The effective concrete tensile strength fct,eff,wk at the time of cracking can be specified in Window 1.3 Surfaces in the "Limit of Crack Widths" tab.
Effective Concrete Tensile Strength at Time of Cracking in RF-CONCRETE Surfaces
As of RFEM Version 5.06, there is the option in RF‑CONCRETE Surfaces to adjust the effective concrete tensile strength at the time of cracking. At the start of the SLS design, the program checks whether the internal forces can cause cracks in the concrete. For this, the effective concrete tensile strength at the time of cracking is applied. You can adjust the strength via the factor. The calculation details display the adjusted value.
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