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AmericAn nAtionAl stAndArds institute/ steel deck institute
Composite Steel Floor Deck
STEEL DECKINSTITUTE
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copyright 2007 steel deck institute
C1.0 - 2006 Standard for
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Composite Steel Floor DeckC1.0 - 2006 Standard for
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1. General
1.1 Scope: A.ThisspecificationforComposite SteelDeckshallgovernthe materials,design,and erectionofcoldformed steeldeckwhichactsasa permanentformandas positivereinforcement forastructuralconcreteslab.
B. Commentaryshallnotbe consideredpartofthe mandatorydocument.
1.2 Reference Codes, Standards and Documents: A.CodesandStandards: ForpurposesofthisStandard, complywithapplicable provisionsofthefollowing CodesandStandards:
1.AmericanIronandSteel Institute(AISI)Standard-North AmericanSpecificationfor theDesignofCold-Formed SteelStructuralMembers,2001 EditionwithSupplement2004
2.AmericanWeldingSociety- ANSI/AWSD1.3Structural WeldingCode/SheetSteel-98 StructuralWeldingCode- SheetSteel
3.AmericanSocietyforTesting andMaterials(ASTM)A653 (A653M)-06,A924(A924M)-06, A1008(A1008M)-06,A820 (A820M)-06,C1399(C1399M)- 04,TestMethodE2322-03, ASTMSubcommitteeCO9.42
4.AmericanConcreteInstitute (ACI)BuildingCode RequirementsforReinforced Concrete–ACI318-05
5.AmericanSocietyofCivilEngi- neering(ASCE)-SEI/ASCE7-05
6.AmericanInstituteofSteel Construction(AISC)- SpecificationforStructural SteelBuildings,13thEdition
7.UnderwritersLaboratories (UL)FireResistanceDirectory- http://www.ul.com/database 2006
Commentary:Manyfire relatedassembliesthatuse compositefloordecksare available.IntheUnderwriters LaboratoriesFire Resistance Directory,thecompositedeck constructionsshowhourly ratingsforrestrainedand unrestrainedassemblies.ASTM E119providesinformationin appendixX3called“Guidefor DeterminingConditionsof RestraintforFloorandRoof Assembliesandfor IndividualBeams”.
B. ReferenceDocuments: Refertothefollowing documents:
1.SDICompositeDeckDesign Handbook-CDD2-1997 2.SDIManualofConstruction withSteelDeck-MOC2-2006
3.SDIStandardPracticeDetails- SPD2-2001
4.SDIDiaphragmDesign Manual-DDMO3-2004
2. Products2.1 Material: A.Sheetsteelforgalvanizeddeck shallconformtoASTMA653 (A653M)StructuralQuality,with aminimumyieldstrengthof 33ksi(230MPa).
B. Sheetsteelforuncoatedor phosphatizedtop/painted bottomdeckshallconformto ASTMA1008(A1008M)with aminimumyieldstrengthof 33ksi(230MPa).Other structuralsheetsteelsorhigh strengthlowalloysteelsare acceptable,andshallbe selectedfromtheNorth American Specification for the Design of Cold-Formed Steel Structural Members.
C.Sheetsteelforaccessoriesshall conformtoASTMA653 (A653M)-minimumyield strengthof33ksi(230MPa). StructuralQualityforstructural accessories,ASTMA653(A653M) CommercialQualityfor non-structuralaccessories,or ASTMA1008(A1008M)for eitherstructuralor non-structuralaccessories. Otherstructuralsheetsteelsor highstrengthlowalloysteels areacceptable,andshallbe selectedfromtheNorth American Specification for the Design of Cold-Formed Steel Structural Members.
D.Thedecktype(profile)and thickness(gage)shallbeas shownontheplans.
Commentary:Mostcomposite steelfloordeckismanufactured fromsteelconformingtoASTM DesignationA1008(A1008M), Grades33and40,orfromA653 (A653M),StructuralSheetSteel. Whenspecifyingalternative steels,certainrestrictionsapply (SeeNorth American Specification for the Design of Cold-Formed Steel Structural MembersSection A2-3.2).2.1Areferstotheuseof galvanizeddeckwhile2.1Brefers totheuseofuncoatedor phosphatizedtop/painted undersidedeck.Inmostcasesthe designerwillchooseonefinishor theother.However,bothtypesof finishmaybeusedonajob,in whichcasethedesignermust indicateontheplansandproject specificationstheareasinwhich eachisused.(RefertoSection2.3 andthecommentaryofthese specifications).Insection2.1D,the decktypeistheparticularprofileof deckchosenbythedesigner.
2.2 Tolerance: A.Uncoatedthicknessshallnotbe lessthan95%ofthedesign thicknessaslistedinTable2.2.1:
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B.Panellengthshallbewithinplus orminus1/2inch(12mm)of specifiedlength.
C.Panelcoverwidthshallbeno greaterthanminus3/8inch (10mm),plus3/4inch(20mm).
D.Panelcamberand/orsweep shallbenogreaterthan1/4inch in10footlength(6mmin3m).
E.Panelendoutofsquareshall notbegreaterthan1/8inchper footofpanelwidth(10mmperm).
2.3 Finish: A.Galvanizingshallconformto ASTMA653(A653M).
B. Uncoatedorphosphatized topsidewithpaintedunderside shallbeappliedtosteelsheet conformingtoASTMA1008 (A1008M).
C.Thefinishonthesteel compositedeckshallbe suitablefortheenvironment ofthestructure.
Commentary:Thefinishonthe steelcompositedeckshallbeas specifiedbythedesignerandbe suitablefortheenvironmentof thestructure.Sincethecomposite deckisthepositivebending reinforcementfortheslab,itmust bedesignedtolastthelifeofthe structure.Agalvanizedfinish equaltoASTMA653(A653M)-G30 minimumisrecommended. Whencompositedeckwitha phosphatizedtopandpainted bottomisused,theprimercoat isintendedtoprotectthesteel foronlyashortperiodof exposureinordinaryatmospheric conditionsandshallbe
consideredanimpermanentand provisionalcoating.
2.4 Design: A.Deckasaform
1.Thesectionpropertiesfor thesteelfloordeckunit(asa forminbending)shallbe computedinaccordancewith theNorth American Specification for the Design of Cold-Formed Steel Structural Members.
2.AllowableStressDesign(ASD): Bendingstressshallnotexceed 0.60timestheyieldstrength, norexceed36ksi(250MPa) underthecombinedloads ofwetconcrete,deckweight, andthefollowingconstruction liveloads:20poundsper squarefoot(1kPa)uniform loador150poundconcentrated loadona1’-0”(300mm)wide sectionofdeck(2.2kNperm). Theinteractionofshearand bendingshallbeconsideredin thecalculations. (SeeFigure1-AttachmentC1)
3.LoadandResistance FactorDesign(LRFD):Theload combinationsforconstruction areasshowninAttachmentC1. Loadfactorsshallbein accordancewithASCE7(See Section1.2.A.5).The resistancefactorsandnominal resistancesshallbein accordancewithNorth American Specification for the Design of Cold-Formed Steel Structural Members.
Commentary:Theloadingshown inFigure1ofAttachmentC1is representativeofthesequential loadingofwetconcreteonthe deck.The150poundload(perfoot ofwidth)istheresultofdistributing a300pound(1.33kN)manovera 2foot(600mm)width.Experience hasshownthistobeaconservative distribution.Themetricequivalent ofthe150poundloadis2.2kNper meterofwidth.Forsinglespan deckconditions,theabilityto controltheconcreteplacement
mayberestrictedandan amplificationfactorof1.5isapplied totheconcreteloadtoaddressthis condition;however,inordertokeep this50%loadincreasewithina reasonablelimit,theincreaseisnot toexceed30psf(1.44kPa).InLRFD, aloadfactorforconstructionof1.4 isappliedtothisload.Whenever possible,thedeckshallbe multi-spanandnotrequireshoring duringconcreteplacement.
4.DeckDeflection:Calculated deflectionsofthedeck,asa form,shallbebasedonthe loadofthewetconcreteas determinedbythedesignslab thicknessandtheweightof thesteeldeck,uniformly loadedonallspans,andshall belimitedto1/180ofthe clearspanor3/4inch (20mm),whicheverissmaller. Calculateddeflectionsshallbe relativetosupportingmembers.
Commentary:Thedeflection calculationsdonottakeinto accountconstructionloads becausetheseareconsidered temporaryloads.Thedeckis designedtoalwaysbeintheelastic rangesoremovaloftemporary loadsshouldallowthedeckto recover.Thestructuralsteelalso deflectsundertheloadingofthe wetconcrete.
Thedesignerisurgedtocheck thedeflectionofthetotalsystem, especiallyifcompositebeams andgirdersarebeingused.Ifthe designerwantstoinclude additionalconcreteloadingonthe deckbecauseofframedeflection, theadditionalloadshouldbe shownonthedesigndrawingsor statedinthedecksectionofthe jobspecifications.
5.MinimumBearing:Minimum interiorbearinglengthsshall bedeterminedinaccordance withthewebcrippling provisionsoftheNorth American Specification for the Design of Cold-Formed Steel Structural Members;auniform
Table 2.2.1 Gage Design Minimum No. Thickness Thickness in. mm. in. mm. 22 0.0295 0.75 0.028 0.71 21 0.0329 0.84 0.031 0.79 20 0.0358 0.91 0.034 0.86 19 0.0418 1.06 0.040 1.01 18 0.0474 1.20 0.045 1.14 17 0.0538 1.37 0.051 1.30 16 0.0598 1.52 0.057 1.44
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Composite Steel Floor DeckC1.0 - 2006 Standard for
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loadingcaseofwetconcrete, plustheweightofthesteel deck,plus20psf(1kPa) constructionloadshallbeused. (SeeFigure3-AttachmentC1)
Commentary:Experience hasshownthat1-1/2inches (38mm)ofbearingissufficient forcompositefloordecks.If lessthan1-1/2inches(38mm)of endbearingisavailable,orifhigh supportreactionsareexpected, thedesignprofessionalshould checkthedeckwebcrippling capacity.Thedeckmustbe adequatelyattachedtothe structuretopreventslipoff.
6.DiaphragmShearCapacity: Diaphragmswithoutconcrete shallbedesignedinaccordance withtheSDIDiaphragm Design Manual, orfromtests conductedbyanindependent professionalengineer.
Commentary:Calculationsof diaphragmstrengthandstiffness shouldbemadeusingtheSDI Diaphragm Design Manual. If testingisusedasthemeansfor determiningthediaphragm strengthandstiffness,thenit shouldfollowtheAISITS7-02 testprotocol.
B. DeckandConcreteasa CompositeSlab:
1.General:The“SDIMethod” (refertoSDIComposite Deck Design Handbook)shallbe limitedtogalvanizedor topsideuncoatedsteeldecks withembossments.The embossmentpatternsshall betypicalofthemanufactured steeldeckwiththedepthofthe embossmentnotlessthan90% ofthetestedembossment depth.(RefertoAttachmentC4 forfurtherlimitations).Thecompositeslabshallbedesignedasareinforcedconcreteslabwiththesteeldeckactingasthepositive
reinforcement.Thedeckmustbesuitabletodevelopcompositeinteraction.JustificationofthisrequiresfullscaletestingasperASTME2322,orcalculationsbasedupontesting.
a. AllowableStrengthDesign (ASD)shallbepermittedasan alternatedesignmethod. (SeeSDIComposite Deck Design Handbook.)
b.Standardreinforcedconcrete designproceduresshallbeused todetermineultimateload capacity.Theallowable superimposedloadshallthen bedeterminedbydeducting theweightoftheslabandthe deck.AttachmentC4, Strength and Serviceability Determination of Composite Deck Slabshallbeusedfor strengthdetermination.
Commentary:Highconcentrated loads,diaphragmloads,etc.require additionalanalysis.Horizontal loadcapacitiescanbedetermined byreferringtotheSDIDiaphragm Design Manual.Concentratedloads canbeanalyzedbythemethods shownintheSDIComposite Deck Design Handbook. Mostpublished liveloadtablesarebasedon simplespananalysisofthe compositesystem;thatis,the slabisassumedtocrackovereach support.
2.LoadDetermination:Using standardreinforcedconcrete designprocedures,the allowablesuperimposedload shallbefoundbyusing appropriateloadand resistancedesignfactors(LRFD) andapplicablereduction factorsbasedonthepresence, absence,orspacingofshear studsonbeamsperpendicular tothedeck.(Referto AttachmentC4andC5)
Commentary:Byusingthe referenceanalysistechniquesor testresults,thedeckmanufacturer determinestheliveloadsthatcan beappliedtothecompositedeck slabcombination.Theresultsare usuallypublishedasuniformload tables.Formostapplications,the deckthicknessandprofileis selectedsothatshoringisnot required;theliveloadcapacityof thecompositesystemisusually morethanadequateforthe superimposedliveloads.In calculatingthesectionproperties ofthedeck,theAISIprovisionsmay requirethatcompressionzonesin thedeckbereducedtoan “effectivewidth,”butastensile reinforcement,thetotalareaof thecrosssectionmaybeused. (SeeattachmentC5)
Coatingsotherthanthosetested maybeinvestigated,andifthere isevidencethattheirperformance isbetterthanthatofthetested product,additionaltestingmay notberequired.
3.Concrete:Concretedesign shallbeinaccordancewiththe ACIBuilding Code Requirements for Reinforced Concrete. Minimum compressivestrength(f’c)shall beaminimumof3ksi (20MPa)orasrequiredforfire ratingsordurability. Admixturescontainingchloride saltsshallnotbeused.
Commentary:Loadtablesare generallycalculatedbyusinga concretestrengthof3ksi(20MPa). Compositeslabcapacitiesarenot greatlyaffectedbyvariationsin concretecompressivestrength; but,ifthestrengthfallsbelow 3ksi(20MPa)itwouldbeadvisable tocheckshearstudstrengths.Fire ratingrequirementsmaydictate theminimumconcretestrength. Theuseofadmixturescontaining chloridesaltsisnotallowed becausethesaltswillcorrodethe steeldeck.
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Composite Steel Floor DeckC1.0 - 2006 Standard for
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a.MinimumCover:Theminimum concretethicknessabovethe topofthesteeldeckshallbe 2inches(50mm).When additional(negativebending) reinforcementisplacedinthe slab,theminimumcoverof concreteabovethereinforcing shallbeinaccordancewiththe ACI Building Code Requirements for Reinforced Concrete.
4.Deflection:Deflectionofthe compositeslabshallnotexceed 1/360oftheclearspanunder thesuperimposedliveload.
Commentary:Liveloaddeflections areseldomadesignfactor.The deflectionoftheslab/deck combinationcanbepredictedby usingtheaverageofthecracked anduncrackedmomentsofinertia asdeterminedbythetransformed sectionmethodofanalysis.Referto AttachmentC5ofthisspecification ortheSDIComposite Deck Design Handbook.
5.SuspendedLoads:All suspendedloadsmustbe includedintheanalysisand calculationsforstrengthand deflection.
Commentary:Thedesignermust takeintoaccountthesequence ofloading.Suspendedloadsmay includeceilings,lightfixtures, ductsorotherutilities.The designermustbeinformedofany loadsappliedafterthecomposite slabhasbeeninstalled.
Careshouldbeusedduringthe placementofloadsonalltypesof hangertabsorotherhanging devicesforthesupportofceilings sothatanapproximateuniform loadingismaintained.The individualmanufacturershouldbe consultedforallowableloadingon singlehangertabs.Improperuseof hangertabsorotherhanging devicescouldresultinthe overstressingoftabsand/orthe overloadingofthecomposite deckslab.
6.Reinforcement: a.Temperatureandshrinkage reinforcement,consistingof weldedwirefabricorreinforcing bars,shallhaveaminimum areaof0.00075timesthearea oftheconcreteabovethedeck (perfootormeterofwidth), butshallnotbelessthanthe areaprovidedby6x6-W1.4x W1.4weldedwirefabric.
Fibersshallbepermittedasa suitablealternativetothe weldedwirefabricspecified fortemperatureandshrinkage reinforcement.Cold-drawn steelfibersmeetingthecriteria ofASTMA820,ataminimum additionrateof25lb/cuyd (14.8kg/cumeter),ormacro syntheticfibers“Coarsefibers” (perASTMSubcommittee CO9.42),madefromvirgin polyolefin,shallhavean equivalentdiameterbetween 0.4mm(0.016in.)and1.25mm (0.05in.),havingaminimum aspectratio(length/equivalent diameter)of50,ataminimum additionrateof4lb./cuyd (2.4kg/m3)aresuitabletobe usedasminimumtemperature andshrinkagereinforcement.
Commentary:Neitherweldedwire fabricorfiberswillprevent cracking;however,theyhave beenshowntodoagoodjob ofcrackcontrol.Theweldedwire fabricmustbeplacednearthetop oftheslab[3/4to1inchcover (20to25mm)]atsupportsand drapedtowardthecenterofthe deckspan.Ifaweldedwirefabric isusedwithasteelareagiven bytheaboveformula,itwillnot besufficientasthetotalnegative reinforcement.Iftheminimum quantityofsteelfibers,ormacro syntheticfibers,areusedfor shrinkageandtemperature reinforcement,theywillnotbe sufficientasatotalnegative reinforcement.
b.Negative:Whennegative
momentexists,thedeckshall bedesignedtoactonlyasa permanentform.
Commentary:Compositesteel deckdoesnotfunctionas compressionreinforcingsteelin areasofnegativemoment.Ifthe designerwantsacontinuousslab, thennegativebendingreinforcing shouldbedesignedusing conventionalreinforcedconcrete designtechniquesincompliance withtheACIBuilding Code Requirements for Reinforced Concrete.Theweldedwirefabric, chosenfortemperature reinforcing,maynotsupply enoughareaforcontinuity.The deckisnotconsideredtobe compressionreinforcement. Typicallynegativereinforcement isrequiredatallcantileveredslabs, orifacontinuousslabisdesired.
c.Distribution:Whenlocalized loadsexceedthepublished uniformcompositedeckload tables,thedesignershall proportiondistribution reinforcementusing conventionalconcretedesign methods.
Commentary:Distributionsteel mayberequiredinadditiontothe weldedwirefabricorsteelfibers. Concentratedloads,eitherduring constructionorin-service,arethe mostcommonexampleofthis requirement.Concentratedloads maybeanalyzedbythemethods inthelatestSDIComposite Deck Design Handbook.
7.CantileverLoads:When cantileveredslabsare encountered,thedeckacts onlyasapermanentform;top reinforcingsteelshallbe proportionedbythedesigner. Forconstructionloads,thedeck shallbedesignedforthemore severeof(a)deckplusslab weightplus20psf(1kPa) constructionloadonboth cantileverandadjacentspan,or (b)deckplusslabweighton
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bothcantileverandadjacent spanplusa150pound(665N) concentratedloadperfootof widthatendofcantilever.The loadfactorsforbending,shear, andinteriorbearingshallbeas requiredbyASCE7.Resistance factorsforbending,shear,and interiorbearingshallbein accordancewiththeNorth American Specification for the Design of Cold Formed Structural Members. Themaximumcantilever deflectionasaform,under deckplusslabweight,shallbe a/90where“a”isthecantilever length,andshallnotexceed 3/4inches(19mm).
Sidelapsshallbeattachedat theendofthecantileverand amaximumspacingof12 inches(300mm)o.c.fromthe cantileverend.Each corrugationshallbe fastenedatboththeperimeter supportandthefirstinterior support.Thedeckshallbe completelyattachedtothe supportsandatthesidelaps beforeanyloadisappliedtothe cantilever.Concreteshallnotbe placedonthecantileveruntil afterplacementontheadjacent span.
8. DiaphragmShearCapacity: Diaphragmswithconcreteshall bedesignedinaccordancewith theSDIDiaphragm Design Manual,orfromtestsconducted byanindependentprofessional engineer.
Commentary:Calculationsof diaphragmstrengthandstiffness shouldbemadeusingtheSDI Diaphragm Design Manual. If testingisusedasthemeansfor determiningthediaphragm strengthandstiffness,thenit shouldfollowtheAISITS7-02test protocol.
2.5 Accessories: A.Pourstops,columnclosures, endclosures,coverplates,and girderfillersshallbethetype suitablefortheapplication. Pourstopminimumgages shallbeinaccordancewiththe SteelDeckInstitute.(SeePour Stop Selection Table, AttachmentC2) B. Mechanicalfastenersorwelds shallbepermittedfordeckand accessoryattachment.
3. Execution3.1 Installation/ General: A. Supportframingandfield conditionsshallbeexamined forcompliancewithinstallation
tolerancesandother conditionsaffecting performanceofworkofthis section.AllOSHArulesfor erectionshallbefollowed.
B. Deckpanelsshallbeinstalled onaconcretesupport structureonlyafterthe concretehasattained75%of itsspecifieddesignstrength.
C. Deckpanelsandaccessories shallbeinstalledaccording totheSDIManual of Construction with Steel Deck, placementplans,and requirementsofthisSection.
D. Temporaryshoring,ifrequired, shallbeinstalledbefore placingdeckpanels. Temporaryshoringshallbe designedtoresistaminimum uniformloadof50psf(2.4kPa), andloadingcriteriaindicated onAttachmentC1.Shoring shallbesecurelyinplace beforethefloordeckerection begins.Theshoringshallbe designedandinstalledin accordancewiththeACI Building Code Requirements for Reinforced Concreteand shallbeleftinplaceuntilthe slabattains75%ofitsspecified
designstrengthanda minimumofseven(7)days.
E. Deckpanelsshallbeplaced onstructuralsupportsand adjustedtofinalpositionwith endsaligned,andattached securelytothesupports immediatelyafterplacement inordertoformasafeworking platform.Alldecksheetsshall haveadequatebearingand fasteningtoallsupportsto preventslipoffduring construction.Deckendsover supportsshallbeinstalled withaminimumendbearing of1-1/2inches(38mm).Deck areassubjecttoheavyor repeatedtraffic,concentrated loads,impactloads,wheel loads,etc.shallbeadequately protectedbyplankingor otherapprovedmeanstoavoid overloadingand/ordamage.
F. ButtedEnds:Deckends shallbebuttedoversupports.
Commentary:Lappingcompositedeckendscanbedifficult becauseshearlugs(web embossment)orprofileshapecanpreventatightmetalto metalfit.Thespacebetween lappedsheetscanmake weldedattachmentsmore difficult.Gapsareacceptable upto1”(25mm)atbuttedends.
G. Deckunitsandaccessoriesshall becutandneatlyfitaround scheduledopeningsandother workprojectingthroughor adjacenttothedecking.
Commentary:Itistheresponsibilityofthedesignertodesignateholes/openingstobedeckedoverincompliancewithapplicablefederalandstateOSHAdirectives.Careshouldbetakentoanalyzespansbetweensupportsatopeningswhen determiningthoseholes/openingstobedeckedover.Whenaframedopeningspanexceedsthemaximumdeckspanlimitsfor
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Composite Steel Floor DeckC1.0 - 2006 Standard for
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constructionloads,theopeningmustbedetailedaroundinsteadofdeckedover.(Minimumfloorconstructionload50lbs./sq.ft.(2.4kPa),unlessspecific requirementsdictateotherwise).
Whenaframedhole/openinginfloordeckisshownand dimensionedonthestructuraldesigndrawings,pourstop(screed)angleisrequiredtotopofslab.Whenspecified,cellclosureanglewillbeprovidedattheopenendsofdeckinstandard10’-0”(3m)lengthstobefieldsized,cutandinstalled.Alternatemeanstodamconcretemaybeusedinlieuofcellclosure,atthediscretionoftheinstaller,ifapprovedbythedesigner.
Whenahole/openingisnotshownanddimensionedonthestructuraldesigndrawings,no provisionsforconcreteretainagewillbeprovidedbythemetaldeckmanufacturer/supplier.Metalfloordeckingholesandopeningstobecutaftertheconcretepourshallnotbefieldcutuntilconcretehasreached75%ofitsdesignstrengthandaminimumofseven(7)days.
H. Tradesthatsubsequentlycut unscheduledopenings throughthedeckshallbe responsibleforreinforcing theseopeningsbaseduponan approvedengineereddesign.
3.2 Installation/Anchorage:A. Floordeckunitsshallbe anchoredtosteelsupporting membersincludingperimeter supportsteeland/orbearing wallsbyarcspotpuddlewelds ofthefollowingdiameterand spacing,filletweldsofequal strength,ormechanical fasteners.
1.Allweldingofdeckshallbein strictaccordancewithANSI/AWS D1.3,Structural Welding Code- Sheet Steel. Eachweldershall
demonstrateanabilityto producesatisfactorywelds usingaproceduresuchas shownintheSDIManual of Construction with Steel Deck, or asdescribedinANSI/AWSD1.3.
2.Aminimumvisible5/8inch (15mm)diameterarc puddleweldshallbeused. Weldmetalshallpenetrateall layersofdeckmaterial,and shallhavegoodfusionto thesupportingmembers.
3.Edgeribsofpanelsshallbe weldedateachsupport. Spaceadditionalweldsan averageof12inches(300mm) apartbutnotmorethan 18inches(460mm).
4.Whenused,filletweldsshallbeat least1-1/2inches(38mm)long.
5.Mechanicalfasteners,either powderactuated, pneumaticallydriven,or screws,shallbepermittedin lieuofweldingtofastendeck tosupportingframingif fastenersmeetallproject servicerequirements.When thefastenersarepowder actuatedorpneumatically driven,theloadvalueper fastenerusedtodeterminethe maximumfastenerspacingis basedonaminimumstructural supportthicknessofnotless than1/8inch(3mm)andon thefastenerprovidinga minimum5/16inch(8mm) diameterbearingsurface (fastenerheadsize).Whenthe structuralsupportthicknessis lessthan1/8inch(3mm), powderactuatedor pneumaticallydrivenfasteners shallnotbeused,butscrews areacceptable.
Commentary:Mechanicalfasteners(screws,powderorpneumaticallydrivenfasteners, etc.)arerecognizedasviable anchoringmethods,provided
thetypeandspacingofthe fastenersatisfiesthedesigncriteria.Documentationinthe formoftestdata,design calculations,ordesigncharts shouldbesubmittedbythe fastenermanufacturerasthebasisforobtainingapproval.
6.Fordeckunitswithspans greaterthan5feet(1.5m),side lapsandperimeteredgesof unitsbetweenspansupports shallbefastenedatintervals notexceeding36inches(1m) oncenter,usingoneofthe followingmethods: a.#10selfdrillingscrews b.Crimporbuttonpunch c.Arcpuddlewelds5/8inch (15mm)minimumvisible diameter,orminimum1inch (25mm)longfilletweld.
Commentary:Theabovesidelapspacingisaminimum.Serviceloadsordiaphragmdesignmayrequirecloserspacingorlargersidelapwelds.Goodmetaltometalcontactisnecessaryforagoodsidelapweld.Burnholes aretobeexpected.
B. AccessoryAttachment: 1.PourStopandGirderFillers: Pourstopsandgirderfillers shallbefastenedtosupporting structureinaccordancewith theSDIStandard Practice Details, and Attachment C2.
2.FloorDeckClosures: Columnclosures,cellclosures, girderclosuresandZclosures shallbefastenedtoprovide tightfittingclosuresatopen endsofribsandsidesof decking.Fastencellclosuresat changesofdirectionoffloor deckunitsunlessotherwise directed.
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AmericAn nAtionAl stAndArds institute/ steel deck instituteSTEEL DECKINSTITUTE
s ® C1.0 - 2006 Attachment C1
Composite Deck Construction Loading Diagrams
FIGURE 1Loading Diagrams
and Bending Moments
FIGURE 2Loading Diagrams
and Deflections
FIGURE 3Loading Diagrams
and Support Reactions
SimpleSpanCondition
DoubleSpanCondition
TripleSpanCondition
PW1
1
+M=.25Pl+0.125W11l2
l
+M=.125(W11+W2)l2
l
W2W1
1
PW1
+M=.20Pl+.094W1l2
l l
W1
+M=.094(W1+W2)l2
l l
W2
W1
–M=.117(W1+W2)l2
l l
W2
l
l
l
PW1
+M=.203Pl+.096W1l2
l l
W1
+M=.096(W1+W2)l2
l l
W2
W1
–M=.125(W1+W2)l2
l l
W2
SimpleSpanCondition
DoubleSpanCondition
TripleSpanCondition
SimpleSpanCondition
DoubleSpanCondition
TripleSpanCondition
l
l l
l l l
W1
W1
W1
.0130W1l4
EIΔ= (1728)
.0054W1l4
EIΔ= (1728)
.0069W1l4
EIΔ= (1728)
W1W2
W1W2
W1W2
l
l l
l l l
Pext Pext
Pext=.5(W1+W2)l
Pext Pext
Pext=.375(W1+W2)lPext
Pext=1.25(W1+W2)l
Pext Pext
Pext=.4(W1+W2)lPext
Pext=1.1(W1+W2)l
Pext
Notes for Figures 1, 2, and 3 LRFD Load Factors
P = 150poundconcentratedload................................ 1.4
I = in4/ft.-deckmomentofinertia
W1 = slabweight...................................................... 1.6
+deckweight...................................................1.2
W2 = 20poundspersquarefootconstructionload...............1.4
E = 29.5x106psi
l = clearspanlength(ft.)
W11 = 1.5xslabweight+deckweight<slabweight
+30+deckweight
Dimensionalcheckshowstheneedforthe1728factorwhencalculatingdeflectionsusingpoundinchunits.
Note:Inadditiontoananalysisofslabweightplusconstructionsurcharge,thedeckmustbeindependentlyinvestigatedforatotalconstructionloadof50psf.Thesteploadsinfigures1through3shallbeused.
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AmericAn nAtionAl stAndArds institute/ steel deck instituteSTEEL DECKINSTITUTE
s ® C1.0 - 2006 Attachment C2
Pour Stop Selection Table
0 1 2 3 4 5 6 7 8 9 10 11 12 20 20 20 20 18 18 16 14 12 12 12 10 10 20 20 20 18 18 16 16 14 12 12 12 10 10 20 20 20 18 18 16 16 14 12 12 12 10 10 20 20 18 18 16 16 14 14 12 12 10 10 10 20 20 18 18 16 16 14 14 12 12 10 10 20 18 18 16 16 14 14 12 12 12 10 10 20 18 18 16 16 14 14 12 12 12 10 10 20 18 16 16 14 14 12 12 12 12 10 10 18 18 16 16 14 14 12 12 12 10 10 10 18 18 16 14 14 12 12 12 12 10 10 18 16 16 14 14 12 12 12 12 10 10 18 16 14 14 14 12 12 12 10 10 10 18 16 14 14 12 12 12 12 10 10 10 16 16 14 14 12 12 12 10 10 10 16 14 14 12 12 12 12 10 10 10 16 14 14 12 12 12 10 10 10 10 14 14 12 12 12 12 10 10 10 14 14 12 12 12 10 10 10 10 14 12 12 12 12 10 10 10 14 12 12 12 12 10 10 10 14 12 12 12 10 10 10 12 12 12 12 10 10 10 12 12 12 10 10 10 12 12 12 10 10 10 12 12 10 10 10 10 12 12 10 10 10 12 12 10 10 10 12 10 10 10 12 10 10 10 12 10 10 10 10 10 10 10 10 10
ovERhANG (INChES)
4.00 4.25 4.50 4.75 5.00 5.25 5.50 5.75 6.00 6.25 6.50 6.75 7.00 7.25 7.50 7.75 8.00 8.25 8.50 8.75 9.00 9.25 9.50 9.75 10.00 10.25 10.50 10.75 11.00 11.25 11.50 11.75 12.00
SLAB
(INChES) PoUR SToP TyPES
DEPTh
NoTES: This Selection Chart is based on following criteria:1. Normalweightconcrete(150PCF).2. Horizontalandverticaldeflectionislimitedto¼”maximumforconcretedeadload.3. Designstressislimitedto20KSIforconcretedeadloadtemporarilyincreasedbyone-thirdfortheconstructionliveloadof20PSF.4. PourStopSelectionChartdoesnotconsidertheeffectoftheperformance,deflection,orrotationofthepourstopsupportwhichmay includeboththesupportingcompositedeckand/ortheframe.5. Verticallegreturnlipisrecommendedforalltypes(gages).
TYPES DESIGNTHICKNESS
0.03580.04740.05980.07470.10460.1345
201816141210
1”(25mm)filletwelds@12”o.c. pourstop slab
depth
2”(50mm)min.
overhang
seenote5½”m
in.
10
AmericAn nAtionAl stAndArds institute/ steel deck instituteSTEEL DECKINSTITUTE
s ® C1.0 - 2006 Attachment C3
SI Units Conversion Tables
LENGTh
AREA
MASS
FoRCE
PRESSURE
SECTIoNMoDULUS
MoMENT oFINERTIA
intommfttommfttom
in2tomm2
ft2tom2
lbtokg2000lbto1000kg
lb/fttokg/mlb/ft3tokg/m3
lb/yd3tokg/m3
lbtoNkiptokN
lb/intoN/mlb/fttoN/m
kip/fttokN/mpsftokN/m2
lb/in2tokPalb/ft2tokPa
kip/in2toMPa
in3tomm3
in3/fttomm3/m
in4tomm4
in4/fttomm4/m
25.4(exact)304.8(exact)
0.3048(exact)
645.16(exact)0.092903
0.4535920.9071851.4881616.0185
0.593276
4.448224.44822175.12714.593914.593947.880
6.894760.047886.89476
16387.153763.5
4162311365587
To ChANGE MULTIPLy By
11
AmericAn nAtionAl stAndArds institute/ steel deck instituteSTEEL DECKINSTITUTE
s ® C1.0 - 2006 Attachment C4
Strength and Serviceability Determination of Composite Deck-SlabUnlesscompositedeck-slabsaredesignedforcontinuity,theloadaffectsareassumedtoactonsimplespans.
C4.1StrengthforBending Thissectionisused todeterminethebending strengthofthecomposite deck-slab.
A. SDIMethod-WithNoShear StudsonBeams Thismethodisusedifthereare noshearstudspresentonthe beamsupportingthe compositesteeldeck.
Theresistingmoment,Mno
,of thecompositesectionis determinedbasedonacracked sectionanalysis.Referto attachmentC5forcalculation ofthetransformedsection properties.
where Fy = yieldstressofsteel deck≤60ksi h = slabdepth Icr = crackedsection momentofinertia Mno= nominalresistingmoment Ycc = distancefromtopofslab toneutralaxisofcracked section φ = 0.85andistheresistance factor
1)Limitations The“SDIMethod”shallbe limitedtogalvanizedortopside uncoatedsteeldeckswith embossments.Theembossment patternsshallbetypicalofthe manufacturedsteeldeckwith thedepthoftheembossment notlessthan90%ofthetested embossmentdepth.Theweb
angle,,shallbelimitedto valuesbetween55°and90°and thewebsshallhaveno reentrantbendsintheirflat width.Thesteelsectiondepth, d
d,islimitedto3in.(75mm).
Theconcretedesign compressivestrengthsshallbe between2500psi(17MPa)and 6000psi(40MPa).Theminimum concretethicknessabovethesteel deckshallbe2inches(50mm).
Theusableslabcapacityis limitedtodeckswiththickness 0.0474inches(1.20mm)unless sufficienttestdataisavailableto supporttheuseofthemethod withdeckofgreaterthickness.
2)ContinuityOverSupports Incontinuousslabs,those sectionssubjectedtonegative momentsshallbedesignedas conventionallyreinforced concreteslabs.Incomposite slabs,momentsandshearsshall becalculatedbyananalysisor,if applicable,bythecoefficientsof Chapter8ofACIBuilding Code Requirements for Reinforced Concrete,ACI318.
3)AllowableStressDesign Allowablestressdesign(ASD) isacceptableasanalternate designmethod.SeetheSDI Composite Deck Design Handbook.
B. SDIMethod-WithShear StudsonBeams Thismethodistobeusedif thereareshearstudspresent onthebeamsupportingthe compositesteeldeckin sufficientquantitytodevelop theultimatecapacityofthe sectioninbending,oriftestson aparticulardeckprofile haveshownthatthedeckis capableofdevelopingthefull
ultimatemomentwithoutshear studs.
where As = steeldeckareaperunit widthofsteeldeck
a = = developeddepth ofconcreteinthe compressionzone b = unitwidth d = distancefromthetopoftheslab tothecentroidofthesteeldeck Fy = steelyieldstrength,notto exceed60ksi(415MPa) Mnf = nominal(ultimate)moment capacitywithstudsonbeam φ= 0.85andistheresistancefactor
Thismethodislimitedto constructionswherethenumber ofshearstudspresentequalsor exceedsN
s,theminimumnumber
ofshearstudsperfootofdeck widthtodevelopthefullcross sectionofthesteeldeck.
where Abf = deckbottomflangeareaper unitwidthofsteeldeck
Asc = cross-sectionalareaofstud shearconnector,in2(mm2)1/2” and3/4”diameterstudsare acceptable
Awebs=deckwebareaperunitwidth ofsteeldeck
f'c = concretestrength,ksi(MPa)
Ec = modulusofelasticityof concrete=
Qn = = nominalstrengthofone studshearconnectorin solidconcrete
φMno=φFy Icr
h-ycc
=φScFy
φMnf=φAsFy(d-a/2)
AsFy
0.85f'cb
Ns=Fy
Qn
Awebs
2As– –Abf ,studs/unitwidth
w1.5,ksi(0.043w1.5,MPa)c f'c c f'c
0.5AscEc<0.75AscFuf'c
q q
q
1�
AmericAn nAtionAl stAndArds institute/ steel deck instituteSTEEL DECKINSTITUTE
s ® C1.0 - 2006 Attachment C4(continued)
Thevalue,Ns,istobeinstalled alongeachbeam.Atbuttedend laps,studsshallbestaggeredto arrestbothendsofthedeckat thecommonjoint.Atperimeter conditionsoropenings(where slabsarediscontinuous)all studsmustengagethedeckend. Thevalue,Q
n,issubjectto
reductionwhenconsidering compositebeamactionand thestudisinstalledthrough deck.Reductiondoesnotapply tothedeterminationofNs.
Thefollowingistobeusedwhen theshearstudsarepresenton thebeamsupportingthe compositesteeldeck,butare notpresentinsufficientquantity todeveloptheultimatecapacity ofthesectioninbending.
UseφMnpforthefactored resistanceindesign.
where MnoisdeterminedfromSectionC4.1.A MnfasdeterminedfromSectionC4.1.B
Mnp= useablenominalmoment capacityatstuddensity=N's
N's = thenumberofshearstuds actuallypresentalongthe beamperunitwidthofsteel deck–1/2”and3/4”diameter studsareacceptable
N'sisdeterminedfromSectionC4.1.B φ = 0.85andistheresistancefactor
C.AlternateMethods Otherrationalmethodsfor establishingcompositeslab strengthcanbeusedifthe pertinentparameters contributingtocomposite slabstrength(includingdeck crosssection;steel
thickness;concreteweight, strength,andtype;shear transferdevices;methodof loading;etc.)areconsidered. Theseanalysescaninclude nonlinearrelationshipsbetween variousparameters.Sufficient testsshallbemadetoestablish themethod-testvariability.
C4.2StrengthforShear Thissectionisusedtodetermine theshearstrengthofthe compositedeck-slab.
where Vc = 2βcAc,shearresistanceof concreteperunitwidth VD = shearstrengthofthesteeldeck sectionperunitwidth calculatedperAISI
Ac = concreteareaavailableto resistshear,seeFigureC1
βc = 1.0ifconcretedensityexceeds 130lbs/ft3,0.75otherwise
C4.3Deflection Thedeflectionofthecomposite slabshallnotexceedspan/360 undersuperimposedload.The deflectioncanbepredictedusing theaverageofthecrackedand uncrackedmomentofinertiaas determinedfromthetransformed sectionmethodofanalysis.
Mnp=Mno+(Mnf–Mno)<≤MnfN'sNs
f'cVn=Vc+VD≤4Ac
f'c
Figure C
q
q
1�
AmericAn nAtionAl stAndArds institute/ steel deck instituteSTEEL DECKINSTITUTE
s ® C1.0 - 2006 Attachment C5
Ifycc>hcuseycc=hc.
ThecrackedmomentofinertiaIcis
where
Isf isthemomentofinertiaofthefull(unreduced) steeldeckperunitslabwidth.
C5.3 MomentofInertiaofUncrackedSection Fortheuncrackedmomentofinertia
Theuncrackedmomentofinertiais
C5.4 MomentofInertiaofCompositeSection Themomentofinertiaofcompositesectionconsidered effectivefordeflectivecomputationsisgivenby
C5.1TransformedCompositeNeutralAxis Thedistanceyccfromtheextremecompressionfiberof theconcretetotheneutralaxisofthetransformed compositesectionshallbedeterminedfrom FigureC5.1andEquationC5-1.
Note: 1. Sectionshowsnon-cellulardeck.Sectionshallbe eithercellular,ablendofcellularandnon-cellular deck,ornon-cellulardeck
2. C.G.S.=centroidalaxisoffullcrosssectionofsteel deck
3. Cs=pitch
4. N.A.=neutralaxisoftransformedcomposite section
5. Wr=averageribwidth
C5.2 MomentofInertiaofCrackedSection Whenyccisequaltoorlessthanthedepthofconcrete,hc, abovethetopofsteeldeck,thatis,ycc<≤hc,then
where
ρ = As = areaofsteeldeckperunitslabwidth
b = unitslabwidth(12inchesinimperialunits)
d = distancefromtopofconcretetocentroidofsteeldeck
n = modularratio=
Figure C5.1-Composite Section
ycc=d
2ρn+(ρn)2–ρn
Asbd
Es
Ec
ycc=
bCs
0.5bh2+nAsd+Wrdd(h–0.5dd)c
bCs
bhc+nAs+Wrdd
Iu= +(ycc–0.5hc)2+Isf+Asycs++(h–ycc–0.5dd)2bhc
12n
3 bhc
n2 Wrbdd
nCs
dd
12
2
ycs=d–ycc(UseyccfromEquationC5-3.)
(C5-1)
f'c
f'c
Es = 29500ksi
Ec = γ1.5 ksi
γ = concretedensity,lbs/ft3
= concretestrength,ksi
ycs=d–ycc(UseyccfromEquationC5-1.)
Icr=ycc+Asycs+Isf3 2b
3n(C5-2)
(C5-3)
(C5.4)
(C5.4)(Transformedtosteel)Id=Iu+Icr
2
Section Properties of Composite Deck - Slabs
q
q
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