钢管高强机制砂混凝土粘结性能试验研究

发布时间：2018-03-30 18:32

本文选题：钢管高强机制砂混凝土　切入点：粘结机理　出处：《深圳大学》2017年硕士论文

【摘要】：钢管混凝土结构具有承载能力高、变形和耗能能力强的优点,由其建造的高层建筑经济效果好,已成为工程应用中广泛采用的建筑结构形式。但工程上所用的砂基本为天然砂,但天然砂是一种不可再生资源,日益面临枯竭,因此,急需寻求一种新的砂源来代替。利用岩石资源或工程弃置的废石生产机制砂,可部分或全部替代天然砂制备混凝土,并可与钢管组合形成钢管高强机制砂混凝土结构。本文制作了54根钢管高强机制砂混凝土试件,采用推出试验方法研究钢管与机制砂混凝土界面粘结机理、粘结应力以及沿构件纵向相对滑移的分布,并考虑机制砂的原料形态(石灰石、卵石)、混凝土强度、石粉含量、径厚比等因素对钢管机制砂混凝土界面粘结性能的影响。在此基础上,提出了钢管与高强机制砂混凝土粘结-滑移本构关系。主要研究内容如下:(1)通过钢管高强机制砂混凝土试件推出试验,可以得到各试件的荷载-滑移曲线,分析和归纳曲线特征,得到其典型的荷载-滑移曲线。研究发现机制砂原料形态对荷载-滑移曲线形状影响较大:机制砂原料形态为石灰石的试件,其P-S曲线经峰值点后发展比较平缓,无明显的下降段;而原料形态为卵石的试件的P-S曲线在经过峰值点后,出现了明显的下降段。(2)通过在钢管纵向不同位置连续布置位移计和电阻应变片,测出钢管应变和滑移在整个推出试验过程中沿钢管高度方向的变化规律,并依据钢管混凝土界面粘结力与钢管应变微分成正比关系,得出粘结应力的的大小及分布规律。(3)研究了机制砂原料形态、石粉含量、混凝土强度、径厚比等因素对钢管机制砂混凝土界面粘结力的影响以及粘结强度变化规律。(4)通过对试件平均粘结应力-自由端滑移曲线的分析,提出了平均粘结应力-自由端滑移本构模型,经过与试验结果进行对比,发现二者吻合较好,从而验证了其合理性。在此基础上,以平均粘结应力-自由端滑移曲线为基准曲线,进一步提出了考虑位置变化的粘结—滑移本构关系。
[Abstract]:Concrete-filled steel tube (CFST) structure has the advantages of high bearing capacity, strong deformation and energy dissipation capacity. The high-rise building built by it has good economic effect and has become a widely used structural form in engineering applications. However, the sand used in engineering is basically natural sand. However, natural sand is a kind of non-renewable resource, which is facing depletion day by day. Therefore, it is urgent to find a new sand source to replace it. In this paper, 54 specimens of steel tube high strength machined sand concrete are made, and the interfacial bond mechanism between steel tube and machined sand concrete is studied by deducing test method. The distribution of bond stress and relative slippage along the longitudinal direction of the member, and taking into account the raw material form of the machine-made sand (limestone, pebbles, concrete strength, stone powder content, etc.). The influence of diameter to thickness ratio on the interfacial bond behavior of steel tube machine-made sand concrete. The bond-slip constitutive relation between steel tube and high-strength machined sand concrete is proposed. The main research contents are as follows: (1) the load-slip curves of each specimen can be obtained by deducing the test piece of high-strength machined sand concrete of steel tube. The characteristic of the curve is analyzed and summarized, and the typical load-slip curve is obtained. It is found that the shape of the machine-made sand has a great influence on the shape of the load-slip curve: the raw material form of the machine-made sand is the sample of limestone. The P-S curve developed slowly after the peak point, and the P-S curve of the sample with the pebble shape passed through the peak point. A significant descending section appears. (2) through the continuous placement of displacement meters and resistance strain gauges at different longitudinal positions of the steel tube, the variation of the strain and slippage of the steel tube along the direction of the height of the steel pipe during the whole roll-out test is measured. According to the relationship between the interface bond force of CFST and the strain of steel tube, the size and distribution of bond stress are obtained. The material form of machine-made sand, the content of stone powder and the strength of concrete are studied. The influence of diameter to thickness ratio on the interfacial bond force of steel tube machined sand concrete and the change rule of bond strength. (4) based on the analysis of the average bond stress-free end slip curve of the specimen, an average bond stress-free end slip constitutive model is proposed. By comparing with the experimental results, it is found that the two are in good agreement with each other, and the rationality is verified. On this basis, the average bond stress-free end slip curve is taken as the reference curve. Furthermore, a bond-slip constitutive relation considering the change of position is proposed.
【学位授予单位】：深圳大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

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