1、Designation: D 5055 08aStandard 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 revi
2、sion, 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 structura
3、l 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
4、main 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 determ
6、ine 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 Pr
7、operties 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 P
8、ractice 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
10、Beams andGirders 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-
11、1 Structural PlywoodPS-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 S
12、oftwood Plywood4CSA 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 15, 2008. Published June 2008. Originallyapproved in
13、 1990. Last previous edition approved in 2008 as D 5055 08.2For 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.3A
14、vailable 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), 5060 Spectrum Way,Mississauga, ON L4W 5N6, Canada, http:/www.csa.ca.1Copyrig
15、ht ASTM International, 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 FlangeStoc
16、k Lumber, 200163. Terminology3.1 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
17、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 resultof certain calculations specified in this specification.3.2.2 design valuethe numeric value claimed by themanufacturer as appropriate for use in st
18、ructural analysis.NOTE 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 con
19、ditions.4. Design Considerations4.1 Design Value Adjustments:4.1.1 Duration of LoadWith the exception of reactiondesign values limited by compression perpendicular to grain,prefabricated wood I-joists shall be designed using the strengthadjustment for load duration used in sawn lumber. Thisadjustmen
20、t is determined in accordance with the section onDuration of Load Under Modification of Allowable Propertiesfor 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
21、factorto unity primarily for purposes of design simplicity. A discussion of thisdecision is given in Appendix 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
22、 EnvironmentThe capacities developed in this speci-fication are applicable to joists used under dry conditions 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
23、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 reinforcements areprovided must be substantiated by independent testing to thegeneral intended criteria for shear capacity herein.5. Materials5.1 Flange Stock
24、:5.1.1 All flange material shall conform to the requirementsof 6.4. In addition, when the flange material 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-j
25、oist),compression (parallel and perpendicular to grain), and naildesign values.5.1.2 End joints in purchased 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
26、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 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
27、 to the requirementsin Specification D 2559 (or in Canada to Clause 13 ofCSA O86) for use under exterior (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.
28、Appendix X3gives additional information and standards that shall be con-sidered when qualifying adhesives 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
29、wood material surrounding the joint does notprovide thermal protection.5.3.1 Adhesives and binder systems 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 produc
30、ts used as a web shall be evaluated inaccordance with PS-2 (or in Canada CSA O325) with theExposure 1 classification.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 ac
31、cordance with Test MethodD 7247. The test temperature and heat exposure duration forspecimens tested at elevated temperature (Section 7.2 of TestMethod D 7247) shall meet the requirements of Items 1, 2, and3 below.(1) For the bonded specimens, the minimum target bond-line temperature shall be 220C (
32、428F). For the matched solidwood control specimens, the minimum target temperature atthe shear plane shall 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
33、 6 10 %, whichever is longer.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, Canada, http:/www.clsab.ca.6Available fr
34、om National Lumber Grades Authority (NLGA), 302960 Quay-side Drive, New Westminster, BC V3M 6G2, Canada, http:/www.nlga.org.D 5055 08a2(3) Block shear testing shall be conducted immediatelyafter removal from the oven such that the time interval from theremoval of the test specimen from the oven to t
35、he failure of theblock shear specimen shall not exceed 60 s for each specimentested. The room temperature of 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 f
36、rom dropping more than5C (9F) prior to failure after leaving the oven.5.3.3.2 For adhesives tested in accordance 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 inte
37、rval onthe mean residual shear strength ratio for the solid woodcontrol specimens.6. Qualification6.1 GeneralThis 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 c
38、ommon details of I-joist application sincethey often influence structural capacities. All capacities are tobe reported with three significant digits. Any time significantchanges in joist or application details, manufacturing processesor material specifications occur, qualification is required, as fo
39、ra new manufacturer or product line.6.1.1 TestingQualification tests shall be conducted orwitnessed by a qualified 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, 6.5, and 6.6 are minimums. Th
40、e producer wishingto evaluate the validity of the sample size will find a procedurein 4.7 of Practice D 2915.6.1.1.2 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.
41、 Minimum specimen temperature atthe time of test shall be 40F (4C). Specimens shall be testedat the as-received moisture content.NOTE 5It 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
42、 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 Guide E 529, withthe following exceptions: (1) the methods ar
43、e 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 accordance with Test MethodsD 198 or Test Methods D 4761 with l
44、oad 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 structural tests are poten-tially hazardous and appropriate safety
45、 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 Initial capacity shall be established from either testresul
46、ts 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 anexample, are given in Appendix X4.6.2.2 Factors which infl
47、uence 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, unless the critical combination in aproposed grouping is first
48、 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 a range of species or grades of eithersawn or composite l
49、umber 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 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 lite
