钢筋轻质超高性能混凝土偏心受压柱力学性能试验研究

Experimental Study on the Mechanical Performance of Steel Reinforced Light-weight Ultra-high Concrete Eccentric Compression Columns

为明确钢筋轻质超高性能混凝土(LUHPC)偏心受压柱力学性能,文中设计制作了配筋率为0%、1.39%、2.05%、3.57%的四种试件,进行偏心距为0,30,60和120 mm的加载试验,研究了配筋率和偏心距对钢筋LUHPC偏心受压柱破坏形态、极限承载力、荷载-侧向位移曲线的影响规律.试验表明:在相同配筋率下,当偏心距从0~120 mm时,其钢筋LUHPC偏心受压柱的极限承载力下降68.6%~86.2%.在相同偏心距下,当配筋率从0%增大到3.57%时,其极限承载力增加了18.0%~51.4%,考虑受拉区LUHPC拉应力的作用,基于LUHPC的等效应力矩形系数α_(1),β_(1)和偏心距增大系数η_(L),建立了大、小偏心钢筋LUHPC偏心受压柱极限承载力计算修正公式,计算结果与试验值比较吻合,平均误差为3%.

In order to clarify the mechanical properties of reinforced lightweight ultra-high performance concrete(LUHPC)columns under eccentric compression,four kinds of specimens with reinforcement ratios of 0%,1.39%,2.05%and 3.57%were designed and manufactured,and loading tests with eccentricity of 0,30,60 and 120mm were carried out.The effects of reinforcement ratio and eccentricity on the failure mode,ultimate bearing capacity and load-lateral displacement curve of reinforced LUHPC eccentrically compressed columns were studied.The test shows that under the same reinforcement ratio,when the eccentricity is from 0 to 120mm,the ultimate bearing capacity of reinforced LUHPC eccentrically compressed columns decreases by 68.6%to 86.2%.Under the same eccentricity,when the reinforcement ratio increases from 0%to 3.57%,its ultimate bearing capacity increases by 18.0%~51.4%.Considering the tensile stress of LUHPC in the tensile zone,based on the equivalent stress rectangular coefficientsα_(1),β_(1) and eccentricity increasing coefficientη_(L) of LUHPC,a modified formula for calculating the ultimate bearing capacity of large and small eccentric reinforced LUHPC eccentrically compressed columns is established.The calculated results are in good agreement with the experimental values,with an average error of 3%.