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RE: Concrete vs. Steel

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Scott,

There are many factors that warrant consideration whether a structure should
be steel or concrete.  I have designed extensively in both.  You have to
look at the local inertia to a degree.  If it is a small project, go with
the local flow.  If it is big, you need to take a harder look at the
economics.

I can give you the perspective from international construction and domestic.

Office buildings:
Domestic & Western Europe:
Labor is expensive, materials are relatively cheap. 
In low rise 1 and 2 story.  The economics will drive the structures to
steel. 
In smaller office building structures 2 to 10 stories, they will be probably
be steel.  In the colder areas winter concrete placement can complicate
concrete placement.  The only debate would be precast versus steel.  If it
is a class A office (long spans and few columns) it will probably be steel.
In taller structures (over 10 stories), they could go either way, and it is
based on economics.  The economics equation will include fire proofing
considerations which can push it to concrete (either cast in place or
precast).

Office buildings:
If it is in Russia it will probably be precast, which minimizes the material
expense and allows for cold weather construction.
If it is in Vietnam, Indonesia, or similar SE Asian countries they will go
to cast in place concrete which uses a lot of labor, but indigenous rebar
mills are common.

Industrial buildings:
Domestic and Western Europe:
In the 70's steel prices were climbing rapidly, then Nucor-Yamato built
their new plant and took over the market in the US.  Precast concrete
structures took a back seat to steel.  Currently, steel industrial
structures allow for
future modifications more readily.  The inclination is to steel.

Russia is still precast.  India, Vietnam, Indonesia will still be into cast
in place even for petro-chemical plants just because it is cheaper.  They
sacrifice future flexibility for the economics.

In water treatment plants it is concrete whenever possible because of
aggressive chemicals.  The only steel will be for roof structures.

In blast resistant structures it will be concrete, because of the larger
mass and redundancy.

With all that, you still have to run the numbers.

Regards,
Harold Sprague, P.E., Chief Structural Engineer
The Neenan Company