Question:
Can I also use the horizontal branch of the stress-strain curve for cross-section design in RF‑CONCRETE Members?
Answer:
In cross-section designs, RF‑CONCRETE Members or CONCRETE calculates with the stress-strain diagram for reinforcing steel according to DIN EN 1992‑1‑1, 3.2.7(2)a; that is, with an increasing upper branch up to f-tk and a strain limit of ε-ud = 0.025.
In RF‑CONCRETE Members or CONCRETE, there is no option to switch to a design with a horizontal branch according to 3.2.7(2)b.
However, if necessary, you can calculate with a user-defined material, in which f-tk = f-yk.