ASTM D7470-2008 923 Standard Practice for Evaluating Elevated Temperature Performance of End-Jointed Lumber Studs《端拼木螺栓高温性能评价的标准实施规程》.pdf

1、Designation: D 7470 08Standard Practice forEvaluating Elevated Temperature Performance of End-Jointed Lumber Studs1This standard is issued under the fixed designation D 7470; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year

2、 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 This practice is to be used to evaluate the elevatedtemperature performance of end-jointed lumber studs.1.2 Asymme

3、tric wall assembly containing end-jointed lum-ber studs is exposed to a standard fire exposure specified inTest Methods E119.1.3 End-jointed lumber studs are deemed qualified if thewall assembly resists a standard fire exposure specified in TestMethods E119for a period of 60 min or more. Qualificati

4、on ofend-jointed lumber studs are restricted to the joint configura-tion and adhesive tested.1.4 This practice is used to evaluate the performance ofend-jointed lumber studs to heat and flame under controlledconditions, but does not by itself incorporate all factorsrequired for fire hazard or fire r

5、isk assessment under actual fireconditions.1.5 The values stated in inch-pound units are to be regardedas the standard. The values given in parentheses are forinformation only.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsib

6、ility 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:2C 1396/C 1396M Specification for Gypsum BoardD 4688 Test Method for Evaluating Structural Adhesi

7、vesfor Finger Jointing LumberD 6513 Practice for Calculating the Superimposed Load onWood-frame Walls for Standard Fire-Resistance TestsE119 Test Methods for Fire Tests of Building Constructionand MaterialsF 1667 Specification for Driven Fasteners: Nails, Spikes,and Staples2.2 Other Standards:NDS Na

8、tional Design Specification for Wood Construction33. Terminology3.1 Definitions:3.1.1 end-jointed lumberLumber containing one or moreend-joints3.1.2 end-jointsa joint formed by bonding two pieces oflumber end-to-end, often by machining a set of interlocking“fingers” (finger-joint) into each end of a

9、djoining pieces, usingan adhesive to form an adhesive bonded joint.3.1.3 qualified agencyan organization, hereafter referredto as the agency, that has trained personnel and procedures toensure the grades comply with all applicable requirements ofthis practice. The agency shall have no financial inte

10、rest in, norshall be financially dependent upon, any single companymanufacturing the product being inspected or tested; and shallnot be owned, operated, or controlled by any such company.4. Summary of Practice4.1 This practice shall be used to evaluate end-jointedlumber studs manufactured with a spe

11、cific joint configurationand adhesive. This practice is intended to be limited to theevaluation of end-jointed lumber studs with a specific jointconfiguration, adhesive, and limited design properties. Theresults are only applicable to end-jointed lumber studs using ajoint configuration with the same

12、 number of fingers and afinger length of at least equal length as qualified in 7.1.2 andshall have assigned design properties no greater than the gradelevel qualified in 7.1.2.5. Significance and Use5.1 End-jointed lumber studs used in fire resistance-ratedassemblies shall be able to support the sup

13、erimposed designload for the specified time under an elevated temperatureexposure, when a wall assembly is exposed to a standard fire1This practice is under the jurisdiction of ASTM Committee D07 on Wood andis the direct responsibility of Subcommittee D07.02 on Lumber and EngineeredWood Products.Cur

14、rent edition approved Aug. 1, 2008. Published September 2008.2For 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.

15、3Available from American Wood Council (AWC), 1111 Nineteenth Street, NW,Suite 800, Washington, DC 20036, http:/www.awc.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.specified in Test Methods E119. Light-weight wood assem-blies

16、utilize gypsum wallboard or other types of membraneprotection to accomplish a requisite fire resistance rating forthe assembly. However, wood studs and the end-joints in thestuds shall resist the developed elevated temperature environ-ment for the duration of the rating. This practice provides ameth

17、od for evaluating the elevated temperature performance ofan assembly constructed with end-jointed studs having fireperformance comparable to an assembly constructed withsolid-sawn studs.6. Wall Assembly6.1 A load-bearing wall meeting the following assemblydescription shall be used:6.1.1 Framing Elem

18、ents:6.1.1.1 StudsNine pieces of 2 by 4 (nominal) end-jointedlumber shall be used for wall studs. Each piece of end-jointedlumber shall be 115.5 in. (2934 mm) long and have at least oneend-joint within the middle third of the length. Studs shall besymmetrically placed within the 10-ft (3 m) long by

19、10-ft (3 m)high wall assembly with interior studs spaced 16 in. (406 mm)on center as shown in Fig. 1. The moisture content of theend-jointed lumber shall be no greater than 15 % at the time ofthe fire test.NOTE 1When producing end-jointed lumber for use in this standardpractice, consideration should

20、 be given to the unique production condi-tions, such as wood moisture content, applied spread rate, pressure, andcuring temperature of the adhesive in accordance with the adhesivemanufacturers recommendations.6.1.1.2 PlatesStuds shall be attached to a double top plateand a single bottom plate as sho

21、wn in Fig. 1. Plates shall be thesame species as the stud material. The first top plate and thebottom plate shall be attached to the studs using 2-16d commonnails or 3-16d box nails. The second top plate is attached to thefirst top plate using a single row of 16d common nail at 16 in.(406 mm) on cen

22、ter or 1-16d box nails at 12 in. (305 mm) oncenter. Nails shall be in accordance with Specification F 1667.NOTE 2In Fig. 1, double top plates are located at the bottom of testwall to be adjacent to the movable load beam. Double top plates arelocated at the top of the test wall when the load beam is

23、along the top.6.1.1.3 BlockingBlocking between studs shall not bepermitted.6.1.2 InsulationThe cavity between studs shall be filledwith 3-in. (89-mm) thick mineral wool insulation having anominal density of 2.5 pcf (40 kg/m3).6.1.3 SheathingA single layer of #-in. (16-mm) Type Xgypsum wallboard (in

24、accordance with Specification C 1396/C 1396M), 4 ft (1.22 m) wide, shall be applied to each side ofthe assembly with the long axis perpendicular to the studs asshown in Fig. 1. Horizontal joints shall be unblocked. Novertical joints are required.6.1.4 FastenersGypsum wallboard shall be attached to a

25、llframing members, including top and bottom plates, as shown inFIG. 1 Assembly DetailsD7470082Fig. 1 using 2-in. (57-mm) Type S drywall screws spaced 12in. (305 mm) on center.NOTE 3Screws have been shown to increase the temperature in thesurrounding wood and insertion into end-joints should be minim

26、ized.6.1.5 Joints and Fastener HeadsOn both faces of thewall, all wallboard joints shall be covered with paper tape andjoint compound and fastener heads shall be covered with jointcompound.7. Loading7.1 The superimposed load on the wall assembly throughoutthe fire resistance test shall be nine times

27、 the load per studcalculated in 7.1.2.7.1.1 Joint Strength QualificationAn agency shall qualifythe sample of end-jointed lumber for the highest grade for thespecies being tested. The lumber used for the vertical framingin the fire test wall assembly shall be selected from the lot usedto qualify the

28、joint strength.NOTE 4In the United States and Canada, criteria for agency accredi-tation are contained in PS-20, and CSA O141, respectively.NOTE 5In the United States, the minimum strength qualificationrequirements for end-jointed lumber are given in theALSC Glued LumberPolicy.7.1.2 Load Calculation

29、The load per stud shall be calcu-lated using 100 % of the adjusted compression design valueparallel to grain (Fc8) calculated in accordance with theprocedures of Practice D 6513 for the highest grade qualified in7.1.1. The load per stud shall be calculated using minimumdressed size dimensions 1.5 in

30、. (38 mm) by 3.5 in. (89 mm).NOTE 6The design values parallel-to-grain (Fc8) in Appendix A ofPractice D 6513 are calculated using ANSI/AF end-joint; end-jointed lumber; qualificationASTM International takes no position respecting the validity of any patent rights asserted in connection with any item

31、 mentionedin this standard. Users of this standard are expressly advised that determination 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 commi

32、ttee and must be reviewed every five years andif not revised, either reapproved or withdrawn. 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 me

33、eting of theresponsible technical committee, which you may attend. If you feel that your comments 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,

34、 PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or 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).D7470083