1. Introduction to composite construction of buildings

2. These two materials complete one another:
General
Steel and concrete
These two materials complete one another:
Concrete is efficient in compression and steel in tension
Concrete encasement restrain steel against buckling
Protection against corrosion and fire
Steel bring ductility into the structure

3. Aspects for using composite structures:
General
Aspects for using composite structures:
Architectural
Economical
Functionality
Service and Flexibility
Assembly

4. Aspects for using composite structures
Architectural:
Longer spans
Thinner slabs
More slender column
More generous opportunities for design

5. Aspects for using composite structures
Economical:
Reduction of height reduces the total of the building --> saving area of cladding
Longer spans with the same height
--> column free rooms
Additional storeys with the same total height of building
Quicker time of erection:
Saving costs, earlier completion of the building
Lower financing costs
Ready for use earlier thus increasing rental income

6. Aspects for using composite structures
Functionality:
Fire protection by using principles of reinforced concrete in which the concrete protects the steel

7. Aspects for using composite structures
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

8. Aspects for using composite structures
Assembly:
Working platforms of steel decking
Permanent shuttering
Reinforcement of profiled steel sheetings
Speed and simplicity of construction
Quality controlled products ensure greater accuracy

9. Construction methods
Traditionally two counteracting methods of construction could be observed both connected with special advantages but also disadvantages worth mentioning.
Conventional concrete construction method
Construction in steel
+ high ratio between bearing capacity and weight
+ freedom of form and shapes
+ prefabrication
+ easy to handle
+ high accuracy
+ thermal resistance
- low fire resistance
- time-consuming shuttering
- need of higher educated personal
- sensitive on tensile forces

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

11. Construction elements

12. Construction elements
Composite slabs
Reinforced concrete slab

13. Construction elements
Slabs
Pre-stressed concrete slabs

14. Construction elements
Slabs
Profile steel sheeting
Interlock between steel and concrete
mechanical
frictional
end anchorage

15. Construction elements
Beams
Conventional and innovative composite beams

16. Construction elements
Beams
Types of shear connectors

17. Construction elements
Columns
Examples of composite columns

18. Construction elements
Joints
Example of vertical shear transfer between beam and column

19. Millennium Tower (Vienna - Austria)
Examples
Millennium Tower (Vienna - Austria)
55 storeys
Total height 202 m
Total ground floor m2
Capital expenditure about 145 million Euro
Time of erection: 8 months

20. Millennium Tower (Vienna - Austria)
Examples
Millennium Tower (Vienna - Austria)
Composite columns
Concrete core
Composite Slim floor beams
Concrete slab
42,3 m
Composite frame
33,05 m

21. Millennium Tower (Vienna - Austria)
Examples
Millennium Tower (Vienna - Austria)
Total time of erection: 8 month max. speed 2 to 2.5 storeys per week!

22. Citibank Duisburg (Duisburg - Germany)
Examples
Citibank Duisburg (Duisburg - Germany)
15 storeys
Total height 72 m
Total ground floor m2

23. Parking deck “DEZ” (Innsbruck - Austria)
Examples
Parking deck “DEZ” (Innsbruck - Austria)
4 storeys
Ground dimensions 60 x 30 m
Max. span length m with 26 cm slim floor slab (= l/40)

24. Parking deck “DEZ” (Innsbruck - Austria)
Examples
Parking deck “DEZ” (Innsbruck - Austria)
Erection of composite columns over 2 storeys
Assembly of prefabricated concrete slabs

25. Parking deck “DEZ” (Innsbruck - Austria)
Examples
Parking deck “DEZ” (Innsbruck - Austria)
Cross section of the slim-floor beam and slab mm concrete slab mm prefabricated concrete elements -steel beam: web 165/20 mm flange 245/40 mm -headed studs: 22 mm

26. Concluding summary
Composite construction is popular for buildings because of following aspects:
Economy
Architecture
Functionality
Service and building flexibility
Assembly