Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Old Concrete Design

[Subject Prev][Subject Next][Thread Prev][Thread Next]
While we are on the subject of Old Timers for steel, I would like to ask a
concrete question for the same group. 

I am working a renovation project of an old department store structure built
in 1956 or 1957.  It is a flat slab, 2 way construction.  The general notes
state the reinforcing steel is ASTM A305 and state the following:

     Only Rail or Hard Grade shall be used for column verticals.

     All other reinforcing may be intermediate grade steel.

What does this mean?  What is the yield strength of rail, hard and
intermediate steel?

Also, older concrete design typically used bent truss bars, bending the
bottom bars up to top bars as they neared the support.  I am pretty sure we
don't do that anymore.  Unfortunately my experience in pure concrete frame
design is limited so I'm not totally positive about that, but, why don't we
use bent bars like in the olden days?

There is not any indication on the drawings for Live Loading.  I would assume
it was designed for at least 100 PSF, but I need to do some calculations to
verify it.  Do any of you remember what the code requirements would have been
for a department store designed in 1955?

Any other suggestions that would be helpful in working with older concrete
buildings would be appreciated.