钢管再生混凝土长柱偏压性能研究

STUDY ON ECCENTRIC COMPRESSION BEHAVIORS OF RECYCLED AGGREGATE CONCRETE FILLED STEEL TUBULAR LONG COLUMNS

对10个圆钢管再生混凝土和10个方钢管再生混凝土长柱进行偏压静力单调加载试验,考虑了再生粗骨料取代率、长细比、偏心距3个变化参数,观察了试件受力的全过程和试件破坏形态,绘制出荷载-变形、荷载-应变等一系列重要关系曲线,给出了截面应变沿高度分布情况,并分析了变化参数对试件极限承载力的影响规律,采用国内外常用的8部相关规程计算两种截面形式试件的极限承载力。研究结果表明:钢管再生混凝土偏压长柱受力过程均经历了弹性阶段、屈服阶段和破坏阶段,破坏形态主要为弹塑性失稳破坏;建议采用规程DL/T5085-1999和DBJ13-51-2003设计圆钢管再生混凝土偏压长柱试件的极限承载力,采用规程CECS159:2004、DBJ13-51-2003设计方钢管再生混凝土偏压长柱试件的极限承载力。

Eccentric compression static monotonic loading test was carried out on 10 recycled aggregate concrete（RAC） filled cycled steel tubular long columns and 10 RAC filled square steel tubular long columns. The changing parameters including replacement rate of recycled coarse aggregate, slenderness ratio and eccentricity were considered. The whole force process and failure modes were observed, while important curves about load-deformation and load-strain were drawn, while strain distribution along cross section height was made. The influence of the changing parameters on the ultimate bearing capacity was analyzed, while the ultimate bearing capacity of two section types was calculated by 8 related procedures. It is shown that force process is made up of elastic stage, yield stage and destruction stage, while failure modes are mainly destruction of elastic-plastic instability. It is suggested that the ultimate bearing capacity of RAC filled cycled steel tubular long columns under eccentric compression can be designed using DL/T 5085-1999 and DBJ13-51-2003, while RAC filled square steel tubular can be designed using CECS 159：2004 and DBJ13-51-2003.