ASTM_D_7746_-_11.pdf

Designation:D774611Standard Practice forCalculating the Superimposed Load on Wood-frame Floor-Ceiling Assemblies for Standard Fire-Resistance Tests1This standard is issued under the fixed designation D7746;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,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 This practice covers procedures for calculating thesuperimposed load required to be applied to load-bearingwood-frame floor-ceiling assemblies throughout standard fire-resistance tests.1.2 These calculations determine the maximum superim-posed load to be applied to the floor-ceiling assembly duringthe fire resistance test.The maximum superimposed load,calculated in accordance with nationally-recognized structuraldesign criteria,shall be designed to induce the maximumallowable stress in the wood floor-ceiling fire test configurationbeing tested.1.3 This practice is only applicable to those wood-framefloor-ceiling assemblies for which the nationally recognizedstructural design criteria are the NDS(National Design Speci-fication for Wood Construction).1.4 The text of this standard references notes and footnoteswhich provide explanatory material.These notes and footnotes(excluding those in tables and figures)shall not be consideredas requirements of the standard.1.5 The values stated in inch-pound units are to be regardedas standard.No other units of measurement are included in thisstandard.1.6 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-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D9 Terminology Relating to Wood and Wood-Based Prod-uctsD6513 Practice for Calculating the Superimposed Load onWood-frame Walls for Standard Fire-Resistance TestsE119 Test Methods for Fire Tests of Building Constructionand MaterialsE176 Terminology of Fire StandardsE1529 Test Methods for Determining Effects of Large Hy-drocarbon Pool Fires on Structural Members and Assem-blies2.2 Other Standards:3NDS National Design Specification for Wood ConstructionNDS Supplement Design Values for Wood Construction3.Terminology3.1 DefinitionsDefinitions used in this practice are inaccordance with Terminology D9 and Terminology E176,unless otherwise indicated.3.2 Definitions of Terms Specific to This Standard:3.2.1 gross area,nsection area calculated from overallactual dimensions of member.3.2.2 net section area,nsection area calculated by deduct-ing from the gross section area the projected area of allmaterials removed by boring,grooving,dapping,notching,orother means.3.2.3 superimposed load,nthe additional external loadneeded to be applied to the assembly to result in the calculatedstresses within the assembly when any dead load of theassembly itself is accounted for in the calculations.4.Significance and Use4.1 Test Methods E119,E1529,and other standard fireresistance test methods specify that throughout the fire-resistance test,a constant superimposed load shall be applied toa load-bearing test specimen to simulate a maximum loadcondition.This superimposed load shall be the maximum loadallowed by design under nationally recognized structuraldesign criteria for the tested floor configuration(that is,joistselection,spacing,and span).1This practice is under the jurisdiction of ASTM Committee D07 on Wood andis the direct responsibility of Subcommittee D07.05 on Wood Assemblies.Current edition approved Nov.15,2011.Published March 2012.DOI:10.1520/D774611.2For 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 American Wood Council(AWC),803 Sycolin Road,Suite 201,Leesburg,VA 20175,http:/www.awc.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.1.1 For this Practice,the nationally recognized structuraldesign criteria to be used to determine the maximum loadcondition are those for allowable stress design in the NDS(National Design Specification for Wood Construction).4.1.2 Alternatively,the standard fire resistance test methodsshall be permitted to be conducted by applying a load less thanthe maximum allowable load in 4.1.1 for the tested configura-tion;however,these tests shall be identified in the test report asbeing conducted under restricted loading conditions.4.2 This practice describes procedures for calculating thesuperimposed load to be applied in standard fire resistance testsof wood floor-ceiling assemblies.Practice D6513 provides asimilar methodology for calcul