方钢管自密实混凝土加固钢筋混凝土方形截面短柱轴压性能试验研究

文章编号：1000-6869（2015）07-0043-08DOI：10．14006/j．jzjgxb．2015．07．006方钢管自密实混凝土加固钢筋混凝土方形截面

短柱轴压性能试验研究

卢亦焱，梁鸿骏，李杉，殷晓三

（武汉大学土木建筑工程学院，湖北武汉430072）

摘要：提出外套方钢管自密实混凝土加固钢筋混凝土方形截面柱的复合加固方法。通过对8根加固柱试件（其中1根为增大截面法加固钢筋混凝土方形截面柱试件、7根为复合加固法加固钢筋混凝土方形截面柱试件）和2根未加固钢筋混凝土方形截面柱试件进行轴心受压试验，研究不同加固方法、钢管壁厚、后浇自密实混凝土强度和加载方式对加固柱力学性能的影响。结果表明：采用外套方钢管自密实混凝土复合加固法能显著提高原柱的承载力和延性；在用钢量基本相同的情况下，复合加固柱试件的承载力和延性均高于增大截面法加固柱试件；随着钢管壁厚的增大，复合加固柱试件的承载力和延性都显著增大；随着后浇混凝土强度的提高，复合加固柱试件的承载力有所增大，但延性显著下降；采用钢管与混凝土全截面受压加载方式的复合加固柱试件的延性和承载力略小于仅混凝土受压加载方式和上端仅混凝土受压、下端全截面受压加载方式的复合加固柱试件。在试验研究的基础上，建立了外套方钢管自密实混凝土复合加固钢筋混凝土方形截面短柱轴压承载力计算式，计算结果与试验结果吻合良好。

关键词：钢筋混凝土方形截面柱；自密实混凝土；方钢管；复合加固法；静力试验；轴压性能

中图分类号：TU398．902TU317．1文献标志码：A

Experimental study on behavior of squareＲC columns strengthened with self-compacting concrete filled

square steel tubes under axial load

LU Yiyan，LIANG Hongjun，LI Shan，YIN Xiaosan

（School of Civil Engineering，Wuhan University，Wuhan430072，China）

Abstract：A new composite strengthening method whichＲC column is strengthened with self-compacting concrete filled square steel tubes is presented．To study the influences of different strengthening methods，wall thickness of steel tube，compressive strength of self-compacting concrete and loading modes on the mechanical property of two unstrengthenedＲC columns，oneＲC column strengthened with enlarging cross-section method and sevenＲC composite strengthened columns were tested under axial load．The results show that the composite strengthening method significantly improves the ultimate bearing capacity and ductility of the original columns．And the bearing capacity and ductility of the composite strengthened columns are significantly better than the columns strengthened with enlarging cross-section in case of the almost same steel consumption．With the wall thickness of steel tube increasing，the bearing capacity and ductility of the composite strengthened columns significantly increase．With the compressive strength of strengthening concrete increasing，the bearing capacity slightly increases while the ductility significantly decreases．The ultimate bearing capacity and ductility of composite strengthened columns which were loaded on the full section are less than the others．On the basis of the experiments，a simple formula is proposed to calculate the bearing capacity of the composite strengthened columns，and the calculation results agree well with the experimental results．Keywords：squareＲC column；self-compacting concrete；square steel tube；composite strengthening method；static test；axial compression

基金项目：国家自然科学基金项目（51078294），中央高校基本科研业务费专项（2014210020201）。

作者简介：卢亦焱（1965—），男，福建永定人，工学博士，教授。E-mail：yylu901@163．com

收稿日期：2014年5月