Cyclic Performance of Steel Plate-Reinforced High Toughness-Concrete Coupling Beams with Different Span-to-Depth Ratios

In coupled shear wall or core wall systems, reinforced-concrete (RC) coupling beams are crucial to the seismic performance of the overall structure. These coupling RC beams, however, tend to undergo brittle shear failure, especially those with a small span-to-depth ratio (i.e., deep coupling beams). In this paper, an alternative RC coupling beam with high seismic resistance and high ductile behavior is proposed. The coupling beam is made of high-toughness concrete reinforced with an embedded vertical steel plate as well as steel bars. Three proposed steel plate-reinforced high toughness-concrete (PRHTC) coupling beams with different span-to-depth ratios (l/h=1.0, 1.5, and 2.0) were tested. All three PRHTC coupling beams behaved in a ductile manner with good hysteretic behavior and large energy-dissipating capacity. Both the embedded steel plates and the high-toughness concrete contributed greatly to the high performance of the PRHTC coupling beams. The test results also show that load-carrying capacity of the PRHTC coupling beams increases as the span-to-depth ratio decreased whereas deformation ductility remains stable.