Seismic Behavior of a Coupled-Wall System with HPFRCC Coupling Beams

Coupled reinforced concrete (RC) shear walls are often used in zones of high seismic risk. The RC coupling beams that connect individual shear walls must transfer adequate force between adjacent walls and, at the same time, are expected to contribute significantly to energy dissipation through ductile deformation during strong seismic shaking. These stringent requirements usually result in a dense configuration of reinforcement, which complicates erection of RC coupled wall systems. High performance fiber reinforced cementitious composite (HPFRCC) materials have a unique strain hardening behavior in tension that translates into enhanced shear and bending response at the structural level. Recent research has shown that the use of HPFRCC in coupling beams can result in a relaxation in reinforcing details while maintaining good strength characteristics and deformation capacity. This paper discusses the seismic performance of an 18-story coupled wall system in which HPFRCC coupling beams are used instead of traditional RC beams. System performance is evaluated through various parameters including inter-story drift and rotation of critical structural parts. The ability of HPFRCC coupling beams to provide acceptable performance is discussed in light of the simulation results.