SRPE套管钢筋混凝土短柱轴压承载力试验研究

Experimental research on the bearing capacity of SRPE pipe reinforced concrete circular columns under axial compression

针对西部强盐渍土/盐湖地区的钢筋混凝土桥梁墩柱的严重腐蚀问题,本文提出新材料组合结构“钢骨架聚乙烯塑料复合管(SRPE)约束钢筋混凝土柱”。为研究其轴心受压承载力力学性能,进行了12根SRPE套管钢筋混凝土短柱和2根无套管钢筋混凝土短柱的轴心受压试验,获得了试件破坏形态和荷载-应变曲线,进而分析了SRPE管公称压力等级、混凝土强度等级、体积配箍率(指按核心混凝土中的箍筋计算)等因素对试件轴压承载力的影响规律,并给出了SRPE套管钢筋混凝土短柱的轴压承载力计算公式,为工程应用提供参考。研究结果表明:SRPE套管可以显著提高试件的承载力和峰值位移,承载力和峰值位移随SRPE管压力等级的提高近似呈线性提高;随着混凝土强度等级的提高,试件的承载力越高但峰值位移越小;随着混凝土强度等级的提高,试件的承载力和峰值位移的提高效果下降;随着体积配箍率的增大,试件的承载力越大,但对提高试件的峰值位移不明显。

In view of serious corrosion of reinforced concrete bridge pier columns in strong saline soil/salt lake area in the west, a new composite structure “steel reinforced polyethylene plastic composite pipe(SRPE) restrained reinforced concrete column” is proposed in this paper. In order to study the mechanical properties of bearing capacity under axial compression, axial compression tests are carried out on 12 SRPE casing reinforced concrete short columns and 2 non-casing reinforced concrete short columns, and the destruction form and load-strain curves of specimens are obtained. The influence laws of nominal pressure grade of SRPE tube, strength grade of concrete and volume stirrup ratio(refers to the calculation of stirrups in core concrete) on the axial compression bearing capacity of specimens are analyzed, and the calculation formula of axial bearing capacity of SRPE tube reinforced concrete short column are presented, which can provide reference for engineering application.The results show that: SRPE casing can significantly improve the bearing capacity and peak displacement of specimens, and the bearing capacity and peak displacement increase linearly with the increase of SRPE pipe pressure grade;With the improvement of concrete strength grade, the higher the bearing capacity of specimens is, the smaller the peak displacement is;With the improvement of concrete strength grade, the improvement effect of bearing capacity and peak displacement decreases;With the increase of volume stirrup ratio, the bearing capacity of the specimen increases, but the peak displacement of the specimen does not increase obviously.