Although all the member design checks have been fulfilled, I get the "Not Covered Reinforcement" result. What is the reason?
It can happen that all design checks are fulfilled for a particular member or set of members, but a "Not Covered Reinforcement" result is still output. See also Image 01 and Image 02.
The reason for this is that the distribution of the "Provided Reinforcement" on the upper and lower positions is generated from the rebar arrangement within the cross-section.
The rebars above the center of gravity are assigned to the "upper position" and the rebars below the center of gravity are assigned to the "lower position". This means that the distribution of the "Provided Reinforcement" does not consider the actual distribution of the zero line within the cross-section, and checks which rebar is actually in the tension zone.
However, the actual distribution of the zero line within the cross-section is checked during the design. Thus, the rebars that have been geometrically assigned to the "lower reinforcement" (the provided reinforcement distribution) can be mathematically assigned to the tension reinforcement. This can be seen in Image 03. The rebars marked in red have been assigned geometrically to the lower reinforcement. However, the stress distribution within the cross-section shows that they are also subjected to tension and apply to the design checks accordingly. In the design, all members (marked in red and green in Image 03) are applied. Therefore, all the design checks are fulfilled at this location, although the distribution of the "Not Covered Reinforcement" suggests otherwise.