Comp

Composite Construction 1

Introduction to composite construction of buildings

General 2

Steel and concrete These two materials complete one another: ◆

Concrete is efficient in compression and steel in tension

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Concrete encasement restrain steel against buckling

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Protection against corrosion and fire

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Steel bring ductility into the structure

General 3

Aspects for using composite structures: ◆

Architectural

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Economical

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Functionality

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Service and Flexibility

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Assembly

Aspects for using composite structures Architectural: ◆

Longer spans

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Thinner slabs

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More slender column

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More generous opportunities for design

4

Aspects for using composite structures Economical:

5

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Reduction of height reduces the total of the building --> saving area of cladding

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Longer spans with the same height --> column free rooms

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Additional storeys with the same total height of building

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Quicker time of erection: ➙ Saving costs, earlier completion of the building ➙ Lower financing costs ➙ Ready for use earlier thus increasing rental income

Aspects for using composite structures

6

Functionality: ◆

Fire protection by using principles of reinforced concrete in which the concrete protects the steel

Aspects for using composite structures

7

Service and building flexibility: ◆

Adaptable structures ➙ Modification during the life of the building ➙ Modify services without violating the privacy of other occupants ➙

Accommodation of service facilities in the ceiling within a false floor in a coffer box running along the walls

Aspects for using composite structures

8

Assembly: ◆

Working platforms of steel decking

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Permanent shuttering

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Reinforcement of profiled steel sheetings Speed and simplicity of construction

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Quality controlled products ensure greater accuracy

Construction methods 9

Traditionally two counteracting methods of construction could be observed both connected with special advantages but also disadvantages worth mentioning. ◆ Conventional concrete ◆ Construction in steel construction method + freedom of form and shapes + easy to handle

+ high ratio between bearing capacity and weight + prefabrication

+ thermal resistance

+ high accuracy

- time-consuming shuttering

- low fire resistance

- sensitive on tensile forces

- need of higher educated personal

Construction methods 10

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Composite Construction comparing these two methods a combination of both presents the most economic way + higher bearing capacity + higher stiffness + plastic redistribution

Construction elements 11

composite slab

composite column

composite beam floor = beam + slab

Construction elements 12

Composite slabs ◆

Reinforced concrete slab

in-situ concrete on shuttering partially prefabricated slabs

fully prefabricated slabs

Construction elements 13

Slabs ◆

Pre-stressed concrete slabs

Construction elements 14

Slabs ◆

Profile steel sheeting Interlock between steel and concrete

frictional

mechanical

end anchorage

Construction elements 15

Beams ◆

Conventional and innovative composite beams

Construction elements 16

Beams ◆

Types of shear connectors

Construction elements 17

Columns ◆

Examples of composite columns

Construction elements 18

Joints ◆

Example of vertical shear transfer between beam and column bracket for the lower flange reinforcement

weld seam

removed after concreting

contact piece bracket with shear connectors

shot-fired nails

Examples 19

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

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

Examples 20

Millennium Tower (Vienna - Austria)

33,05 m

42,342,3 m m

Concrete slab

Concrete core

Composite Slim floor beams Composite columns

Composite frame

Examples 21

Millennium Tower (Vienna - Austria)

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

Examples 22

Citibank Duisburg (Duisburg - Germany) ◆ ◆ ◆

15 storeys Total height 72 m Total ground floor 14500 m2

Examples 23

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

4 storeys Ground dimensions 60 x 30 m Max. span length 10.58 m with 26 cm slim floor slab (= l/40)

Examples 24

Parking deck “DEZ” (Innsbruck - Austria)

Erection of composite columns over 2 storeys Assembly of prefabricated concrete slabs

Examples 25

60

260 200

Parking deck “DEZ” (Innsbruck - Austria)

Cross section of the slim-floor beam and slab -200 mm concrete slab -60 mm prefabricated concrete elements -steel beam: web 165/20 mm flange 245/40 mm -headed studs: 22 mm

Concluding summary 26

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

Economy

●

Architecture

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Functionality

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Service and building flexibility

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Assembly