2축 편심 축력을 받는 고강도 정사각형 RC 기둥의 성능 평가

Abstract

Analysis and design of RC column sections under combined biaxial bending and axial compression are difficult because a trial and adjustment procedure is necessary to find the depth and inclination of the neutral axis satisfying the equilibrium equations. For simplified practical design, biaxial design constant(β) which interprets the relation of biaxial bending and equivalent uniaxial bending is adopted in ACI 318-99 code, PCA Load Contour Method. But the provided design constant is limited to concrete compressive strength of 420kgf/㎠. And this leads the effect of concrete strength to be minor. The purpose of this study is to examine the effect of high strength concrete on the biaxial bending moment strength of reinforced concrete columns and furnish design data of high strength concrete columns. Fifteen square section(200 x 200㎜) columns with the variable of concrete compressive strength (350, 585, 650kgf/㎠), axial load ratio(O.2Po, 0.35Po, 0.5Po) and inclination of loading{O, 22.5, 45°) were tested and compared to the results of nonlinear analysis by DRAIN 3DX and biaxial design constant(β) of PCA Load Contour Method.