钢管自应力自密实高强混凝土短柱轴心受压承载力试验研究  

EXPERIMENTAL INVESTIGATION ON HIGH-STRENGTH SELF-STRESSING AND SELF-COMPACTING CONCRETE FILLED STEEL TUBE COLUMNS SUBJECTED TO UNIAXIAL COMPRESSION

作　　者：徐礼华[1] 吴敏[1] 周鹏华[1] 谷雨珊[1] 许明耀[1] XU Li-hua WU Min ZHOU Peng-hua GU Yu-shan XU Ming-yao(School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, Chin)

机构地区：[1]武汉大学土木建筑工程学院,湖北武汉430072

出　　处：《工程力学》2017年第3期93-100,共8页Engineering Mechanics

基　　金：国家自然科学基金项目(51478367)

摘　　要：为提高钢管内混凝土(Concrete Filled Steel Tube)的密实度,减小混凝土的收缩,以保证钢管与混凝土更好地共同工作,满足实际工程需要,该文提出采用钢管自应力自密实高强混凝土柱,考虑套箍指标、自应力、混凝土强度等因素,设计制作17根柱试件,通过静力试验研究其轴心受压性能。研究表明:在钢管内浇筑自应力高强混凝土,不但可以补偿混凝土的收缩,而且钢管的侧向约束可以明显改善高强混凝土的脆性;当套箍指标从0.548增加到0.846,柱承载力提高13%~21%;当混凝土强度由C60到C80,柱承载力提高5%~12%;自应力对柱承载力的影响呈二次抛物线分布;基于试验结果建立的钢管自应力自密实高强混凝土柱轴心受压承载力计算公式,可供实际工程参考。To improve the compactness and reduce the shrinkage of core concrete in concrete filled steel tube （CFST） columns, and to ensure a synergic action between steel and concrete to better fit practical needs, this paper deals with the mechanical behavior of high-strength self-stressing and self-compacting CFST columns under uniaxial compression. 17 column specimens were tested for different confining factors, self-stress levels and concrete strengths. The test results showed that the use of high-strength self-stressing and self-compacting concrete in CFST columns effectively compensated the shrinkage of core concrete, and the lateral constraints from steel tubes alleviated the brittleness of high strength concrete. In addition, the bearing capacity of the column was increased from 13% to 21% as the confining factor varied from 0.548 to 0.846, and was increased by 5% to 12% when the concrete strength upgraded from C60 to C80. The distribution of the self-stress versus the bearing capacity of the column followed a second-degree parabola. Based on the test result, analytical equations for the bearing capacity of the high-strength self-stressing and self-compacting CFST columns was developed, which is expected to serve as a reference for practical engineering applications.

关 键 词：钢管混凝土 自应力 自密实 轴压承载力 套箍系数 

分 类 号：TU398[建筑科学—结构工程]