Flexural Performance of High-strength Prestressed Concrete-encased Concrete-filled Steel Tube Sections
Flexural Performance of High-strength Prestressed Concrete-encased Concrete-filled Steel Tube Sections
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DOI：
10.5829/ije.2019.32.09c.03
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发表时间：
2019-09
影响因子：
1.3
通讯作者：
Z. Rahmani;M. Naghipour;M. Nematzadeh
中科院分区：
文献类型：
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作者：
Z. Rahmani;M. Naghipour;M. Nematzadeh
由混凝土和钢组成的截面，包括外包式钢管混凝土，由于混凝土的抗拉强度较低，通常存在缺陷。为此，采用了合适的方法将钢管混凝土与包裹在混凝土中的预应力钢绞线结合在一起。常规的设计准则通常是针对普通强度的材料制定的，因此需要对高强度材料的截面进行进一步的研究。为了开发设计过程，本研究采用高强混凝土和钢筋，研究了钢和混凝土强度对高强预应力钢管混凝土(HS-PCE-CFST)梁的核心混凝土约束、截面尺寸和受弯性能的影响。因此，利用ABAQUS有限元软件对13根HS-PCE-CFST梁进行了有限元模拟。主要变量包括核心和外层混凝土的钢管屈服强度、受压圆筒强度和钢管直径与截面宽比。并利用试验结果对有限元模型进行了验证。分析了梁的弯矩、延性、抗弯刚度和破坏模式。结果表明，在核心混凝土和外层混凝土的抗压强度和钢管屈服强度中，外层混凝土抗压强度的变化对抗弯参数的变化影响较大，增大钢管直径与截面宽度之比对极限弯矩和正常使用水平的抗弯刚度影响不大，而对初始抗弯刚度的影响较大。
The sections composed of concrete and steel, which include concrete-encased concrete-filled tubes, generally have defects due to the low tensile strength of concrete. Therefore, an appropriate method was used for the combination of concrete-filled tubes (CFT) and prestressing strands which is encased in concrete. The conventional design guidelines are commonly developed for materials with normal strength thus further investigation is required to be conducted for sections with high-strength materials. In order to develop the design process, high-strength concrete and steel have been utilized in this study to examine the effects of steel and concrete strengths on the core concrete confinement, sectional size and flexural behavior of high-strength prestressed concrete-encased CFST (HS-PCE-CFST) beams. Hence, a total of thirteen HS-PCE-CFST beams were modeled via ABAQUS finite element software. The main variables include the steel tube yield strength, compressive cylinder strength of the core and outer concrete and the steel tube diameter to section width ratio. Furthermore, experimental results were employed to verify the finite element model. The bending moment, ductility, flexural stiffness and failure mode of beams are also examined. The results confirm that among the compressive strength of the outer and core concrete and the steel tube yield strength, change in the outer concrete compressive strength has a greater effect on the change of flexural parameters, also increasing the ratio of steel tube diameter to section width causes a minor increase in the ultimate bending moment and serviceability level flexural stiffness, but a major escalation in the initial flexural stiffness.