Experimental Investigation of a Plastic Hinge Relocation Concept Using Enlarged Cross-Sections for Precast RC Beam–Column Connections

Abstract

Plastic hinge relocation can reduce damage within reinforced concrete beam–column connections by shifting inelastic deformations away from the connection region. This study experimentally investigates a relocation concept for precast reinforced concrete assemblies based on enlarged beam cross-sections. Four 1:3.5-scale specimens were subjected to quasi-static cyclic loading: one reference specimen and three specimens with increasing relocation distances. The hysteretic response, stiffness degradation, energy dissipation, damage distribution, beam rotation, and concrete surface strain were evaluated. In all relocated specimens, the measurements confirmed that inelastic deformations concentrated near the intended hinge location, while no visible shear damage developed at the beam–column interface. Compared with the reference specimen, the relocated configurations developed 86–175% higher yielding forces and 30–62% higher peak forces, mainly because the reduced effective lever arm increased force and moment demand. They also accumulated more than twice the hysteretic energy over their completed loading histories and showed higher minimum equivalent viscous damping after yielding. The results demonstrate that enlarged beam cross-sections can control the location of inelastic deformation; however, increasing relocation distance also increases force, rotational, and localized deformation demands at the relocated critical section.