Anchorage Behavior of Headed Bar in Beam-Column Joints

• Main Authors: Wun-liang Gao, 高文良
• Other Authors: Chien-Kuo Ghiu
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/tzg32e

碩士 === 國立臺灣科技大學 === 營建工程系 === 100 === In this study, headed bars are adopted to replace traditional standard hooks for avoiding reinforcement crowding in the beam-column joints. Seven full size experiments (four of them are interior beam-column connections and three of them are exterior beam-column connections) were conduct to investigate the influence of headed bars on beam-column joints. Not only to understand the anchorage behavior of headed bars in beam-column joints, but to comprehend the effect on flexure moment of beams. The issue on whether the performance of beam-column joints with different arrangements of head bars satisfy the seismic requirement is also discussed. For interior beam-column joints with two types of arrangement, i.e., butt and splices, the strength and ductility of the beam-column joints are found to be satisfactory. Additionally, for butt arrangement with enough anchorage length, the yielding of reinforcement and crush of concrete at beam end are obvious during incremental loading vertically. For the exterior beam-column joints, this study recommends the seismic resistant anchorage length of headed bars should be the ACI 318-08 provision multiplied by 1.23 times on condition that the clear spacing of headed bars is 2.2db, the beam-column joint belongs to the low shear ratio and strong column-weak beam pattern.