When can we call a beam a beam? 7

[struggle67]

Hi,

Someone told me that if a beam is not stiff/deep enough, it wont behave like a beam and attract all the loadings like a beam would. It will be like localized thickening of slab or like a beam in the column strip of a flat slab.

I think that he is right but I couldn't find any defination in the code. Why codes do not differentiate it? Is there any way to differentiate or should I just rely on FEM results?

And Wish you all HAPPY NEW YEAR!

 

[Guest090822]

It’s easier to call things “structural elements”

The terms beam, stringer, girder are all the same from a functional standpoint, but terminology varies from industry to industry.

Look at the people here that can’t agree on OP’s question!

 

[KootK]

50% of balanced is fairly heavy: neutral axis depth is 0.3* effective depth for 400MPa reo and 0.003 concrete stain, and into the territory where moment redistribution is limited or not permitted. Is it 50% of the code limit for tension-controlled, so more like 0.2* effective depth?

You are 100% correct. I've been doing 50% of ACI's old [rho_max] which amounts to:

[50% x 75% x rho_balanced] = 3/8 x rho_balanced

Thanks for the correction and sorry for the delay. I lost track of this one.

 

[MSUK90]

It's from the Canadian concrete code as is used as a metric for determining when a beam is stiff enough to be considered a "stiff support" for the purposes of slab design.

Very good reference.
Can you please share the excerpt from the code or the exact clause reference please?
I do not have my hands and experience on Canadian Standards..

 

[KootK]

I've actually already posted screen shots of the code clause above as well as the symbol definitions. Let me know if you're unable to locate it after a closer look.