Seismic Design of Shear Strength of Reinforced Concrete Interior Beam-Column Joints

• Main Authors: Tsai, Chia-Sheng, 蔡家盛
• Other Authors: 黃世建
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/00683604440749977860

碩士 === 國立臺灣科技大學 === 營建工程系 === 92 === American ACI 318-02 Code requires that the RC beam-column joints be detailed with the similar amount of hooks in the end regions of columns for seismic resistance. This empirically determined amount of hooks creates a congested joint which is very difficult to construct with, especially for the high strength concrete joints. Moreover, the ACI 318-02 Code formula is not applicable in assessing the shear strength of the seismically insufficient joints. The objective of this study is to declare the roles of joint hooks and to define a least amount of joint hooks. According to the softened strut-and-tie model, the recommended amount of hooks is sufficient for the full development of shear strength, and the recommended detailing of hooks is flexible enough for construction. Six interior reinforced concrete beam-column joints were tested under reverse cyclic loading. Test results indicated that the major function of the joint hoop is to carry shear as a tension tie and to constrain the width of crack. This study found that the joint hoop play no role in confining concrete core as required by the ACI 318-02 Code. Less amount of hoop reinforcement with a wider spacing could be used without significantly affecting the performance of joints. The softened strut-and-tie model is capable in estimating the shear strength of joints for both the seismic design and the seismic retrofitting.