In connection with the analytical SLS calculation, I get implausibly large values for the crack width and deformation in the RF‑CONCRETE add-on modules. What is the cause and how can I fix the problem?


Regarding the analytical calculation of SLS, you should note that the calculation is based on a provided or applied reinforcement for SLS.

The provided reinforcement can result, for example, from the ultimate limit state design, the defined basic reinforcement, or the automatically determined required reinforcement for SLS. The reinforcement applied to the SLS design can be displayed graphically.

Figure 01 - Provided Reinforcement

Problem Cause:

If there are too small or no reinforcement results from ULS or the basic reinforcement in some areas and no required reinforcement is determined for SLS at the same time, the serviceability limit state design is performed without or with too small reinforcement. In this context, very high results may occur during the deformation, for example. Also, there may be poor convergence.

Figure 02 - Error Message "Poor Convergence"

Problem Solution:

It is necessary to ensure that there is a reinforcement in each area of the structural system. For this, you can apply a basic reinforcement or a minimum reinforcement, for example.

Figure 03 - Definition of Basic or Minimum Reinforcement


Deformation Deformation results Deformation analysis Poor convergence State II (cracked) Not designbale


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