砌体结构MasonryStructure40课件讲解

砌体结构

MasonryStructureWhatismasonrystructure?Whatarethematerialsformasonrystructure?Whatisthefeatureformasonrystructurecomparedwithotherstructuraltypes(concretestructure,steelstructure)?Question?

Structureistheskeletontobearforceforthebuilding,canbedividedintothefollowingmaintypes

accordingtothebuildingmaterials

:ConcretestructureSteelstructureTimberstructureMembranestructure

MasonrystructureClassificationforStructures

ConcretestructureConcreteStructureThemainclassroombuilding,HITTheTaiheHall,TheFormerImperialPalace(the

ForbiddenCity,

Beijing)TimberStructureTimberStructureHeilongjiangTVTower(DragonTower,336m)SteelStructureTherevolvingrestaurant(186m)TheNationalStadium(Bird’sNest)330m*220m*69.2m

SteelStructureTheBigWave(Hiroshima,Japan)TheGameCenter(Shenzhen,China)MembraneStructureTensilemembrane

structure

Pneumaticmembrane

structureTheBeijingNationalAquaticsCenter(TheWaterCube)TensilemembranestructureTheGreatwall,ChinaMasonryStructurePyramid,EgyptSt.SophiaCathedral,HarbinMasonryStructureTextandReferenceDesignofReinforcedMasonryStructures

byNarendraTalyCodeForDesignofMasonryStructure,China(inChinese,inEnglish)UpdateknowledgeMasonryStructuresBehaviorandDesignbyRobertG.DrysdaleandAhmadA.HamidChapter1:Preface

ContentsDefinitionandclassificationofmasonryHistoryandcurrentsituationofmasonryDevelopmentofmasonrystructuresCharacteristicsofmasonrystructureObjectiveandrequirementFiredclaybrick(2)Firedperforatedbrick(1)Firedcommonbrick

Rawmaterials：clayConcretehollowblock

Rawmaterials：fineaggregateconcreteMortariscomposedofcement,lime,sandorotherspecializedadditive;Bondmasonryunitstogether;Mortar1.1DefinitionandclassificationofmasonrystructureDefinitionMasonryistypicallyconstructedusingmanufacturedblockorbrick,orstoneandmixedmortar.Masonryisnormallyusedforcomponents(columnorwall)subjectedtocompressiveloading.Apieceofbrick(block)—Masonry

UnitBedjointMasonryunit:apieceof

brick,blockorstone;Bedjoint:Thehorizontallayerofmortaronwhichamasonryunitislaid.1.1Definitionandclassificationofmasonrystructure2.ClassificationUnit：1)Brickmasonry2)Blockmasonry3)StonemasonryBlockMasonryBrickMasonryStoneMasonry1.1Definitionandclassificationofmasonrystructure2.ClassificationUn-reinforcedMasonryWallRinforcement：Un-reinforcedmasonry(Plainmasonry)；ReinforcedmasonryDrawbackforplainMasonry：Weaktensileandshearstrength；Cannotbeusedforbeams,slabs;Unsuitableforcolumnssubjectedeccentricloadthatproducetensilestressesinthem.1.1Definitionandclassificationofmasonrystructure2.ClassificationReinforcedGroutedConcreteBlockMasonryStructureToovercomethedisadvantage,un-reinforcedmasonrystructuresneedtobestrengthenedwithreinforcingmaterialssuchassteelbars,whichgreatlyenhanceitstensile,shearaswellascompressivestrength.VerticalsteelHorizontalsteelPourtheconcreteintothehollowofconcreteblock.1.2HistoryandcurrentsituationofmasonryPyramid(Egypt)Taperedside→stableshapeParthenon(Athens)ColumnssupportedstonebeamColosseum(Rome)MasonryarchPantheon(Rome)CircleshapeNotredamecathedral(Paris)Lateralvaults(parallel)Thehistoryofmasonryconstructioncanbeconsideredasthebeginningofthehistoryofcivilengineering.ForeignancientexamplesChineseancientexamples1.2HistoryandcurrentsituationofmasonryZhaozhoubridge

◆

wasbuilt1400yearsago;

◆

1largearch+4smallarch;

◆

Lightenweight;sluicing;

◆51mlong,9.6mwide.BeamlesshallTheGreatWall

◆HistoricalrecordstracetheconstructionoftheoriginoftheGreatWalltodefensivefortificationbacktotheyear656B.C.;

◆ThemostextensivereinforcementsandrenovationswerecarriedoutintheMingDynasty(1368~1644)withbricksandrocks.

ForeignmodernexamplesRoyalhospitalinLiverpool,British11storiesExcaliburHotelinLasVegas,USA28stories1.2HistoryandcurrentsituationofmasonryChinesemodernexamplesShanghai，18stories，1997Harbin，18stories，1999Zhuzhou，19stories，20071.2HistoryandcurrentsituationofmasonryChinesemodernexamplesDaqing，12~17stories，20051.2HistoryandcurrentsituationofmasonryAdvantages1）Usinglocalmaterials,lowcost;2）Gooddurability，goodfireproofing;3）Constructionlessinfluencedbyambientclimateandconstructioncondition;4）Goodsound/thermalinsulation——suitableforliving.1.3Characteristicsofmasonrystructure1.3CharacteristicsofmasonryDisadvantages1）Lowstrength,largeselfweight;2）Laborintensityishigh;lowdegreeofmechanization3）Lowtensileandshearstrength→pooraseismicpropertyforun-reinforedmasonry;4）Therawmaterialsofbrickisclay;theexploitationofclayinfluencesagriculturalindustry;productionofclaybrickisakindofharmforenvironmentalprotection.1.SustainabledevelopmentrequirementPerforatedfiredbricks;Perforatedconcreteblocks;Useofindustrialwaste(e.g.coalslag).1.4DevelopmentofmasonrystructuresPerforatedconcreteblock

PerforatedfiredbrickConcretebrickwithindustrialwaste

ReplacefiredsolidclaybrickReduceclayconsumption;Helpfulforlandresourceandenvironmentalprotection

2.Highstrength,lightweight,highperformancematerialsReinforcedmasonry;Highstrengthandlightweightconcreteblock;Specialmortar;Exteriorwallwiththermalinsulation.1.4DevelopmentofmasonrystructuresSpecialmortarforconcretehollowblockConcreteblockforexteriorwallwithselfthermalinsulation3.NewtechnologyandnewstructuresystemPre-stressedmasonry1.4DevelopmentofmasonrystructuresPre-

stressedreinforcementbarsThepre-stressedblockmasonrywallsubjectedtohorizontalloadHowtopre-stressformasonrywall?

－Vibrationisolationsystem→

reducetheseismiceffectonmasonrystructure;－Retrofittingtechnologytomitigateseismicaction.

1.4DevelopmentofmasonrystructuresTestofmasonrywallwithvibrationisolationsystem－Vibrationisolationsystem→

reducetheseismiceffectonmasonrystructure;－Retrofittingtechnologytomitigateseismicaction.

1.4Developmentofmasonrystructures

RetrofittingusingFRP(Fiberglass-ReinforcedPlastics)ThevibrationtestofmasonrybuildingwithFRPreinforcing

FRP(Fiberglass-ReinforcedPlastics)Homework:

1.Pleasedrawastatementaboutthemasonrystructureinyourcountryaccordingtoyourownunderstandingorinvestigation,includingthemasonrymaterial,typicalmasonrystructure.2.Pleasesearchanddownload2~3photographs(pictures)ofmasonrystructurebuiltinyourcountryfrominternet.PrintyourhomeworkoutincopypaperA4;SubmitthehomeworkonnestMonday.

Chapter2

MasonrymaterialsandmechanicalperformanceContents2.1Masonrymaterials2.3MechanicalperformanceofmasonrymaterialsPrefaceTypeofmasonrystructures:

Steelmesh-reinforcedmasonrycolumnsorwalls;CompositewallsofbrickmasonrywithreinforcedconcretecolumnsReinforcedconcreteblockmasonrywallsorcolumns.1.Un-reinforcedmasonrystructure:BrickmasonrystructureBlockmasonrystructure

Stonemasonrystructure2.Reinforcedmasonrystructure：Materialsofmasonrystructures2.1MasonrymaterialsMasonryunitFiredclaybrick;Concretehollowblock;MortarCommonmortar;MortarforconcreteblockmasonrySteelreinforcementConcreteCommonconcreteConcretegroutforconcretesmallhollowblock2.1.1Masonryunit1.Firedclaybrick(1)FiredcommonbrickRawmaterials：claySizeofthestandardbrick：240×115×53mmThicknessofthemasonrywalls：115、240、370、490、620…mm(2)Firedperforatedbrick

Rawmaterialsisthesameasfiredcommonbrickandtheholerateisnotlessthan25%.Saveclayandmortar,increasetheworkingefficiency;Savethecostofthewall,decreasetheweight.2.ConcretesmallhollowblockRawmaterials：fineaggregateconcretesize：390mmx190mmx190mm;190mmx190mmx190mm;290x190mmx190mm;Hollowrate：45%～50%TypeofconcretehollowblockThehorizontalreinforcementislaidinthegrooveTypeofhollowblock1.Effectofmortar：Mortariscomposedofcement,lime,sandorotherspecializedadditive;Bondmasonryunitstogether;Resistwaterandairpenetrationthroughthegapbetweenmasonryunits;Influencecompressive,shear,tensile,andflexuralstrengthsofmasonryassemblage;Forreinforcedmasonry,bondtoreinforcementoranchors,sothattheyperformintegrallywiththemasonryunits.2.1.2Mortar2.1.2Mortar2.TypeofmortarCementmortar

Cement,sandandwater

Mixedmortar

Cement,lime,sandandwater

SpecialmortarCement,lime,sand,waterandsomespecializedadditivetoprovidebetter

flexibilityandmoistureretention;Usually,specialmortarisusedforconcretehollowblock.2.1.3Grout(Concrete)DefinitionofthegroutGroutisamixtureofcementitiousmaterials(limeandPortlandcement),fineaggregateandsufficientwatertoachieverequiredfluiditysothatitcanbeeasilypouredinthehollowofthemasonryblock.Whenpoured,thegroutshouldbecompletelyencasethereinforcementsteel.Pourthegroutintothehollowofconcreteblock2.1.3Grout(concrete)FunctionsofthegroutGrouthelpsconnectvariousmasonryunitstoacttogether;Groutisusedtobondthesteelreinforcementtothemasonrysothatthereinforcementcanresistloadswiththemasonrycomponent.Thegroutingcellsincreasethebearingareaforresistinghighercompressiveloads;Thegroutingcellsenhancethewalltoresistthelateralload;Groutimprovetheperformanceoffireresistanceandwaterpenetrationformasonrybuilding.2.1.4ReinforcementKindofreinforcementbarsReinforcingbarsusedinmasonryconstructionareofthesamekindasthoseusedforconcreteconstruction,includingdeformedbarsandplainbars;Adequatecovershouldberequiredforreinforcingsteelbarstoprotectthemfromcorrosion.FunctionsofreinforcementSteelreinforcingbarsareusedinmasonrystructuretoenhancethestrengthofmasonrymembers,bothintensionandcompression;ReinforcingtypeSteelmeshreinforcedbrickmasonry;CompositebrickmasonrywithRCstructuralcolumnandbeam;Reinforcedconcreteblockmasonry.2)CompositebrickmasonrywallwiththestructuralcolumnsandbeamsThestructuralcolumn3)ReinforcedconcreteblockmasonryVerticalbarsinfilledcells1)SteelmeshinthebedjointofmasonrySteelmeshRCtoppingorreinforcedmortartopping4)CompositebrickmasonrywallwithRCtoppingorreinforcedmortartoppingReinforcingtypeTiesteelSteelmeshreinforcedbrickmasonryThesteelmeshreinforcementsof3-4mmindiameterareembeddedintothebedjoint(thehorizontallayerofmortar)withevery2-5coursesspacing;Steelmeshreinforcementscanrestrainthelateraldeformationofmasonryincompressionandresultsinincreasingofthecompressivestrengthofmasonry.2~5courseSteelmeshreinforcementsof3~4mmindiameter＋Steelmeshreinforcement3-4mmindiameterConsecutivebentreinforcement

Diameter≤8mmSteelmeshreinforcementscanrestrainthelateraldeformationofmasonryincompressionandresultsinincreasingofthecompressivestrengthofmasonry.Wheresteelmeshreinforcementisadopted,thediameterofthesteelbarsshouldbe3~4mm;2~5courseSteelmeshreinforcedbrickmasonryWhereconsecutivebentreinforcementisadopted,thediameterofthesteelbarsshallnotbegreaterthan8mm.CompositebrickmasonrywithRCstructuralcolumnsandbeam—ConfinedmasonryJointpartwithindentingbetweenthestructuralcolumnandbrickmasonrywallCompositebrickmasonrywithRCstructuralcolumnsandbeam—ConfinedmasonryConfinedmasonry:masonrystructuralwallsaresurroundedonallfoursidesusingstructuralcolumnsandbondbeams(ringbeams);MasonrywallisfilledinweakRCframe;Increasethecompressiveload-bearingcapacityandaseismiccapacityofmasonrywall.TheringbeamThestructuralcolumnThestructuralcolumn240×240Theringbeam240×180Steeltiebetweenthewallandthestructuralcolumn

MasonrywallSlabThestructuralcolumn:Atthefourcornersoftheexternalwall;Attheendoflargeopening(doororwindow);Attheintersectionbetweenthelongitudinalwallsandtransversewalls;Attheintersectionbetweenthegablesandinternallongitudinalwalls.TheringbeamThestructuralcolumnMasonrywallArchitecturalPlanofamasonrybuildingTheringbeam(closingform):Alongthehorizontaldirectionofthemasonrywall;Onthecornice;Onthefloorofabuilding;Attheelevationofthetopsurfaceofafoundation;Usingadditionalringbeamtoconnectthecutringbeam.RingbeamonthefloortopWindowforstairwellAdditionalringbeamAfterthewallsarebuilt,attachformwork.2.Setupformwork4.Formwork

removalAfterpouringconcreteintotheformwork,leavetheformworksafter24hoursatleast.1.Constructionofmasonrywalls3.PouringconcreteBeforepouringconcrete,thereinforcementsteelbars,includinglongitudinalbarsandstirrups,shouldbeplaced.ConstructionstepforthestructuralcolumnThestructuralconcretecolumnandtheringbeamcanconfinethewall,andassurebuildingunderstrongearthquaketoavoidcollapse,effectivelyimprovetheseismiccapacityofthebuilding;Makethestructurehaveenoughductilityanddeformationcapacity;Allthestructuralcolumnsandringbeamsliketensionelementsduringearthquake.Structuralcolumn

Ringbeam

Whyistheaseismicperformanceforthecompositewallwiththestructuralcolumnandringbeamimproved?2.2MechanicalperformanceofmasonrystructuresCompressivefailurecourseofbrickmasonry1）Stage1：verticalcrackingonthemasonryunit（0.5～0.7）Nu2）Stage2：continuouscracksonthemasonrywall（0.8～0.9）Nu3）Stage3：thewallisdividedintoseveralslendercolumns,thenwallfailed.

Material

Strength:Masonryunitstrength:10MPaMortarstrength:10MPaStage1Stage2Stage3Bearingcapacityofmasonrystructureunderloadmostlydependsonmechanicalpropertyofmasonrymaterials.Questions?1.Whydoestheverticalcrackonmasonrybrickunitfirstappear?2.Whyisthemasonrystrengthsmallerthanstrengthofmasonryunit?Strengthresults:Masonrystrength:4.2MPaMasonrystrength<Masonryunit2.AnalysisofcompressivestateofbrickmasonryMasonryunitundercomplexstressstate:non-uniformcompression,bending,shearEmortar<EbrickTendencyofdeformation:Lateraldeformationofmortar>LateraldeformationofbrickBrickMotarCompression+TensionformasonryunitCompression+CompressionforbedjointImperfectcontactsurface2.AnalysisofcompressivestateofbrickmasonryCompression+TensionformasonryunitCompression+CompressionforbedjointThemasonryunitisunderbidirectionalstressstateincludingverticalcompressionandhorizontaltension,whichleadtoreducingcompressivecapacityofmasonryunit.Hence,thecompressionstrengthofmasonrywallissmallerthanstregthofasinglemasonryunitunderverticalload.Mortarinthebedjointisinbiaxialcompression,andabletowithstandhighercompressivestressesthanstrengthofacubeofmortar,becausetherestraintonitslateraldeformationimposedbythemasonryunitsincreasesthecompressivestrength.3、MainfactorsaffectingthecompressivestrengthofthemasonryLayingqualityandcuredconditionThedifferentthicknessofbedjointleadstodifferentstrengthofmasonrystructure;Thethicknessofbedjointis8~12mm.Thegeometrydimensionoftheunit;Thelargerdimensionofheightformasonryunitcanstrengthenbendingandshearcapacity,andavoidtheearlycrackingontheunit.Thestrengthofmasonryunitandmortar;Deformationperformanceofmortar(i.e.modulus),flexibilityandmoistureretentionofmortar;Thesmallofdeformationofmortarcanlimitthelateraldeformation,therebyenhancecompressivestrength.fmisthemeanvalueofthecompressivestrengthofmasonry；f1、f2isthemeanvalueofthecompressivestrengthofmasonryunitandmortar,respectively；k1istheacoefficientdependingonthemasonryunittype;k2isaadjustmentcoefficientforlowstrengthmortar；

aisthefactordependingontheunitheight.Toomuchfactorsaffectingcompressivestrengthofmasonrystructure,soitisdifficulttoestablishthetheoreticalformulacomposingofallactingfactors;3.CalculatingformulaofmeancompressivestrengthofmasonryChinesemasonrycodeprovidesthefollowingformulatoestimatethemeanvalueofcompressivestrengthfmforthemasonrybasedon3000axialcompressiontests:TheMasonryStandards(Code)fromalloftheworldshavetodevelopthecalculatingapproachofmasonrystrengthbasedontestresults.Meanvaluesofthecompressivestrengthfm

(fromChinesecode)Typeofmasonryk1ak2Firedcommonbrick,Firedperforatedbrick0.780.5Iff2<1，k2=0.6+0.4f2Concretehollowblock0.460.9Iff2=0，k2=0.8Ashlars0.790.5Iff2<1，k2=0.6+0.4f2Rubble0.220.5Iff2<2.5，k2=0.4+0.24f2Note:f1isthemeanvalueofcompressivestrengthofmasonryunits(brick,blockorstone);f2isthemeanvalueofcompressivestrengthofmortar;k1istheafactordependingontheunittype;k2isaadjustmentfactorforlowstrengthmortar;aisthefactordependingontheunitheight.CalculatingformulaofcompressivestrengthfordifferentcountriesChapter3

Reinforcedconcreteblockmasonry(RM)shearwallstructureContents3.1StressanalysisofsectionforRMwall3.4Researchonreinforcedconcreteblockmasonry3.2Definitionofreinforcedconcreteblockmasonryshearwallstructure

3.3ProjectcasesofRMstructuresPrefaceManyun-reinforcedmasonrybuildingscollapsedduringTangshan(1976,China)earthquakeandWenchuan(2008,China)earthquake,indicatingitisnecessarytoreinforcemasonrystructureforimprovingaseismicperformance.Theuseofun-reinforcedmasonryhasbeenprohibited,especiallyinhighandmoderateseismicintensityareas.PrefaceWhyistheaseismicbehaviourforunreinforcedmasonrystructurespoor?Howtoreinforceconcretehollowblockmasonry?ReinforcedconcreteblockmasonrywallQuestion1:Poortensileandshearpropertiesofun-reinforcedmasonrystructureQuestion2:Wallreinforcementsteelbarsincludethehorizontalbarsandverticalbars;Verticalcanbeputinfilledcellsofblocks,horizontalreinforcementcanbeplacedinthebedjointorinthegroove.Reinforcementismainlyincorporatedwithmasonrytoresistcompressive,tensileandshearstressesandprovideadequateductilityduringearthquake.Itcanbeconsideredasassembledmonolithicconcreteshearwallstructure.Filledcell

Groove

RMwallundercombinedaxialandlateralloadsInitially,bendingstressesfromalowlateralloadarelessthanaxialcompressionstress.Tensilestressesdevelopwithincreasedlateralload;Aslateralloadincreasesfurther,thetensilestressincreasestothepointwherethemasonryatbasecracks.crackingAftercrackingthebendingmomentatthebaseisresistedbytheinternalmomentoftheresultantcompressiveforceinthemasonryandbythetensileforceintheverticalsteel;Asthewallnearsfailure,thestressinthemasonrytakeonanonlineardistribution,uptoalimitingstrain;Thetensionsteelsmayormaynotyieldbeforefailure,dependingonpercentageofsteelandlevelofload.3.1StressanalysisofsectionforRMwallhorizontalsteelcanresisttheresultingdiagonaltensileforce.Masonrywallsaremadefromconcretehollowblockunitswithallorpartialcellsgrouted,verticalandhorizontalreinforcementbars,andmortar.RMwallcanprovidetheadequatestrengthandductilitytoresistthegravityandearthquakeloads

comparedwithun-reinforcedconcreteblockmasonry.RMwallscombinetheperformanceofmasonrystructureandRCstructure.TestresultsandphenomenashowthatthemechanicalperformanceofRMwallissimilartoRCshearwallstructure.Wallverticalcross-section3.2Definitionofreinforcedconcreteblockmasonryshearwall——(RMwall)Case1:TheExcaliburHotel(inLasVegas,Nevada,in1989)ReinforcingmadeitpossibletouseRMshearwallstructureforhighbuildingatmoderateseismicintensityareas.Thewallsforlowerfloorswereconstructedusingconcreteblockswithacompressivestrengthof27.5MPaandwallthicknessof290mm.3.3ProjectcasesofRMstructuresCase2:AjiApartment(18storyinHarbin,China,in2003)-1story:RCframe-shearwallstructureforgaragewithlargeopenspace;1~5story:RCframe-shearwallstructureforcommercialstoragewithlargespace;6~18story:RMshearwallstructureconstructedusingconcreteblockunitshavingacompressivestrengthof20MPaandwallthicknessof190mm.RMwallstructureisnotusedforthelowerfloors,whichhouseashop,garageandcommercialstorageandrequirelargeopenspaces.ElevationofaBuilding(seepreviousbuildingphoto)RMwallstructureforresidenceRCframeorRCframe+RMwallforlargeopenspaceRCframecombinedwithshearwallsbettermeetthisrequirementforthelowerfloors.Step1:BlockworkStep2:SetreinforcementConstructionsequenceforRMshearwallstructureStep3:PouringconcreteintocellsandvibratingHorizontalreinforcement

Verticalreinforcement

ConstructionSiteforRMwallStructureConstructionSiteforRMwallStructureQuestions:Howtodowel,connectandanchortheverticalreinforcementsforRMwalls?Doweling,barlaplength,anchorageoftheverticalbarsforRMwallSteeldowelConnectingofthebarsConnectingofthebarsSteelanchorageThehollowofblockshouldbealigned;Thelaplengthisrequiredaccordingtoseismicintensity;TheReinforcementdrawingofaRMWallVerticalBarHorizontalBarDoorWindowWindowTheconstructionmoduleis100ormultipleof100mm;Thehollowsoftheconcreteblockmustbeinaline,otherwisetheverticalreinforcementcannotbeplaced;Thealternativeconstructionbetweenthelongitudinalwallandthetransversewalltoprovideconnectingofthem.InsulatingmaterialinsidethecontinuouscavitySandwichthermalinsulationcompositewall

BearingRMwall(190mm)Nonbearingwallbuiltofblock(90mm)HowisbuilttheexternalwallofRMshearwallstructureincoldareaslikeHarbin?SectiondrawingofexternalwallforRMexternalwall

窗部连梁详图窗洞口处圈梁截面配筋SectiondrawingofwalllocatedunderwindowforRMstructureHowtomanufacturethecolorfulsplit-faceconcreteblock?Colorsplit-faceconcreteblockSplit-faceconcreteblockisaspecialclassofdecorativeconcreteblockthathasarough,stone-liketexturecreatedbysplittingtheconcreteblockduringproduction.However,thecurrentuseofsplit-faceblockisalmostentirelylimitedtocommercialandinstitutionalbuildingsandnotyetwidespreadinresidentialbuildingsforexpensivecost.Colorsplit-faceconcreteblockPutpaintintothemiddleofconjoinedblockColorsplit-faceconcreteblockColorsplit-faceconcreteblockTodividealongthelinebyasharpblowEXPERIMENTALSTUDYONSTRUCTURALPERFORMANCEOFGROUTEDRCBLOCKWALL-BEAMCOMPOSITIONXimeiZhai

,YanfengGuoSchoolofCivilEngineering,HarbinInstituteofTechnology,China4.1ResearchprojectonreinforcedconcreteblockmasonrystructureContentIntroductionSpecimenDesignandFabricationTestInstrumentationandTestingProcedureTestResults

→StrainoftheLongitudinalBarsinTrimmerBeam;

→

StrainoftheVerticalBarsinRMWall;

→

StrainoftheHorizontalBarsinRMWall;

→

StructuralBehaviourofWall-BeamComposition.DiscussionaboutDepthofTrimmerBeamandWallOpeningConclusionIntroductionBlockTypeThereinforcedgroutedconcreteblockmasonry(RM)shearwallstructuresarepromotedinChinainsteadofmoretraditionalun-reinforcedclaybrickmasonry(URM).AdvantagesforRMoverURM:

Improvedbearingcapacityandearthquake-resistance.ReinforcedConcreteBlockMasonryStructure18LayerinHarbin,ChinaRMwallstructureisnotusedforthelowerfloors,whichhouseashop,garageandcommercialstorageandrequirelargeopenspaces.ElevationofaBuilding(seepreviousbuildingphoto)RMwallstructureforresidenceRCframe-shearwallforlargeopenspaceReinforced(RC)frameorRCframecombinedwithshearwallsbettermeetthisrequirementforthelowerfloors.墙体墙体墙体TrimmerBeam→墙体墙体墙体←TrimmerBeamThereinforcedgroutedconcreteblockwallsoftheflooraboveRCframesitonthecast-in-placeRCbeam(trimmerbeam).Thisformsareinforcedmasonrywall-beamcomposition,whichisstudiedinthispaper.AccordingtoChinesecode,theRCtrimmerbeamdepthtospanratioforURMwall-beamcompositionshouldbegreaterthanorequalto1/6forseismicdesign.TheobjectiveofthispaperistogainbetterunderstandingofperformanceofRMwall-beamcompositionunderverticaluniformload.ComparedtoURMwall-beam,RMwall-beamstructurehasgreaterstiffness.Thehigherstiffnesscanhelpreducingthedepthtospanratioforcast-in-placeRCtrimmerbeam,andthusincreasetheheightofthefloor.So,theobjectiveofthispaperisalsotoproposeanappropriatedepthtospanratioforatrimmerbeaminthewall-beamcomposition.Onesolidwall-beamcompositionandfivewall-beamcompositionswithopeningsinthewallweretestedandsometestresultsweregotten.g)SectionalSteelforTrimmerbeam;h)SectionalSteelforTop-Beam;i)BoltingSteelPlated)WB4