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Bill Cain responded to Bill Allen's original mail:
> Bill-
> 
> In a message dated 97-04-08 21:07:28 EDT, you write:
> 
> >I've been asked to look at a tilt wall building with recent fire damage.
> >I haven't seen the structure yet, but I understand the purlins and GLBs
are
> >charred. There is also some spalling in the tilt wall panels.
> >
> >Is anyone familar with guidelines that will help determine what has to be
> >replaced and what can remain. My common sense is telling me that the
> >purlins are probably bad, the GLBs might be OK and I have some concern
> >about the spalled concrete since this is probably due to the expansion of
> >the reinforcing steel.
> >
> >Thanks,
> >Bill Allen
> 
> You might want to check on the date the building was built.  I have run
into
> several buildings built in the late '40's and early '50's in which the
> glu-lams were made with interior glue.  One fire damaged building I
> investigated had glue line deterioration that apparently occurred due to
> heavy soaking during fire suppression.  To my knowledge, beams frabicated
> since that time have used exterior glue almost exclusively so it should not
> be a problem with more recent structures. 
> 
> Bill Cain, SE
> Oakland, CA
> 

Another reason you might want to ask is how old is the structure
relates to the concrete.  As you know, the water in concrete
hydrates over time. The younger the concrete, the more water.  I was
involved in a fire damage problem about 7 years ago and, while my
recollection of the incident fades with time, I seem to remember the
"expert" we hired saying something about the younger the concrete the
better because there is more water present which acts as kind of a
heat sink because of the energy required to change it to a gaseous
state (boil it). There is likely to be more surface spalling as this
water boils, but the effects are relatively shallow.  This particular
project was a P/T flat plate project with multiple slab pours making
up a single floor. The slab formwork for one of the pours caught on
fire and it spread to the reshores and closure strips for the
adjacent pour sections.  Most of the areas in these adjacent pour
sections which were close to the source of the fire had what
appeared at first glance to be severe spalling but because the slabs
were only a few weeks old at the most, the spalling was relatively
shallow and it was judged to be cosmetic.  Also, exposure time to the 
heat source is important.

Michael Bramhall, SE
Seattle, WA


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From: "Michael Bramhall" <mab(--nospam--at)mail.nwlink.com>
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Date: Wed, 9 Apr 1997 22:11:17 +0000
Subject: Re: Fire Damages Structures
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