Cyclic Behavior of Slender Diagonally Reinforced Coupling Beams according to Transverse Reinforcement Spacing

Coupled shear walls system are frequently used as the primary components of the lateral force resisting system in medium and high rise buildings. Suitably devised coupling beams may be able to not only survive over large displacement demands, but also serve as a primary source for energy dissipation. Recently due to limitations in story height, coupling beams are relatively slender, with aspect ratios on the order of 2~3.5. In these beams, the effectiveness of diagonal reinforcement is questionable because of the shallow angle. The objective of this study is to evaluate shallow diagonal reinforcement coupling beams and to simplify the reinforcement details of diagonal reinforcement coupling beams by reducing the transverse reinforcement around the beam perimeter that is required for the confinement of diagonal reinforcement coupling beams. Experiments were conducted using three diagonal reinforcement coupling beams with 3.5 aspect ratio provided by KCI(2012) under reversed cyclic loads to evaluate the hysteretic behavior of the specimens. The test results show that slender diagonal reinforced coupling beam specimens with either code-complied transverse reinforcement or half the code-complied transverse reinforcement produced satisfactory strength and deformation capacity.??? ????????? 2014?????? ???????????????, 2015?????? ?????????????????? ????????? ????????? ?????? ????????? ???????????????. ????????????:C0191948, 2015R1A2A1A1505524