Experimental and Numerical Study of Cyclic Performance of Reinforced Concrete Exterior Connections with Rectangular-Spiral Reinforcement

Abstract

This paper introduces a new shear reinforcement beam-column joint mechanism—the twisted opposing rectangular spiral—and carries out numerical and experimental investigates. Converting the conventional discontinuous shear reinforcement system into a continuous system in different reinforced concrete structural elements improves energy dissipation capacity and ductility. The proposed reinforcement has an inclined characteristic that intersects shear cracks at a more favorable angle. In addition, the reinforcement considerably eliminates slip observable at the hooks of conventional stirrups, resulting in the reduction of shear resistance. The seismic performance of the reinforcement is compared to conventional shear reinforcement and normal rectangular spiral systems. Six full-scale beam-column joint mechanisms were designed per Eurocode CEN-EC8 for low- and high-ductility modules. Quasi-static cyclic loads are used to simulate seismic loads as recommended by a widely used building code. In this paper, the experimental results of the six specimens are compared with the numerical results of finite-element analysis. The investigation concludes with the introduction of a newly proposed connection, resulting in the improvement of its capacity to dissipate energy, lateral strength, and ductility.