Answer:
No, unfortunately this is not possible. In the current stage of development of RFEM 5 and RSTAB 8, it is only possible to design rectangular and circular cross-sections using the RF‑CONCRETE Members or CONCRETE add‑on module.
If you select rib members and regular members in a reinforcement group for the design in the RF‑CONCRETE Members add-on module, the rib members will be removed automatically from this reinforcement group. The corresponding message appears, as shown in Image 01.
If you only select one rib member in the reinforcement group for the design, a message appears that the fire resistance design is not possible for this cross-section type.
