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Title |
Influence of Concrete Strength and Lateral Ties on Behavior of High-Strength Concrete Columns Subjected to Eccentric Compressive Load
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Keywords |
기둥 ; 띠철근 ; 고강도콘크리트 ; 연성 ; 배근간격 ; 편심비 Column ; Lateral ties ; High-strength concrete ; Ductility ; Tie spacing ; Eccentricity ratio |
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Abstract |
This study was focused on the effect of concrete strength and lateral ties of concrete columns subjected to eccentric compressive loads. The twenty-four concrete columns with 200㎜×200㎜ square cross-section were tested. The main variables were concrete strength, spacing and configuration of lateral ties, and eccentricity ratios. From the experiment, the followings were investigated ; 1) In all cases, it was observed that the increase of concrete compressive strength led to the decrease of ductility. Also, as the eccentricity ratios increased, the effect of ductility enhancement by lateral ties decreased. 2) As the ties spacing decreased from 100㎜ to 30㎜ the magnitude of axial load acting on the concrete column showed an enhancement of 1.1~1.2 times and the descending curve after a peak moment presented a smooth decline. 3) The high-strength concrete columns required a design of lateral ties to increase the volumetric ratios and density of tie spacing to sustain a proper strength and ductility. Accordingly, regardless of concrete strength, the current AIK design code to specify the maximum tie spacing of concrete columns was proven to lead to the poor strength and ductility for seismic design. Therefore, it is necessary to develop a new seismic design code that connects volumetric ratios and tie spacing of concrete columns with concrete strength.
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