1、Designation: D 5055 07Standard 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 4933 Guide for Moisture Conditioning of Wood andWood-Based MaterialsD 5456 Specification for Evaluation of Structural Compos-ite Lumber ProductsD 5457 Sp
9、ecification for Computing Reference Resistanceof Wood-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
10、MachinesE 529 Guide for Conducting Flexural Tests on Beams andGirders for Building ConstructionE 699 Standard Practice for Evaluation of Agencies In-volved in Testing, Quality Assurance, and Evaluating ofBuilding ComponentsIEEE/ASTM-S110 Standard for Use of the InternationalSystem of Units (SI): The
11、 Modern Metric System2.2 Other Standards:U.S. Product Standard PS-1 Structural Plywood3U.S. Product Standard PS-2 Performance Standard forWood-Based Structural-Use Panels3CSA O86 Engineering Design in WoodCSA O112.7 Resorcinol and Phenol-Resorcinal Resin Ad-hesives4CSA O112.9 Evaluation of Adhesives
12、 for Structural WoodProducts (Exterior Exposure)4CSA O151 Canadian Softwood Plywood4CSA O325.0 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 editi
13、on approved Nov. 15, 2007. Published November 2007. Originallyapproved in 1990. Last previous edition approved in 2005 as D 5055 05.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume inform
14、ation, refer to the standards Document Summary page onthe ASTM website.3Available from APA The Engineered Wood Association, 7011 South 19thStreet, Tacoma, WA 98466 and PFS Research Foundation, 2402 Daniels Street,Madison, WI 53718.4Available from Canadian StandardsAssociation, 178 Rexdale Blvd., Eto
15、bicoke,Ontario, Canada M9W 1R3.1Copyright 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)53. Terminology3.1 Def
16、inition: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 floor and roofcons
17、truction.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.NOTE 1A brief disc
18、ussion 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 Considerations4.1
19、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 Properties for Design Use
20、 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 Appendix X1.4.1.3 Tre
21、atmentsSome 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 conditions suchas in m
22、ost 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 at locations of
23、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 is structuralcom
24、posite 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 purchased flange stock
25、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 U.S. Product Standard PS-1 orCSA O151, and U.S. Product Standar
26、d PS-2 or CSA O325.0.In addition, all panels shall meet the equivalent of Exposure Irequirements 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
27、) 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. Appendix X3gives additional information and standards that shall be con-sidered
28、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 wood material surrounding the joint does notprovide thermal protection.5.3.1 Adh
29、esives 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 products used as a web shall be evaluated inaccordance with PS2 (or in Canada CSA O325
30、) 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 accordance with Test MethodD 7247. The test temperature and heat exposure duration
31、forspecimens tested at elevated temperature (Section 7.2 ofMethod D 7247) shall meet the requirements of Items 1 and 2below.(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 s
32、hear 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 6 10 %, whichever is longer.5.3.3.2 For adhesives tested in accordance with 5.3.3.1, ther
33、esidual shear strength ratio for the bonded specimens, ascalculated in accordance with Test Method D 7247, shall be5Available fromAmerican Lumber Standard Committee (ALSC), P.O. Box 210,Germantown, MD 20874. Canadian Lumber Standards Accreditation Board(CLSAB), 1055 W. Hastings St., Vancouver, BC, C
34、anada V6E 2E9.D5055072equal to or higher than the lower 95 % confidence interval 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 structuralcapacit
35、ies 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 reported with three significant digits. Any time significantchanges in joist or application details, manufacturing
36、 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 agency as defined in 8.1. All testresults are to be certified by the qualified agency.6.1.1.1 Sample SizeThe
37、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 2915.6.1.1.2 Test SpecimensMaterials and fabrication proce-dures of test specimens shall be as typical of intendedproduction
38、as can be obtained at the time of manufacturingqualification specimens.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 accor
39、dance 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 are applicable toboth qualification and quality control, and
40、; (2) load rate shallbe as specified in the following sections, and; (3) delaysbetween load increments are not required. Required tensionand compression tests shall be substantially in accordance withTest Methods D 198 or Test Methods D 4761 with load rates asspecified in the following sections. All
41、 test report formats andcontent shall be in keeping with the intended use of the resultsand be agreed upon 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 part
42、icular 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 testresults or calculations. The equations used for the calc
43、ulationmethod 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 influence shear capacity include webtype, thickness, an
44、d 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 established by test. Flange stiffnessinfluences sh
45、ear 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 lumber is to be grouped, preliminary testsshall be c
46、onducted 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
47、 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 combina
48、tion, the product must be tested at this depthplus the adjacent depth which does not require specificreinforcement.6.2.4 Specimen length shall be that which usually producesfailures in shear and shall not extend past each bearing supportmore than14 in.The bearing length shall be adequate to usuallyp
49、roduce shear failure instead of a bearing failure but shall notexceed 4 in. (102 mm), unless justified. There shall be aminimum horizontal distance of 112 times the joist depthbetween the face of the support and the edge of the load pad.6.2.5 On one end of the specimen, a vertical web joint, ifused, shall be located approximately 12 in. (305 mm) from theface of the support or12 the distance between the support andthe load pad.6.2.6 The load shall be applied to the top flange either as asingle point load at center span or as two point loads of equaldist
