prof. samit raychaudhari , dept ofce (co pi) dr. kk … -5.pdf · eucenter report, 2016 precast...

Development of draft protocol for testing of structural components and systems for use in schemes under ‘Housing for all’ project of the Government of India

Prof. Sudhir Misra, Dept of CE (PI)Prof. Samit Raychaudhari , Dept of CE (Co‐PI)

Dr. KK Bajpai, Dept of CE (Co‐PI)

1MHUPA- Protocol for testing, HFA23/11/2016

Department of Institute of Technology Kanpur, KANPUR

Systemleveltestingmeansthatthetestingisdoneforthecompleteassemblyortheproductlikecustomeratthetoplevellookingfortheharmonyamongdifferentcomponents

Componentleveltesting(orUnittesting)isfocussedonthefunctionalityofaparticularpartwithoutconsideringmuchonhowitworkswithothers.

Systemvs.ComponentLevelTesting

System MasonryStructure RCStructure SteelStructure TimberStructure PrecastconcreteStructure

Component Slab WallPanel beam Column Beam‐columnconnection

ForSystems&Components:Teststandardsforperformanceofdifferentconstructionpracticese.g.masonrywalls,Precastslabsandbeams,RCBeam‐columnsetc.

• Subjectedtoin‐planeandout‐of‐planebending• Cyclicloading• WindLoading

Typesofcomponentinclude‐Cast‐in‐situcomponentPrecastorPrefabricatedcomponent

Protocolsfortestingofstructuralcomponentsandsystems

Cast‐in‐Situ Precast

Cast‐in‐situvs.Precast• precastconcretestructuresareabletoresisttoearthquakeloadingasreliablyasanalogouscast‐inplaceones.

• Energydissipationinprefabricatedcolumnsoccurswithinavolumeofmaterialwhichisequaltothattopandbottomedgesectionsofcast‐in‐placecolumnsdesignedtowithstandthesamebaseshearforce.

Ferraraetal.2004

Precast concrete structures are traditionally designed as moment resistingframes with plastic hinges occurring at the column base, and beams hingedto the columns.

Replacement with Precast system gives the advantage of designingcontinuous beams with a reduced beam depth, or with an increase of eitherspan length or carried load.

Precastbeam‐columnconnection

ExperimentalSetUpforJointTesting

CyclicLoadingProtocol InstrumentationSet‐UpEUCENTERReport,2016


Inputmotion,scaledtoPGAof1g.

ModifiedResponseSpectrabyEC8soilFactorB

(Negro et al. 2013)


PseudodynamicTesting

A.Shearwallsandhingedbeam–columnjoints

B.Hingedbeam–columnjoints

• Thepresenceoftwostiffprecastwallunitsinprototype1wasquiteeffectiveinlimitingthemaximuminter‐storeydriftratiosforboththeserviceabilityandultimatelimitstates.

(T=0.3Sec)

Theseismicresponseofprototype2washighlyinfluencedbytheeffectsofhighermodes. Thisresultsintolargeforcedemandsin

theconnectionsinthenonlinearregime. The1%driftlimitationwasexceeded,

precastsystemwithhingedbeam‐tocolumnjointswascharacterizedbyexcessivedeformability.

Nosignificantdamageinitsstructuralmembers.(T=1.09Sec)

(Negro et al. 2013)


C.Hingedbeam–columnatthe1stand2ndfloorandemulativeatthe3rd

D.Emulativebeam–columnjoints

After the seismic test results of prototype 3,the concept of emulative beam–column jointsat the top floor only was not much effective.• The effect of higher modes is also

significant.(T=1.08 Sec)

Finally, when activated at all the floors, theproposed connection system is quite effectiveas a means of implementing dry precast(quasi) emulative moment‐resisting frames. Dense flexural cracking at the base of the

ground floor columns, but again withoutconsiderable damage.(T=0.66 Sec)

(Negro et al. 2013)


Category1:connectionsisthatbetweenadjacentfloororroofelements.Category2:connectionsbetweenfloororroofpanelsandsupportingbeams.Category3:connectionsbetweencolumnsandbeams.Category4:connectionsusedtojoincolumnsandfoundationsCategory5:connectionsbetweenwall(orcladdingpanels)andslabelements.

(Bournas et al. 2013)


Behaviorofconnection


(a) Seatingofasecondarybeamonthecolumncapital.

(b) Acentralbeam–columnjoint.(c) Detailofapinnedbeam–columnjoint

connection.(d) Specialdowelswithincreased

diameteratthecriticalsection.

PinnedJointConnection:• It is able to transfer shear and axial

forces both for the gravity and seismicforces and possible uplifting forces dueto overturning.

• Bydefinition,theycannottransfermomentandtorsion,althoughinrealitytheydotransferasmallamountofbendingmoment.

• Thehorizontalconnectionbetweenthebeamandthecolumnwasestablishedbymeansoftwoverticalsteeldowelswhichwereprotrudingfromthecolumnintospecialbeamsleeves.



(a) Connectorusedtorealizedryemulativebeam–columnjoints.

(b) Testset‐upadoptedtoassessthetensilecapacityoftheconnectionsystem.

• The second beam–column connectiontype, which emulates fixed beam–columnjoints.

• In order to provide continuity to thelongitudinal reinforcement crossing thejoint, an innovative ductile connectionsystem, embedded in the precastelements, was activated.

• This connection system comprises foursteel rebars slightly enlarged at theirends, two thick steel plates and a bolt thatconnects the two steel plates

(c)Typicalloadversusdisplacementcurveofthebareconnectionsystem.(d)Ductileruptureofthelongitudinalrebars.


B.Hingedbeam–columnjoints

• Tofulfillthedemandoflargeforcesintheconnections,ifdesignerdoesnotincludeshearwallsintheseflexiblesystems,thelargemagnificationofstorey forces(determiningthecapacitydesignofconnections)shouldbeconsidered.

• Thebeam–columnjointslipwasreduceddramaticallyinthecaseofmomentresistingjoints,thatis3.5timeslowerthanitscounterpartwithhingedbeam‐to‐columnsjoints.

• Theparticipationofthebeamsintheframebehaviorofprototype4washigher,however;theemulativebeam–columnjointresponseinprototype4wasquitedifferentfromarigidjoint.Theexecutionofthismechanicalconnectionhasnoqualitycontrolorcertificationforthetimebeing.Thisresultedintoasemi‐rigidbeam–columnjointwithasymmetric(inthetwodirectionsofloading)andunequal(betweenbeamsandcolumns)rotations. (Bournas et al. 2013)


3storey prototypebuildingstructure Instrumentationandsetup: LVDT,StrainGauge,Hydraulicjack,Reactionframe

CompleteBuildingSystem ScaledBeam‐ColumnJoint


(Vidjeapriya et al.)

Experimentalsetupandmodels 3experimentalmodels• Monolithic(cast‐in‐situ)(ML)• Precastmemberswithsinglestiffener(PC‐SS)• Precastmemberswithdoublestiffener(PC‐DS)

Reversecyclicdisplacementcontrolled

loading



SampleResultsPrecastbeam‐columnconnection


PerformanceEvaluation(Cast‐in‐situvs.Precast)• Columndamageisminimalinprecastsystems• Doublestiffenerprecastsystememulatesperformanceofcastinsitumonolithicsectionconsideringstrengthanddamping

• PC‐DShasbetterductilitythanthatofSpecimenPC‐SSandMLspecimen

CracksinPCjointCracksinMLjoint



PrecastDiaphragmwallpanelAprecastwallpanelsystemcanbecomprisedof:

Flatorcurvedpanels(solid,hollow‐core,orinsulated) Windowormullionpanels Ribbedpanels Double‐tee

Excessivegapopeningbetweenpanels

Shearslip

Undesirabledeformationsalonghorizontaljoints

WallandHorizontalLoading

TypicalWallDeformation:• DuetoShear• DuetoFlexure

EUCENTERReport,2016

PrecastDiaphragmwallpanelHorizontalloaddeformationScenarios:

CantileverWallCoupledWall

RockingWall

• Cantileverwallsresisttheoverturningmomentresultingfromthelateralforcesbybending.

• Coupledwallsresisttheoverturningmomentnotonlybybendingoftheindividualwallsbutalsothroughanaxialforcecouple.

• Rockingwallsresistoverturningmomentatthebaseofthewallsthroughthecouplearisingfromtheeccentricitybetweentheactinggravityloadandthereactionatthewall‐foundationinterface.

EUCENTERReport,2016

PrecastDiaphragmwallpanel

Horizontalloadcarryingmechanism

• 3storey Precastboxstructure.• SymmetricStructuretoavoidthetwist.• Instrumentation:LVDT,StrainGauge,Potentiometer,Accelerometer.

• ShakeTableMovement:WhiteNoiseofdifferentintensity.

Leeetal.1996


Results:• ModelwastakeninNon‐linearrangeduringthe0.8gwithrocking

motion.• CracksappearedinHorizontaljointsin0.12gandwerepropagatedinthe

horizontaldirection.• In1.4g,thejointboxwascrushedinHorizontaljointswithoutanycrack

inwallpanelsandverticaljoints.

Leeetal.1996



In‐planeloadingsetups

Instrumentation HydraulicJack LVDT Straingauges Loadcell Shearactuator

Thetestthusprovidesanestimateofaverage connectoryield,peakstrength,andthedeformationcapacity.

Monotonicshearprotocolconsistsofthreecyclesto0.01inch

Out‐of‐planemonotonicsheartests

Instrumentation HydraulicJack LVDT Straingauges Loadcell


Forcecontrolled MonotonicIn‐planeShear CyclicIn‐planeShear MonotonicIn‐planeTension CyclicIn‐planeTensionandCompression

MonotonicIn‐planeShearwithProportionalTension

DisplacementcontrolledMonotonicandCyclicShearDeformationwithaTargetAxialLoadof0kips;

CyclicShearDeformationwithaTargetAxialLoadof10kips

Inplaneloadingprotocols

Forcecontrolled

Displacementcontrolled


performanceCategorizationasperASCE/SEI41‐06SeismicRehabilitation

Eachconnectionclassificationasdeformation‐controlled(ductile)orforcecontrolled(non‐ductile)

AssessmentwithBack‐bonecurves


Thepurposeofthetest‐Thesystemcanhandleaboveandbeyondthetypicaldesignloadsweworkwith,whileofferingadvantagesoverothersystems– advantagessuchaslighterweightandinsulation

PrecastBeams

Precast.org

loadtestingofnewprecastconcretefloorplanksystem

DeadloadtestonPre‐stressedPrecastBeams‐fordifferentmagnitudeofstaticloads

Precast.org

PrecastBeams

deflectionatmid‐spanofplank Crackingatmid‐span

StaticDeflectionsweremeasuredanddeadloadonthecomponentissimulated.• Deflectionismeasuredimmediatelyafterloading.• Deflectionismeasured136hoursafterloading.• Crackpropagationismonitoredfordifferentdeadloads

Precast.org

PrecastBeams

PrecastSlabPrecast slabs are cast in a factory environment and include thefollowing options:

Hollow core Double Tee (TT) Solid Biaxial void slabs

PrecastSlabDepending on the position of slab following slab panels areconsidered for testing

Externaldiaphragm

Intermediatediaphragmsupport

Diaphragmpaneltopanelinteraction

Externaldiaphragm

Internaldiaphragmconnection

(Fleischman et al.)

PrecastSlabLoadingprotocols

Instrumentation Shearactuator LVDT Straingauges

(Fleischman et al.)

ReinforcedConcreteBeam‐ColumnJoint Since their constituent materials have limited strengths, the jointshave limited force carrying capacity.

Repairing damaged joints is difficult, and so damage must beavoided.

Thus, beam‐column joints must be designed to resist earthquakeeffects.

Castingspecimen

Castingspecimendetails

ReinforcedConcreteBeam‐ColumnJoint

The displacement at the ends of the beams wasincreased by steps from 0.25 % up to a drift of 1.0 %per drift amplitude, then two cycles for each driftamplitude greater than 1 %

A total of twelve displacement cycles were applied upto 5 % drift cycle

Instrumentation HydraulicJack LVDT LaserSensor Straingauges Loadcell

ReinforcedConcreteBeam‐ColumnJoint

Loadingprotocols

ReinforcedConcreteBeam‐ColumnJoint PerformanceofspecimenCrackpropagation

RecordedStrain

SteelBeam‐ColumnJoint Steel beam‐column joints are vulnerable to brittle fracture duringseismic events

There are higher chances of formation of plastic hinges near thebeam‐column joint during nonlinear response of structure

Thus, beam‐column joints must be designed to resist earthquakeeffects.

SteelBeam‐ColumnJointPossibleTestSetups

SampleTestSetup

Instrumentation HydraulicJack LVDT Straingauges Loadcell

SteelBeam‐ColumnJoint

SteelBeam‐ColumnJointLoadingProtocol InitialStage

DeformedStage

Realisticearthquaketypeloadingforprototypicalstructuralsystems

IITKPseudoDynamicsTestingFacility

IITKPseudoDynamicsTestingFacility• Equationsof

motionsaresolvedon‐linefordisplacementstobeappliedinrealtimewhileupdatingthesystemparametersfromon‐linemeasurementsofforcesanddisplacements.

• Effectofinertiaforceisaccountedforinapproximatesenseandstrainrateeffectsarenotconsideredastestiscarriedoutatslowrate.PseudoDynamic(PsD)Test

IITKPseudoDynamicsTestingFacility

• Synthesisofnumericalmodeling andexperimentaltesting.

• Requireadequatesimulationofboundaryconditionsattheinterface

HybridPsD usingSubstructures

Characteristics:TableSize 1.2mx1.8mWeightofTable 8kNMaximumPayload 40kNMaximumDisplacement 75mmMaximumVelocity 1.5m/sMaximumAcceleration 5gFrequencyRange upto 50Hz

IITKShakeTableTestingFacility

• Forsmallscaledynamicmodeltestingi.e.componenttesting

ISMB600sectionsforallmembersHeight:4.2m,Lateralload:4000kN andOverturningmomentcapacity:6000kNm

IITKCyclicTestingFacility

ReactionFrame

ForWallTestingor

FrameTesting(SmallScale)

IITKWindTunnelFacility

TallChimney TallBuilding

CivilEngineeringApplicationofWindTunnel

References• Naito, Clay, and Ruirui Ren. "Evaluation Methodology for Precast Concrete Diaphragm

Connectors Based on Structural Testing." (2008).• Fleischman, Robert B., et al. "Development of a seismic design methodology for

precast diaphragms." (2004).• Ahmed, Saddam M., and Umarani Gunasekaran. "Testing and evaluation of reinforced

concrete beam‐column‐slab joint." Građevinar 66.01. (2014): 21‐36.• Lee, Cheol‐Ho, et al. "Cyclic seismic testing of steel moment connections reinforced

with welded straight haunch." Engineering Structures 25.14 (2003): 1743‐1753.• “SAC ‐ Nonlinear Structural Dynamics And Control Research” by SACJ Venture• Lee, HL., et al. “Shake Table Test of Precast Concrete Wall Structure”. 11th World

conference on Earthquake Engineering, Elsevier Science, 1996.• Ferrara, L., et al. "Precast vs. cast‐in‐situ reinforced concrete industrial buildings

under earthquake loading: an assessment via pseudo‐dynamic tests." Proceedings ofthe 13thWCEE. 2004.

• Northeast Precast company blogs‐ By Peter Gorgas (Precast.org)• “Numerical and experimental evaluation of the seismic response of precast wall

connections”, EUCENTER Report, 2016• Negro, Paolo, Dionysios A. Bournas, and Francisco J. Molina. "Pseudodynamic tests on

a full‐scale 3‐storey precast concrete building: global response." EngineeringStructures 57 (2013): 594‐608.

• Bournas, Dionysios A., Paolo Negro, and Francisco J. Molina. "Pseudodynamic tests ona full‐scale 3‐storey precast concrete building: behavior of the mechanicalconnections and floor diaphragms." Engineering Structures 57 (2013): 609‐627.

ThankYou

prof. samit raychaudhari , dept ofce (co pi) dr. kk … -5.pdf · eucenter report, 2016 precast...

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