1 composite construction introduction to composite construction of buildings

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Composite Construction Composite Construction Composite Construction Composite Construction

Introduction to composite Introduction to composite construction of buildingsconstruction of buildings

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GeneralGeneralGeneralGeneral

These two materials complete one These two materials complete one another:another:

SteelSteel and concreteand concrete

Concrete is efficient in compression and steel in Concrete is efficient in compression and steel in tensiontension

Concrete encasement restrain steel against Concrete encasement restrain steel against bucklingbuckling

Protection against corrosion and fireProtection against corrosion and fire

Steel bring ductility into the structureSteel bring ductility into the structure

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GeneralGeneralGeneralGeneral

Aspects for using composite Aspects for using composite structures:structures:

ArchitecturalArchitectural

EconomicalEconomical

FunctionalityFunctionality

Service and FlexibilityService and Flexibility

AssemblyAssembly

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Aspects for using composite Aspects for using composite structuresstructuresAspects for using composite Aspects for using composite structuresstructures

Architectural:Architectural:

Longer spansLonger spans

Thinner slabsThinner slabs

More slender columnMore slender column

More generous opportunities for More generous opportunities for designdesign

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Economical:Economical: Reduction of height reduces the total of Reduction of height reduces the total of

the building --> saving area of claddingthe building --> saving area of cladding

Longer spans with the same height Longer spans with the same height

--> column free rooms--> column free rooms

Additional storeys with the same Additional storeys with the same total height of buildingtotal height of building

Quicker time of erection:Quicker time of erection: Saving costs, earlier completion of the buildingSaving costs, earlier completion of the building Lower financing costsLower financing costs Ready for use earlier thus increasing Ready for use earlier thus increasing

rental incomerental income

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Functionality:Functionality: Fire protection by using principles of reinforced Fire protection by using principles of reinforced

concrete in which the concrete protects the steelconcrete in which the concrete protects the steel

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Service and building flexibility:Service and building flexibility: Adaptable structuresAdaptable structures

Modification during the life of the buildingModification during the life of the building Modify services without violating the privacy of Modify services without violating the privacy of

other occupantsother occupants Accommodation of service facilitiesAccommodation of service facilities

in the ceilingin the ceiling

within a false floorwithin a false floor

in a coffer box running along the wallsin a coffer box running along the walls

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Assembly:Assembly: Working platforms of steel deckingWorking platforms of steel decking

Permanent shuttering Permanent shuttering

Reinforcement of profiled steel sheetings Reinforcement of profiled steel sheetings Speed and simplicity of constructionSpeed and simplicity of construction

Quality controlled products ensure greater accuracyQuality controlled products ensure greater accuracy

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Construction methodsConstruction methodsConstruction methodsConstruction methods

Traditionally two counteracting methods of construction could be observed both connected with special advantages but also disadvantages worth mentioning. Conventional concrete Conventional concrete

construction methodconstruction method

Construction in steelConstruction in steel

++ freedom of form and freedom of form and shapesshapes

++ easy to handle easy to handle

++ thermal resistance thermal resistance

-- time-consuming shuttering time-consuming shuttering

-- sensitive on tensile forces sensitive on tensile forces

++ high ratio between bearing high ratio between bearing capacity and weightcapacity and weight

++ prefabrication prefabrication

++ high accuracy high accuracy

-- low fire resistance low fire resistance

-- need of higher educated need of higher educated personalpersonal

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Construction methodsConstruction methodsConstruction methodsConstruction methods

Composite ConstructionComposite Construction

comparing these two methods a combination of both comparing these two methods a combination of both presents the most economic waypresents the most economic way

++ higher bearing capacity higher bearing capacity

++ higher stiffness higher stiffness

++ plastic redistribution plastic redistribution

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Construction elementsConstruction elementsConstruction elementsConstruction elements

composite column floor = beam + slabcomposite beam

composite slab

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Composite slabsComposite slabs

Reinforced concrete slabReinforced concrete slab

in-situ concrete on shuttering partially prefabricated slabs fully prefabricated slabs

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SlabsSlabs

Pre-stressed concrete slabsPre-stressed concrete slabs

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SlabsSlabs Profile steel sheetingProfile steel sheeting

Interlock between steel and concreteInterlock between steel and concrete

frictionalfrictional mechanicalmechanical

end anchorageend anchorage

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BeamsBeams Conventional and innovative Conventional and innovative

composite beamscomposite beams

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BeamsBeams Types of shear connectorsTypes of shear connectors

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ColumnsColumns Examples of composite columnsExamples of composite columns

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JointsJoints Example of vertical shear transfer Example of vertical shear transfer

between beam and columnbetween beam and columnremoved after concreting

bracket with shear connectorscontact pieceweld seam

reinforcement

bracket for the lower flange

shot-fired nails

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ExamplesExamplesExamplesExamples

Millennium Tower Millennium Tower (Vienna - Austria)(Vienna - Austria)

55 storeys55 storeys Total height 202 mTotal height 202 m Total ground floor 38000 m2Total ground floor 38000 m2 Capital expenditure about 145 million EuroCapital expenditure about 145 million Euro Time of erection: 8 monthsTime of erection: 8 months

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Composite columns

Concrete core

Composite Slim floor beams

Concrete slab

42,3 m

Composite frame

42,3 m

33,0

5 m

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Total time of erection: 8 monthTotal time of erection: 8 monthmax. speed 2 to 2.5 storeys per week!max. speed 2 to 2.5 storeys per week!

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Citibank Duisburg Citibank Duisburg (Duisburg - Germany)(Duisburg - Germany)

15 storeys15 storeys Total height 72 mTotal height 72 m Total ground floor 14500 m2Total ground floor 14500 m2

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Parking deck “DEZ” Parking deck “DEZ” (Innsbruck - Austria)(Innsbruck - Austria) 4 storeys4 storeys Ground dimensions 60 x 30 mGround dimensions 60 x 30 m Max. span length 10.58 m with Max. span length 10.58 m with

26 cm slim floor slab (= l/40)26 cm slim floor slab (= l/40)

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Parking deck “DEZ” Parking deck “DEZ” (Innsbruck - Austria)(Innsbruck - Austria)

Erection of composite columns over 2 storeysErection of composite columns over 2 storeysAssembly of prefabricated concrete slabsAssembly of prefabricated concrete slabs

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Parking deck “DEZ” Parking deck “DEZ” (Innsbruck - Austria)(Innsbruck - Austria)

Cross section of the slim-floor beam and slabCross section of the slim-floor beam and slab-200 mm concrete slab-200 mm concrete slab-60 mm prefabricated concrete elements-60 mm prefabricated concrete elements-steel beam:-steel beam: web 165/20 mmweb 165/20 mm

flange 245/40 mmflange 245/40 mm-headed studs: 22 mm-headed studs: 22 mm

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Concluding summaryConcluding summaryConcluding summaryConcluding summary

Composite construction is popular Composite construction is popular for buildings because of following for buildings because of following aspects:aspects:

EconomyEconomy

ArchitectureArchitecture

FunctionalityFunctionality

Service and building flexibilityService and building flexibility

AssemblyAssembly

1 composite construction introduction to composite construction of buildings

Documents

u steel

concrete u concrete

u thinner slabs u

flexibility u assembly

steel slide

u reduction of height

slender column u

buckling u protection