Need a book? Engineering books recommendations...

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

RE: [Fwd: Really Questioning 9-11 [Book]]

[Subject Prev][Subject Next][Thread Prev][Thread Next]
The yield strength and modulus of elasticity of steel drops as the
temperature rises. ASD, page 6-3 has a good introduction to the effect of
heat on steel. It gives examples of decreased yield strengths of 0.77 @
800F, 0.63 @ 1000F, and 0.37 @ 1200F. AISC does not directly address these
effects since most structural steel is used at ambient environmental
temperatures. ASME Boiler and Pressure Code (Section VIII, Div 1) has
allowable material strength for steel used at elevated temperature. ASME
STS-1 Steel Stacks has design values for various metals at elevated
temperatures.

Steel also shows metallurgical changes when used at high temperatures.

Bill Scott, P.E.; S.E
VECO Alaska Corp
949 E. 36th Ave., Suite 500
Anchorage, AK 99508
Phone: 907-762-1655
Fax: 907-762-1734
Cell: 907-748-5644
 

-----Original Message-----
From: Gale45man [mailto:gale45man(--nospam--at)yahoo.com]
Sent: Friday, March 18, 2005 1:44 PM
To: seaint(--nospam--at)seaint.org
Subject: Re: [Fwd: Really Questioning 9-11 [Book]]


If it is true that "At 800 degrees, steel loses most
tensile strength" then the galvanizers should be
pulling pretzels out of their vats (pure zinc melts at
850 deg F).  Did you mean 1800 deg F (not 800 deg F)?

Here are some excerpts from the AISC FAQ...

The strength of steel remains essentially unchanged
until about 600°F. The steel retains about 50% of its
strength at 1100°F. The steel loses all of its
capacity when it melts at about 2700°F. However, for
design purposes, it is usually assumed that all
capacity is lost at about 2200°F.


The duration and the maximum temperature of a fire in
a building compartment depends on several factors
including the amount and configuration of available
combustibles, ventilation conditions, properties of
the compartment enclosure, weather conditions, etc. In
common circumstances, the maximum temperature of a
fully developed building fire will rarely exceed
1800°F. The average gas temperature in a fully
developed fire is not likely to reach 1500°F.
Temperatures of fires that have not developed to
post-flashover stage will not exceed 1000°F.

d a v e   e v a n s 


		
__________________________________ 
Do you Yahoo!? 
Yahoo! Mail - now with 250MB free storage. Learn more. 
http://info.mail.yahoo.com/mail_250

******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
* 
*   This email was sent to you via Structural Engineers 
*   Association of Southern California (SEAOSC) server. To 
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you 
*   send to the list is public domain and may be re-posted 
*   without your permission. Make sure you visit our web 
*   site at: http://www.seaint.org 
******* ****** ****** ****** ******* ****** ****** ******** 


******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
* 
*   This email was sent to you via Structural Engineers 
*   Association of Southern California (SEAOSC) server. To 
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you 
*   send to the list is public domain and may be re-posted 
*   without your permission. Make sure you visit our web 
*   site at: http://www.seaint.org 
******* ****** ****** ****** ******* ****** ****** ********