|
Title |
Effect of Aspect Ratio and Diagonal Reinforcement on Shear Performance of Concrete Coupling Beams Reinforced with High-Strength Steel Bars
|
|
Authors |
김선우(Sun-Woo Kim) ; 장석준(Seok-Joon Jang) ; 윤현도(Hyun-Do Yun) ; 서수연(Soo-Yeon Seo) ; 천영수(Young-Soo Chun) |
|
DOI |
https://doi.org/10.4334/JKCI.2017.29.1.043 |
|
Keywords |
연결보 ; 고강도 철근 ; 세장비 ; 전단성능 ; 변형능력 coupling beam ; high-strength steel bar ; aspect ratio ; shear performance ; deformation capacity |
|
Abstract |
As per current seismic design codes, diagonally reinforced coupling beams are restricted to coupling beams having aspect ratio below 4. However, a grouped diagonally reinforcement detail makes distribution of steel bars in the beam much harder, furthermore it may result in poor construction quality. This paper describes the experimental results of concrete coupling beam reinforced with high-strength steel bars (SD500 & SD600 grades). In order to improve workability for fabricating coupling beams, a headed large diameter steel bar was used in this study. Two full-scale coupling beams were fabricated and tested with variables of reinforcement details and aspect ratio. To reflect real behavior characteristic of the beam coupling shear walls, a rigid steel frame system with linked joints was set on the reaction floor. As a test result, it was noted that cracking and yielding of reinforcement were initially progressed at the coupling beam-to-shear wall joint, and were progressed to the mid-span of the coupling beam, based on the steel strain and failure modes. It was found that the coupling beams have sufficient deformation capacity for drift ratio of shear wall corresponding to the design displacement in FEMA 450-1. In this study, the headed horizontal steel bar was also efficient for coupling beams to exhibit shear performance required by seismic design codes. For detailed design for coupling beam reinforced with high-strength steel, however, research about the effect of variable aspect ratios on the structural behavior of coupling beam is suggested.
|