Beam-Column Joints (BCJs) are crucial elements in Reinforced Concrete (RC) frame structures since their behaviour strongly affects the seismic performance of structures. Indeed, the respect of hierarchy principles in the design of these kind of structures leads to a BCJs preservation from premature failure, allowing the structural members to develop their full strength and ductility. As well known, the design of BCJs is performed as the last step of the frame design and, if code joint verifications are not satisfied, the BCJ needs to be re-designed. This also can lead to a re-design of the structural members framing into the joint and, often, also to a re-definition of the architectural design. For these reasons, be aware if the structural design complies with the code prescriptions since the early stages of the design process can help the engineers and architects, also leading to a time saving.

In this paper, a new graphical tool for supporting the design of BCJs in RC frame structures is proposed. Diagrams (called nomograms) are presented, consisting in charts that lead to achieve the BCJ geometric dimensions and hoop amount so that the NTC18 B-CJ verifications are satisfied. The proposed nomograms can be used for all types of joints, and with any kind of geometry since they are dimensionless. Nomograms can simplify the RC building design since they offer an indication of the joint verification outcomes even from the early stages of the design process, i.e., at the moment in which the structure is conceived and built within a finite element model.