Highrise Residential - Concrete

[Cals33]

Please clarify this concept for me. Why are modern residential highrise designed with concrete and not steel. I am particularly interested in knowing why we would see more modern steel commerial highrise and seldom residential steel highrise.

Any explaination and clarifications would be appreciated. Thanks

 

[bandraoi]

Cost and the availability of source materials.
If you live in a place where there is a steel industry nearby then you'll go for steel, if there are lots of quarries then concrete.

 

[dbuzz]

The Australian Steel Institute publishes a brochure, Seven Reasons, which I'll summarise here:
1. Earlier Occupation
Fit-out of the lower levels can commence much sooner because propping of formwork is not required
? Work can proceed on a number of fronts with steel construction
? Early occupation means you get a return on your investment sooner
2. Reduced Risks
? Reduced OH&S exposure
? Off-site fabrication
? Reduced on-site workforce
? Reduced delays due to weather
? Reduced on-site congestion
? Reduced truck movements
3. Larger Column-Free Space
? Larger column-free space is provided by the long-spanning capability of structural steel
? Architectural freedom is provided by the column-free space giving greater ?exibility to building owners and occupiers
? More attractive space is provided by the smaller columns that are typically found in a steel building
4. “Future-Proof” Investment
It is easier to make major changes to a building framed in structural steel.
? Beams and columns can be strengthened to take extra loads by welding on additional plates
? New ?oor penetrations can be simply installed
? Steel offers a light-weight ‘add-a-top’ frame which makes it an ideal construction method for expanding existing buildings in any direction
5. Technology
Extensive research over the past decade has lead to more economical steel framed buildings.
? Advances in ? re engineering have drastically reduced the cost of protecting a steel frame without compromising safety
? Structural design advances result in more economic designs
? Advances in computer aided design and drafting together with computer-controlled fabrication has improved both the cost and speed of delivering a steel solution
6. Sustainable Construction
Sustainability during the life of the building
? Long lasting and durable
? Easily renovated or refurbished
? Easily strengthened or modi? ed
? Extend vertically or horizontally
Sustainability after the life of the building
? Demountable and reuseable as a complete building or as individual steel elements
? Easily demolished
? 100% recyclable
7. Competive Cost

 

[Structr]

A major factor is story height. Architects need it minimized, which flat plate concrete slab, PT or non-PT is at an advantage.

 

[TPNY]

Also think about fire-proofing cost. For a steel building, you will have to pay for extra fireproofing materials between those steel beams and columns. For residential structures, fire-rated materials must enclose each liveable unit, and it may be more economical to kill two birds with one stone: concrete continuous structural element + continuous fire-rated element.
Well... that was just an assumption, I really don't know if that is the only reason.

 

[jike]

There are many considerations that go into selecting a steel or concrete structure.... bay size, loading, fire rating, code restrictions on height, material availability, labor market, costs and rates of inflation, architectural considerations, schedule, tenant contracts, etc.

An important consideration in making concrete competetive is that the structure must be repetitive (floor to floor heights and bay sizes) so that forms can be reused multiple times. Formwork can be 50% of the structural cost.

Generally, with concrete flat plates, lower floor to floor heights can be achieved which translates into savings in exterior skin, elevators and vertical mechanical runs. Recently, the steel industry has been working with the precast market to develop steel products that are more competetive with concrete on floor to floor heights.