When performing the fire resistance design in RF‑CONCRETE Members, the acting internal forces (for example, My,Ed,fi) are applied that do not correspond to the internal forces of the applicable determination of internal forces. What is the reason?


In the fire resistance design, the acting internal forces are determined again if taking into account the thermal expansion of the concrete and the reinforcing steel and the precamber due to the temperature difference (Figure 01).

If the thermal expansions and the precamber are not taken into account, the acting internal forces should correspond to the internal forces of the calculation from RFEM or RSTAB (Figure 02).

To what extent it is allowed to deactivate the thermal expansions and precambers, has to be checked in the context of the applicable standard.


Fire resistance Internal forces Precamber Thermal expansion


Contact us

Did you find your question?
If not, contact us via our free e-mail, chat, or forum support, or send us your question via the online form.

+49 9673 9203 0


RFEM Main Program
RFEM 5.xx

Main Program

Structural engineering software for finite element analysis (FEA) of planar and spatial structural systems consisting of plates, walls, shells, members (beams), solids and contact elements

Price of First License
3,540.00 USD
RSTAB Main Program
RSTAB 8.xx

Main Program

The structural engineering software for design of frame, beam and truss structures, performing linear and nonlinear calculations of internal forces, deformations, and support reactions

Price of First License
2,550.00 USD
RFEM Concrete Structures

Add-on Module

Design of reinforced concrete members and surfaces (plates, walls, planar structures, shells)

Price of First License
810.00 USD
RSTAB Concrete Structures

Add-on Module

Linear and nonlinear analysis of reinforced concrete members with reinforcement concept

Price of First License
810.00 USD