Evaluation of the bearing capacity of fiber reinforced concrete sections under fire exposure

Aim of the paper is the evaluation of the bearing capacity of fiber reinforced concrete (FRC) sections, without any traditional steel reinforcement, subjected to different values of the fire duration. At this purpose, bending moment (M)-axial force (N) interaction envelopes are defined, through an analytical model based on the direct integration of the hot or residual mechanical properties of the material, throughout the member cross section. Finally, a parametric survey, specifically related to tunnel segments, with different geometries and FRC materials allows highlighting the worst (or better) scenarios.