Guy's
I am trying to get detailed calculations for crack widths in RSA, although I input limiting crack widths in the reinforcement calculations, I wondered if there was a detailed output given by robot without going into the spreadsheet calculator extension.
Further I have veiwed the 2 youtube tutorials on the spreadsheet calculator, and was wondering if there are any further tutorials or learning material for it.
Thanks again.
Gavin
Rafal,
I've contacted authors of the book example and they both agree there's an error in their example (regarding cracks width calculation).
They are thankful for good remarks. 🙂
They think that this "c" variable in EC2 (7.11) shouldn't be called "c" because according to EC2 4.4.1.1. (1) - "c" stands for "The concrete cover is the distance between the surface of the reinforcement closest to the nearest concrete surface (including links and stirrups and surface reinforcement where relevant) and the nearest concrete surface.", but that's completly another thing to discuss.
After all, I am glad that error is in their example, not Robot. 😄
Still waiting for the second part of the answer (regarding calculation of deflections).
Still waiting for the second part of the answer (regarding calculation of deflections).
Almost ready.
Translating now.
The RSA does not take into account the effect of shrinkage.
In the attached case, the effect of shrinkage is: 9.43 * 10 ^ -6/4.183 ^ 5 = 0,225 -> 22%
If from book result 27.9 we subtract (22%* 27.9 😃 6.28 we get 21.6mm
Minor differences: when we detect that the concrete is "typical" (ie, as in the EC2 table) , the Young modulus is taken from the table and not calculated.
The differences in the position of the rebar can change the moment of inertia.
However, this would explain the differences of a few rather than 10%
When you set “Display diagrams for all combinations”, we get instead of 21.6mm 20.9mm -> 0.7mm.
(Difference near 3% already may be due to other differences I mentioned earlier)
The mistake is located in taking the final calculation of the elastic deflection as of the envelope of all combinations and not as an envelope of QPR combinations. Need to be corrected in software.
I've finally manage to carefully read your post.
Thank you very much Rafal for your effort.
I am glad we resolved this. Hope it will be corrected soon.
in you pic you have bar position in m with 5 marks after coma, i have only 2 marks. How to fix it? Didnt find anything about that in job pref-s..
Hello, gentleman,
Sorry for butting in, but I have a question regarding crack calculation.
I have to design a septic tank, and I would like to calculate / check width of crack with DISREGARD of effect of concrete in tensile zone (I want to know the additional amount of reinforcement, when I calculate a panel as if it already is cracked – I hope I am explaining it understandably).
To disregard the effect of concrete in tensile zone, I have to delete (or set value as 0 MPa) a tensile strength of concrete, but in “Custom material properties” tab there is no such value to change.
So, maybe there is a different way to define tensile strength of concrete?
Thank you in advance,
Best regards,
Paul.