SRPE套管约束RC柱偏压力学性能试验研究

Experimental Research on the Mechanical Properties of SRPE Pipe Confined Reinforced Concrete Circular Columns Subjected to Eccentric Compression

针对西部强盐渍土/盐湖地区的钢筋混凝土(RC)桥梁墩柱的严重腐蚀问题,提出新型材料组合结构“钢骨架聚乙烯塑料复合管(SRPE)约束RC柱”,为研究其偏心受压力学性能,进行了8根SRPE套管约束钢筋混凝土柱和4根无套管约束对比柱的偏压试验,获得了试件破坏形态和荷载-轴向位移曲线,进而分析了SRPE套管压力等级、偏心距、长细比等设计参数对试件偏心受压力学性能的影响规律,并给出了偏压承载力计算公式,供工程应用参考。研究结果表明:SRPE套管对钢筋混凝土偏压柱的极限承载力和延性有显著提升;SRPE套管压力等级越高,试件承载力的提高效果越好,但对延性的影响不明显;试件的极限承载力随着偏心距和长细比的增加而减小;试件的延性随着长细比的增大而降低;对比试件的柱中峰值挠度要远小于SRPE套管试件的柱中峰值挠度,且偏心距和长细比越大,试件的柱中峰值挠度越大;达到极限荷载时,各偏压试件的侧向挠度曲线接近于正弦半波曲线。

Reinforced concrete(RC)bridge piers and columns located in strong saline soil and salt lake area in western China are suffering from corrosion attack,so a new type of composite column is proposed,which is herein referred to as steel reinforced polyethylene plastic pipe(SRPE)confined reinforced concrete column.Eight SRPE confined reinforced concrete columns and four unconfined control columns subjected to eccentric load were tested to study their mechanical properties.The failure pattern and load-axial displacement curves of specimens were obtained.The influence of design parameters such as pressure level of SRPE pipe,eccentricity and slenderness ratio on the mechanical properties of specimens was analyzed.The calculation formula of ultimate bearing capacity of SRPE pipe confined reinforced concrete columns subjected to eccentric load is also proposed for the actual application reference.The experimental results show that the ultimate bearing capacity and ductility of the RC columns under eccentric load are significantly improved for the confinement by SRPE pipe;The bearing capacity increases with the increase of pressure level of SRPE pipe,but the ductility is improved little.The bearing capacity decreases with the increase of eccentricity and slenderness ratio.The ductility of specimens decreases with the increase of slenderness ratio;The lateral peak deflection in the middle height of column confined by SRPE pipe is much larger than that of the control specimens,which increases with the increase of eccentricity and slenderness ratio;The lateral deflection corresponding to ultimate load is close to sine half-wave curve.