Dual-Phase steel re-bars for High-Ductile R.C. Structures Part 2: rotational capacity of beams

The article presents an application of an innovative type of reinforcing bars, made by dual-phase (DP) steel, for the design of high-ductile r.c. structures in seismic areas. In particular a comparison of the capacity, in terms of ductility, of r.c. structural elements reinforced using dual-phase (DP) steel bars with that of identical structures reinforced with the traditional Tempcore steel bars, currently used in practice, has been carried out. To this purpose an analytical procedure enabling the calculation of the plastic rotational capacity of r.c. beams has been set up, obtaining the bending moment-curvature law through an expressly developed model in order to reproduce "tension-stiffening" phenomenon.