Is it possible in RF‑CONCRETE Surfaces to model a prefabricated slab or an element slab with different reinforcement layouts, for example, a reinforcement layer in a precast element and another reinforcement layer in the cast-in-place concrete extension?


If the ultimate limit state is only considered, it is possible to define a different concrete cover by reinforcement direction in RF‑CONCRETE Surfaces (see Figure 01). Once the serviceability limit state is also designed, both reinforcement directions must be adjacent to each other. The different concrete cover by reinforcement direction cannot be taken into account anymore.

Consideration of 3D Design - Shell
In the case of the design in a 3D structure, the element is considered as a shell. Both the moments and axial forces can act here, which are transformed into the design membrane forces. These design membrane forces are then used to determine the required reinforcement. In connection with the transformation from moments and axial forces, the smaller lever arm from both reinforcement directions is applied. Thus, only one governing lever arm is assumed for both directions.

Consideration 2D Design - Slab
In the case of the design in a 2D structure, the surface element is considered as a slab. Only the moments act, which are designed with the corresponding lever arm of the direction. Thus, each direction is supposed to have its respective lever arm.


Concrete cover Lever arm Element slab Prefabricated slab Precast element Cast-in-place concrete extension


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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

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RFEM Concrete Structures

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

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