Need a book? Engineering books recommendations...

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

Re: Concrete Fdtn at High Temps

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Ron,

If I get the picture, wouldn't steel roller or rocker bearings, a hanging
detail, or even a heat exchange type of bearing be better than resting the
pipe directly on or in the concrete?  1000 deg is pretty warm for mass RC
especially if there will be any temperature cycling.  The bars are starting
to soften at that temperature.  I guess cover will help but then you'll see
cracking without some extra detailing.  Is there any velocity to the vent
gas?

cmd

-----Original Message-----
From: MSSROLLO(--nospam--at)aol.com <MSSROLLO(--nospam--at)aol.com>
To: seaint(--nospam--at)seaint.org <seaint(--nospam--at)seaint.org>
Date: Monday, September 07, 1998 9:47 AM
Subject: Concrete Fdtn at High Temps


>I am working on a project where I have to support a steel pipe used as a
vent.
>The pipe is routed up the exterior wall and is estimated to be about  1000
>degrees F.
>
>I want to support the pipe from below with a concrete pedestal/footing but
am
>not well-versed in concrete at elevated temperatures of this magnitude.
The
>pipe will be secured to the building for lateral loading, therefore, the
>footing is only supporting the gravity weight of the pipe (about 14 kips).
>
>Since the pipe is connected to the concrete pedestal, I am sure the
concrete
>will elevate in temperature.  Anyone got any thoughts on how to best design
>for the potential elevation in temperature or any means to isolate the base
of
>the pipe so that only minimal temperature rise takes place?
>
>In addition to this, the pipe is free to elongate up the wall.  It is only
>supported vertically at the base.  If I do not restrain the pipe from
moving
>upwards, I do not see needing any reinforcement around the circumference of
>the pipe.  The pipe will be free to expand radially and longitudinally.  Is
>there any obvious flaw in that thinking?  I have already adjusted the
modulus
>of elasticity, Fy and the thermal expansion coefficient for the elevated
>temperature.  The pipe is not made from a heat-treated material.
>
>Thanks for any help
>Ron Martin, PE
>
>
>
>