【摘要】 为提高钢管内混凝土的密实度,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,考虑偏心距、长径比和初始自应力等参数的影响,设计制作21根钢管自应力自密实高强混凝土柱和3根钢管自密实高强混凝土柱试件,通过偏心受压试验,考察试件的破坏形态,实测试件的荷载-挠度曲线和荷载-应变曲线,分析各参数对偏心受压试件受力性能的影响。研究表明:偏心受压试件主要发生弯曲失稳破坏;试件极限承载力随偏心距或长径比增大而减小,当初始自应力为3 MPa~5 MPa时,钢管自应力自密实混凝土偏心受压柱的极限承载力提高9.2%~11.7%。参考国内相关规范,通过试验数据回归分析,提出钢管自应力自密实高强混凝土柱偏心受压承载力计算公式,可供工程设计参考。更多还原

【Abstract】 In order to improve the compactness of core concrete fills in steel tubes and reduce shrinkage which can ensure better composite action and meet project needs, twenty-one self-stressing self-compacting and high-strength concrete filled steel tubular columns and three self-compacting and high-strength concrete filled steel tubular columns were designed and tested under eccentric compression. The factors influencing the failure mode of specimens, namely slenderness ratio, eccentricity ratio and initial self-stressing, were investigated. The load-strain curves and load-column deflection curves were analyzed. The results showed that the eccentrically compressed specimens mainly demonstrate flexible buckling failure; the ultimate bearing capacity of the specimen decreases with the increase in load eccentricity ratio and slenderness ratio. The ultimate bearing capacity of the self-stressing and self-compacting concrete filled steel tubular columns can be improved by 9.2%~11.7% with initial self-stressing ranging between 3 to 5 MPa. Based on the relevant domestic design codes, a predictive equation for the ultimate bearing capacity of self-stressing self-compacting and high-strength concrete filled steel tubular columns was derived through regression analysis, and can serve as a reference for practical engineering design.更多还原