Topic: Bond Between FRP bar and Concrete


I am using ATENA 3d and I am trying to model the bond between the FRP bars and the concrete in order to monitor the crack width of reinforced concrete beams under static loading. My question is concerned with the bond definition:

I selected define "Bond for Reinforcement" then, "user defined". I found that I have to define bond stress-slip relation.

What I need to know exactly:

1- Do I need to define bond stress-slip depending on experimental results or
2- I have to get the values of the bond stress-slip from an existing model in the literature which I shall select or
3- There are equations in ATENA where, I can calculate from it the values of the curve.

4- The "tau1 (t1)" is defined in case of cyclic loading only?

Thank you

Re: Bond Between FRP bar and Concrete

1. Yes, you can define it according to experimental results if you have such data and you can interpret it.
2. You can check ModelCode 2010 cl. but it is stated there that bond parameters of FRP bars should be calibrated on basis of experiments, so you have to follow #1 anyway
3. There are predefined generators for ModelCode 1990 (which is not valid now) and Bigaj (1999). However, these generators are only applicable to steel reinforcement.
4. Yes, you don't need it for static loading. See cl. 2.8.3 ATENA Theory for details.

Re: Bond Between FRP bar and Concrete

Dear omar1990,
just an additional note to prevent possible confusion: the relation to be defined is STRENGTH-slip, see also Troubleshooting, 2.2.11 How can I take reinforcement bond into account?


Re: Bond Between FRP bar and Concrete

Thank you so much for your reply, I realized it.

For the sake of measuring the crack width values and the micro-behaviour, is it preferred in my case to use fixed or rotated crack model please?