fabrication proce-dures of test specimens shall be as typical of intendedproduction as can be obtained at the time of manufacturingqualification specimens.NOTE 5It is desirable to conduct preliminary tests to aid the selectionof representative specimens.6.1.1.3 Test A
41、ccuracyTests in accordance with this speci-fication are to be conducted in a machine or apparatuscalibrated in accordance with Practices E4 except that thepercentage error shall not exceed 62.0.6.1.1.4 Test MethodsMethods generally applicable to thefull-section joist tests required herein are in Gui
42、de E 529, withthe following exceptions: (1) the methods are applicable toboth qualification and quality control, (2) load rate shall be asspecified in the following sections, and (3) delays between loadincrements are not required. Required tension and compressiontests shall be substantially in accor
43、dance with Test MethodsD 198 or Test Methods D 4761 with load rates as specified inthe following sections.All test report formats and content shallbe in keeping with the intended use of the results and be agreedupon by all involved parties prior to the test.6.1.1.5 Test SafetyAll full-scale structur
44、al tests are poten-tially hazardous and appropriate safety precautions must beobserved at all times. One particular concern is the potential forlateral buckling during full-section I-joist tests and appropriatelateral restraint must be maintained at all times.6.2 Shear Capacity Qualification:6.2.1 I
45、nitial capacity shall be established from either testresults or calculations. The equations used for the calculationmethod shall be confirmed by a test program; the details ofwhich are beyond the scope of this specification. Explanationsof the statistics used in the analysis of test results, with an
46、example, are given in Appendix X4.6.2.2 Factors which influence shear capacity include webtype, thickness, and grade; web to flange joint; joint type inweb (machined, butted, glued or not, reinforced, etc.). Eachcombination of these web factors must be tested separately inaccordance with 6.2.3, unle
47、ss the critical combination in aproposed grouping is first established by test. Flange stiffnessinfluences shear strength: if a range of flange sizes is to be usedwith a given combination of web factors, all sizes must betested unless all values are to be based on tests with thesmallest flange. When
48、 a range of species or grades of eithersawn or composite lumber is to be grouped, preliminary testsshall be conducted to determine which is critical. Joists withstructural composite lumber flanges, such as LVL, must betested separately from joists with sawn lumber flanges.6.2.3 For each web factor c
49、ombination, a minimum of tenspecimens shall be tested for each critical joist depth. Criticaljoist depths are minimum and maximum product depths withapproximate 4-in. (102-mm) depth increments between. If theinstallation of specific reinforcement as defined in the manu-facturers literature is required at a certain depth to maintainproduct performance in the progression of a series of depthswithin a combination, the product must be tested at this depthplus the adjacent depth which does not require specificreinforcement.6.2.4 S
