• Registered: 2017-03-15
  • Posts: 4

Topic: Model parameters

In the Atena Theory manual 2.2.12.3 is given suggestions for model parameters, which refers to the compressive strength. It is not stated whether it is the medium or the characteristic strength.
I've tried to compare compressive and tensile strength and E-modulus with values from table 3.1 in EC2 to find out which one to use, but there seems to be no correspondence between the Eurocode and Atena theory manual.
Which values should I use if I have a C40 concrete?

Regards
Sigurd Steen

Quote Post 1

  • From: Cervenka
  • Registered: 2007-08-08
  • Posts: 35

Re: Model parameters

Dear Sigurd, sorry for late reply. The table in ATENA Theory manual Section 2.2.12.3 is not based on any code, but rather on having a best fit. So if you need to use this  CC3DNonLinCementitious3 material and want to have values as much as possible to the code values, I would recommend to use the following table for the parameters that are not available in the code and for others use the  the code values. The code gives values anyway just for fc, ft, eps_v,t.

Whether to start from mean of design depends on the purpose of the analysis. If you intend to simulate the average response then start from mean value. If you need to consider some safety, i.e. make an analysis for checking ultimate limit state then I would recommend to start from the design value of strength. Otherwise you need to consider some suitable safety format for nonlinear analysis. For more description about this I can refer you to fib model code 2010 or to some papers on our website:

http://www.cervenka.cz/assets/files/pap … roclaw.pdf

Let us know if you have further comments or questions.

With best regards

Jan

Quote Post 2

3 Reply by sigurss (edited by sigurss 2017-05-04 13:27:56)

  • Registered: 2017-03-15
  • Posts: 4

Re: Model parameters

So if I have a C40 concrete (having a medium strength of 48 MPa), should I then use the table values for fc=40, or the table values for fc=48 (require interolation)?

Quote Post 3

  • From: Cervenka
  • Registered: 2007-08-08
  • Posts: 35

Re: Model parameters

Of course if your concrete is somehow between two strength values, then you have a choice either use the closest one or interpolate. Of course more accuracy should be obtained by interpolating.

Regards

Jan

Quote Post 4

  • Registered: 2017-03-15
  • Posts: 4

Re: Model parameters

The question is if the strength values (fc) in the table are mean or characteristic values, but since you wrote that it is not based on any code, I must assume it is a mean value, and therefore I should use fc=48 for a C40 concrete.

Quote Post 5