Hi,
In simple words, detailing of composed mint is necessary for the structural steel and also for 10 force concrete structures to attend strength and durability. The figure is attached with shows the joining details of beams and columns.
The main parts of them should be cracked near the columns and the length. It is in the ratio of 1:4. Any other cases the beam re pass must not pass from the column rebars outer surface which comprises the concrete cover.
Instead of detailing the above different detailings are the wind for rehabilitation and strengthening the damaged elements.