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Re: cored concrete beams

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Nicholas,

You are absolutely correct. The engineer must be aware of the fire/high
temperature issue, and not blindly accept the "promises or guarantees" of
suppliers and contractors.

Our approach at SCI is to use auxiliary anchorage devices when dealing with
fire issues, and strongly are against the use of the CFRP laminates or
sheets as the Primary load resisting element.

Just because, as a previous message indicated that Sika strips were "fire
tested", does not mean that the installed system is fire proof or fire
resistant.

There is a whole series of other issues to be addressed when specifying
"new" technology, and the soon to be issued ACI 440 Guidelines for FRP
Products will be very helpful.

jim korff, PE


----- Original Message -----
From: "Nicholas Blackburn" <NBlackburn(--nospam--at)ipd-oak.com>
To: <seaint(--nospam--at)seaint.org>
Sent: Tuesday, June 27, 2000 1:57 AM
Subject: RE: cored concrete beams


> The biggest problem that I have encountered with the use of carbon fiber
and
> fiberglass reinforcing materials is the ability to adequately fireproof
> them.  The intumescent material provided by the manufacturer is not rated
> for overhead use.  There are UL rated assemblies but these are not always
> viable due to size constraints.  You should be aware that the epoxies used
> are incredibly toxic once they start burning or vaporizing.  Since the
fire
> department is not likely to be aware of the presence of these toxic
> materials, you should take every precaution to ensure adequate fire
> resistance.  There is also a rapid loss of strength associated with
elevated
> temperatures.
>
> Since there is no bottom reinforcing left I would use a welded mild
> reinforcing solution to repair the beam with lots of special inspection
etc.
>
> Good luck
>
> Nick Blackburn, PE
>
>