반복 횡하중을 받는 장방형 기둥-슬래브 접합부의 이력거동에 대한 철근비의 영향

Abstract

In this investigation, results of laboratory tests on six reinforced concrete flat plate interior connections with elongated rectangular column support which has been used widely in tall residential buildings are presented. The purpose of this study is to evaluate an effect of slab reinforcement ratio and column aspect ratio(βc=c₁/c₂) on the hysteretic behavior under earthquake type loading. The aspect ratio of column section was taken as 0.33~3(c₁/c₂=1/3, 1/1, 3/1) and the flexural reinforcement ratio was taken as 0.01 and 0.015(ρ=1.0%, 1.5%). Other design parameters such as concrete strength were kept constant as fck=40㎫, respectively. Gravity shear load(Vg) was applied by 30 percents of nominal vertical shear strength(0.3V?) of the specimen. Experimental observations on punching failure pattern, peak lateral-load and story drift ratio at punching failure, stiffness degradation, displacement ductility index and energy dissipation in the hysteresis loop were achieved and discussed in accordance with different reinforcement and column aspect ratio. Eccentric shear stress model of ACI 318-05 was evaluated with experimental results.