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- Highly developed joining technique; swift assembly of the frame is made
possible. This facilitates the further dismantlement to cover a larger area,
creating extra time-gain.
- Industrialized production; pre-fabrication in the factory ensures shorter
production times, and higher levels of quality control than on the building
site. Because of computer assisted production, large production series
are no longer required, bringing custom productions and small building
volumes within a competitive range.
- The transfer of activities to the factory and fast assembly possibilities make
short building times possible.
Less on-site labour; this makes smaller building site facilities possible.
Shorter building times and reduced building site facilities imply a reduced
temporary impact on the environment and lower building site costs.
- Easy to reconstruct or adjust to a later renovation or adjustment with new
requirements. Drilling, welding, and cutting are possible. If needed, beams
or columns can be strengthened by means of reinforcement plates.
- Great resistance; a steel frame can absorb much energy because of its
plasticity, making it resistant to progressive collapse. A steel frame can
absorb a lot of vibrations.
- Suited for complex constructions; because of its great strength the material
can support heavy concentrated loads. This enables many different types of
supporting constructions, which in turn gives great freedom in the design of
the load-bearing construction.
- No large building area required; the assembly can be done with relatively
small cranes, transporting the separate parts from the truck/train wagon to
the site swiftly and smoothly. This is of particular advantage for inner city
projects.
- The total weight of the complete building will be considerably less than
that of a concrete construction. This makes lighter foundations possible,
reducing costs and saving space.
- High residual value, low environmental impact; the steel from demolition
works can easily be recycled. The scrap metal can be utilised as a coolant in
the production process and can promote a higher output when manufacturing
new steel.
The choice also implies certain limitations:
- Steel is less fire resistant. The sheer strength, yield strength, and elastic
modulus decrease at higher temperatures. At 400 to 500°C already, the yield
strength is almost equal to the actual strength, which can lead to severe
plastic deformations. In case of a fire, according to the actual standard
curve, this material temperature is already attained after 20 to 30 minutes.
In case of an actual fire, this takes roughly 40 minutes.
- Corrosion; steel will, when exposed to oxygen and moisture, oxidise and
therefore has to be protected against corrosion. This is usually done by
covering the material with layers of paint made from red lead, zinc, coal
tar epoxy etc. Smaller parts can be thermally or electrolitically zinc plated.
An adequate execution will provide protection over a long period of time,
resulting in warranty periods of 10 years and longer.