1、Designation: D 5055 09Standard 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 () indicates an editorial change since the last revision or reapproval.1. Scope1.1 GeneralThis specification gives procedures for estab-lishing, monitoring, and reevaluating structural
3、 capacities ofprefabricated wood I-joists. Capacities considered are shear,reaction, moment, and stiffness. Procedures for establishingcommon details are given and certain design considerationsspecific to wood I-joists are itemized.1.2 Contents of the StandardAn index and brief descrip-tion of the m
4、ain features of 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
5、units that are provided 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 determi
6、ne the applica-bility 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 Pro
7、perties for Visually 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 Pr
8、actice for Evaluating 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-
9、Based Materials 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 B
10、eams andGirders for Building ConstructionE 699 Practice for Evaluation of Agencies Involved inTesting, Quality Assurance, and Evaluating of BuildingComponentsIEEE/ASTM SI 10 Standard for Use of the InternationalSystem of Units (SI): The Modern Metric System2.2 U.S. Product Standards:3PS-1 Structural
11、 PlywoodPS-2 Performance Standard for Wood-Based Structural-UsePanels2.3 Other Standards:CSA O86 Engineering Design in Wood4CSA Standards for Wood Adhesives O112 SeriesCSA O151 Canadian Softwood Plywood4CSA O325 Construction Sheathing4Lumber Grading Rules Approved by American LumberStandards Committ
12、ee (ALSC) or Canadian Lumber Stan-dards Accreditation Board (CLSAB)5SPS-4 Special Products Standard for Fingerjointed Flange1This 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
13、 edition approved March 1, 2009. Published April 2009. Originallyapproved in 1990. Last previous edition approved in 2008 as D 5055 08ae1.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume
14、information, refer to the standards Document Summary page onthe ASTM website.3Available from APAThe 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
15、), 5060 Spectrum Way,Mississauga, ON L4W 5N6, Canada, http:/www.csa.ca.5Available from American Lumber Standard Committee (ALSC), P.O. Box 210,Germantown, MD 20874, http:/www.alsc.org; and Canadian Lumber StandardsAccreditation Board (CLSAB), 960 Quayside Drive, Suite 406, New Westminster,BC V3M 6G2
16、, Canada, http:/www.clsab.ca.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Stock Lumber, 200163. Terminology3.1 Definition:3.1.1 prefabricated wood I-joista structural membermanufactured using sawn or structural composite lumberfla
17、nges 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 floor and roofconstruction.3.2 Definitions of Terms Specific to This Standard:3.2.1 capacity (or structural capacity)the numeric resul
18、tof certain calculations specified in this specification.3.2.2 design valuethe numeric value claimed by themanufacturer as appropriate for use in structural analysis.NOTE 1A brief discussion of this issue is found in X1.9.3.2.3 structural composite lumbera composite of woodelements (for example, woo
19、d strands, strips, veneer sheets, ora combination thereof), bonded with an exterior grade adhesiveand intended for structural use in dry service conditions.4. Design Considerations4.1 Design Value Adjustments:4.1.1 Duration of LoadWith the exception of reactiondesign values limited by compression pe
20、rpendicular to grain,prefabricated wood I-joists shall be designed using the strengthadjustment for load duration used in sawn lumber. Thisadjustment is determined in accordance with the section onDuration of Load Under Modification of Allowable Propertiesfor Design Use in Practice D 245.4.1.2 Repet
21、itive 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 Appendix X1.4.1.3 TreatmentsSome pressure treatment
22、s 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 conditions suchas in most covered structures.Appropr
23、iate 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 at locations of continuity or where reinforcem
24、ents 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 6.4. In addition, when the flange material is structuralcomposite lumber, the following p
25、roperties 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 purchased flange stock are permittedprovided such joi
26、nts 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 addition, all panels shall meet the equivalent o
27、fExposure 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, shall conform to anappropriate standard from the CSA Standards for Wood Adhe-sives, O112 Ser
28、ies, stipulated in CSA O86). In addition,adhesives used for web-to-web, web-to-flange, and flange-to-flange joints shall be qualified for heat durability performancein accordance with 5.3.3. Appendix X3 gives additional infor-mation and standards that shall be considered when qualifyingadhesives and
29、 adhesive-bonded materials.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 used
30、 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 classi
31、fication.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 elev
32、ated temperature (7.2 of Test MethodD 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 428F (220C). For the matched solidwood control specimens, the minimum target temperature atthe shear plane shall be 428F
33、(220C).(2) The minimum target temperatures of Item 1 shall bemaintained for a minimum of 10 min 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 the oven such tha
34、t the specimen bondline orshear plane temperature does not drop more than 9F (5C)after leaving the oven and prior to failure. This provision issatisfied when the time interval from the removal of thespecimen from the oven to the failure of the block shearspecimen does not exceed 60 s for each specim
35、en tested andthe room temperature of the test laboratory at the time oftesting is not less than 60F (15.5C).6Available from National Lumber Grades Authority (NLGA), 302960 Quay-side Drive, New Westminster, BC V3M 6G2, Canada, http:/www.nlga.org.D50550925.3.3.2 For adhesives tested in accordance with
36、 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 GeneralThis sec
37、tion 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 tobe reporte
38、d 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 qualified ag
39、ency 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, 6.5, and 6.6 are minimums. The producer wishingto evaluate the validity of the sample size will find a procedurein 4.7 of Practice D 2915.6.1.1.2
40、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. Minimum specimen temperature atthe time of test shall be 40F (4C). Specimens shall be testedat the as-received moist
41、ure content.NOTE 4It is desirable to conduct preliminary tests to aid the selectionof representative specimens.6.1.1.3 Test AccuracyTests in accordance with this speci-fication are to be conducted in a machine or apparatuscalibrated in accordance with Practices E4 except that thepercentage error sha
42、ll not exceed 62.0.6.1.1.4 Test MethodsMethods generally applicable to thefull-section joist tests required herein are in Guide 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,
43、and (3) delays between loadincrements are not required. Required tension and compressiontests shall be substantially in accordance 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 inten
44、ded use of the results and be agreedupon by all involved parties prior to the test.6.1.1.5 Test SafetyAll full-scale structural tests are poten-tially hazardous and appropriate safety precautions must beobserved at all times. One particular concern is the potential forlateral buckling during full-se
45、ction I-joist tests and appropriatelateral restraint must be maintained at all times.6.2 Shear Capacity Qualification:6.2.1 Initial capacity shall be established from either testresults or calculations. The equations used for the calculationmethod shall be confirmed by a test program; the details of
46、which are beyond the scope of this specification. Explanationsof the statistics used in the analysis of test results, with anexample, 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,
47、glued or not, reinforced, etc.). Eachcombination of these web factors must be tested separately inaccordance with 6.2.3, unless 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
48、 combination of web factors, all sizes must betested unless all values are to be based on tests with thesmallest flange. When 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 com
49、posite lumber flanges, such as laminated veneerlumber (LVL), must be tested separately from joists with sawnlumber flanges.6.2.3 For each web factor combination, 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 s
