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FW: 60,000 psi limit on Reinforceing bars

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The problem with utilizing reinforcement with yield higher then used in calculations is that it might create brittle failure mechanism by crashing concrete in compressive zone before steel ductile failure.  You want your steel to yield before the concrete reaches its compressive strength

My $0.02 worth.

Regards,

Sasha Itsekson, PE


 ----------
From: 	T. Eric Gillham[:gk2(--nospam--at)kuentos.guam.net]
Sent: 	Friday, June 26, 1998 6:36 AM
To: 	seaoc list
Cc: 	ITSEKSON SASHA
Subject: 	Fw: 60,000 psi limit on Reinforceing bars

Michael:

I am unclear as to the basis for you statement that fy cannot exceed 60
ksi.  Doesn't Section 21.2.5.1 cover this (see below)?

Also, the original post that started this discussion led me to believe that
the gentlemen DID have the mill certificates, and that was the reason for
his question.  As I understood it, he was asking basically whether he could
use the steel with a higher than 60ksi yield point, to which I would answer
yes of course.  As to whether he would use 60ksi in his calculations, I
guess there are differing opinions, though.  But this brings up another
point: if a designer knew from experience that the steel in his area had
ultimate tensile stress capacities of up to 95ksi, would he be wise to
assume 1.25*60=75ksi for computing ultimate flexural capacities?  Strictly
using the code, this is all that would be required, right?  But I would say
it is not in his best interest to take the code at face value, when he has
evidence that it does not apply in his particular situation.

Pehaps you are looking at it from a case where, say, someone wanted to use
Grade 75 instead of 60?  If so, then I would agree that the code prohibits
such a course of action.

T. Eric Gillham PE