early sixties, when A36 came out, there was a big push to build higher
buildings to take advantage of limited real estate. The concrete
industry responded by striving for higher strength concretes and trying
to prove that they could build higher buildings also. Likewise, the
asphalt paving industry versus the concrete slab industry in roads. I
am sure that safety was always a consideration, but as I remember the
main driving force was competition, i.e. the dollar.
Gary
Jordan Truesdell, PE wrote:
> There _was_ a smiley on the end of that sentence, but... presuming
> concrete hasn't changed, yes. Physics, in the realm that we deal,
> hasn't changed. NACA airfoils developed in mid 20th century still
> provide the same lift that they did back then, so air hasn't changed
> either.
>
> I can't argue that lumber has changed, but the laws of mechanics
> hasn't. If you want to update material properties, be my guest. If
> you ask me to do 5 hours of calculations to come up with an answer
> that is 5-10% away from the one I can do in 3 minutes with a pencil,
> I'd rather you not prohibit me from using the old version.
>
> I'm fine with advancement which materially increases safety or
> simplifies the job of design (thereby reducing the possibility of
> errors, and ultimately increasing safety), but many changes don't seem
> to be falling into either category. Things seem to be changing for
> the sake of change (oooh, pretty-shiny!) - where lives are at stake,
> I'm not a big proponent of that mindset.
> Jordan
>
>
> Ralph Kratz wrote:
>> I guess you're (facitiously) suggesting that if the 1962 ACI code (my
>> first) had been "right" we wouldn't have had to have all these
>> revisions since then, right? :)
>>
>> Ralph
>>
>>
>> Sent from my iPhone
>>
>> On Jan 23, 2008, at 4:06 PM, "Jordan Truesdell, PE"
>> <seaint2@truesdellengineering.com
>> <mailto:seaint2@truesdellengineering.com>> wrote:
>>
>>> Why not do it right the first time? Then we wouldn't need cycles at
>>> all.;-)
>>> Jordan
>>>
>>>
>>>>
>>>>
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