500 MPa级钢筋自密实混凝土偏压短柱受力性能试验及有限元模拟分析

通过对7根500 MPa级钢筋自密实混凝土短柱试件的偏心受压试验，研究了试件的受力特征以及高强钢筋与自密实混凝土之间的协同工作性能。试验结果表明，500 MPa级钢筋在柱中与自密实混凝土协同工作性能良好，试件在偏心受压全过程中基本符合平截面假定。采用ABAQUS软件，建立500 MPa级钢筋自密实混凝土偏压短柱的有限元模型，利用试验实测结果验证模型的适用性与可靠度，并分析自密实混凝土强度、初始荷载偏心距和纵筋配筋率对偏心受压短柱力学性能的影响规律。试验实测值与有限元模拟分析结果表明，500MPa级钢筋自密实混凝土偏压短柱正截面受压承载力可采用《公路钢筋混凝土及预应力混凝土桥涵设计规范》（JTG D62-2004）中的相关公式计算；为保证一定的安全储备，建议500 MPa级钢筋的设计强度取值为f_sd=f_sd'=420 MPa，材料分项系数取值为γ_s=1.2。

EXPERIMENTAL AND NUMERICAL ANALYSIS ON MECHANICAL BEHAVIOR OF ECCENTRICALLY LOADED SELF-COMPACTING CONCRETE SHORT COLUMNS WITH 500 MPa STEEL BARS

Seven self-compacting concrete short column specimens with 500 MPa reinforced bars were tested under eccentric compression load to investigate the mechanical behaviors and the co-working performance between high-strength steel bars and self-compacting concrete. The experimental results indicate that the 500 MPa steel bars can work well with self-compacting concrete, and the average axial strains of the specimens basically agree with the assumption of plane section under the whole process of eccentric compression loading. Finite element (FE) models for the eccentrically compressed short columns were built by ABAQUS software, and the FE models were verified by the test results. Furthermore, numerical analysis was carried out to study the influence of strength of self-compacting concrete, initial eccentricity and ratio of longitudinal reinforcement. The results show that normal section bearing capacities of eccentrically compressed self-compacting concrete short columns with 500 MPa reinforced bars can be calculated according to the current Chinese code. Moreover, the design strength of 500 MPa steel bars are suggested as f_sd=f_sd'=420 MPa, and partial coefficient of the material is suggested as γ_s=1.2.