Bond Between steel tubes and Concrete relationship from AISC

[ahmadramadan]

I would like to calculate the bond between concrete and steel sections(steel tubes,etc)

I found one paper which define the bond relationship (Experimental Study on Shear Splitting Failure of Full-Scale
Composite Concrete Encased Steel Beams)
and I found fs=51.25629.544p
where p =steel area to section area
fs= bond stress between concrete and steel

So my questions are
1.I found in AISC 16.1-95 that reduction safety factor of 0.45 for bond between concrete and steel, but this is for filled composite member not encased(encased mean the tubes are not filled inside with concrete),so is there any section dealing with encased in the AISC (Hence I need this factor to use in the previous paper equation)
2.My second question the equation bond strength by AISC (In the same page is not clear to me ,variables are not clear, can anyone simplify it

Thank you

 

[MacGruber22]

Look higher on the same page "The force transfer mechanism of direct bond interaction shall not be used for encased composite members"

"It is imperative Cunth doesn't get his hands on those codes."

 

[ahmadramadan]

you are right, I found the statement,
I think the formula used in the paper mentioned is good, but I am looking for safety reduction factor as per LRFD method, can you suggest any thing in AISC

Thank you

 

[KootK]

What is your application? Composite beam? Composite column? Simple shear friction between two surfaces? The AISC code on composite shear transfer is dependent on the type of member being considered.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[ahmadramadan]

Beam, Encased Hollow tubes, not filled

Thank you all

 

[KootK]

I don't know of an AISC blessed bond stress that applies to this situation. AISC does, however, allow you three methods of designing encased steel beams:

1) Composite, without shear anchors, utilizing elastic stresses.

2) Using the plastic capacity of the steel alone but without worrying about local buckling effects.

3) Composite, with shear anchors, utilizing plastic stresses.

Even without a sanctioned bond stress, you've got what you need to design an encased beam.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.