偏心受压矩形钢管再生混合混凝土本构关系的试验研究

发布时间：2018-03-16 00:38

本文选题：偏心受压　切入点：矩形钢管　出处：《华侨大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着我国城市化进程的持续推进,建筑垃圾与日俱增,其中工程废弃混凝土约占建筑垃圾的48.35%,如何绿色环保的处理这些废弃混凝土成为了亟待解决的环境问题。将废弃混凝土破碎筛分后用于再生混凝土是目前较为常见的一种处理方法之一,但再生混凝土强度及弹性模量低、收缩徐变大、流动性差等缺点严重阻碍其推广应用。为解决此矛盾,本课题组引入薄壁钢管-再生混合混凝土的研究,该结构能充分发挥各自材料的优势,强度高、塑性好、施工速度快,同时免去了再生骨料筛分、净化等繁琐程序,节省了大量的资金和能源。本文选用ANSYS有限元模拟与试验相对比的方法,探讨偏心荷载作用下矩形钢管再生混合砼的本构关系。选取偏心率、高宽比、含钢率、混合比为变量,设计23个偏压试件和3个轴压试件进行试验研究。研究结果表明:(1)矩形钢管再生混合砼短柱在偏心荷载作用下展现较好的力学性能,破坏形态以腰鼓形破坏为主,有少量试件出现剪切破坏;(2)对于本文试验构件的极限承载力,偏心率越大,极限承载力越小,含钢率越大,极限承载力越大,而高宽比和混合比对承载力的影响有限;(3)影响偏压矩形钢管再生混合混凝土短柱延性的主要因素是偏心率和高宽比,偏心率大的试件变形性能更好,高宽比越大,试件延性越差,含钢率和混合比对试件延性的影响有限。结合理论研究与试验数据回归分析,提出偏心率对紧箍力影响的修正系数,将该系数应用于课题组已有本构关系,得到适用于偏心受压矩形钢管再生混合混凝土的应力-应变关系模型,采用修正后的模型进行有限元计算,发现计算结果与试验结果吻合良好。选用国内外典型规范(程)CECS159:2004、DBJ13-51-2003、ACI318-11、AIJ-1997、BS5400-2005、EC4-2004计算偏心受压矩形钢管再生混合混凝土短柱极限承载力。根据福建省地方标准DBJ计算所得数据和试验数据最为接近,且数据波动性较小,建议选用上述规程计算矩形钢管再生混合短柱在偏心荷载作用下的极限承载力。最后结合理论研究和试验数据回归分析,给出了矩形钢管再生混合短柱在偏心荷载作用下的极限承载力简化计算式。
[Abstract]:With the continuous development of urbanization in China, construction waste is increasing day by day. Engineering waste concrete accounts for about 48.35% of construction waste. How to deal with the waste concrete green has become an urgent environmental problem. One of the ways to deal with, However, the shortcomings of recycled concrete, such as low strength and elastic modulus, large shrinkage and creep, poor fluidity and so on, seriously hinder its popularization and application. In order to solve this contradiction, this paper introduces the research of thin-walled steel tube-recycled mixed concrete. The structure can give full play to the advantages of their respective materials, high strength, good plasticity, fast construction speed, and at the same time, it eliminates the tedious procedures such as screening and purification of recycled aggregate. In this paper, the constitutive relation of recycled concrete of rectangular steel tube under eccentric load is discussed by using ANSYS finite element simulation and experimental method. The eccentricity ratio, aspect ratio, steel content ratio and mixing ratio are selected as variables. Twenty-three eccentric compression specimens and three axial compression specimens were designed for experimental study. The results show that the recycled concrete short columns of rectangular steel tubes exhibit better mechanical properties under eccentric loading, and the failure mode is mainly waist drum failure. For the ultimate bearing capacity of the tested members, the greater the eccentricity, the smaller the ultimate bearing capacity, the greater the steel content, the greater the ultimate bearing capacity. However, the influence of aspect ratio and mixing ratio on the bearing capacity is limited.) the main factors affecting ductility of rectangular steel tube regenerated concrete short columns are eccentricity and ratio of height to width. The specimen with large eccentricity has better deformation performance and higher aspect ratio. The worse the ductility of the specimen, the less the influence of the steel content and the mixing ratio on the ductility of the specimen. Combined with the regression analysis of theoretical research and experimental data, the modified coefficient of the influence of eccentricity on the hoop force is put forward, which has been applied to the constitutive relation of the research group. The stress-strain relationship model for recycled concrete filled rectangular steel tubes under eccentric compression is obtained. The modified model is used to calculate the stress-strain relationship. It is found that the calculated results are in good agreement with the test results. The ultimate bearing capacity of recycled concrete filled rectangular steel tubes with eccentrically compressed rectangular steel tubes is calculated according to the local standard DBJ of Fujian Province, and the ultimate bearing capacity of recycled concrete columns of rectangular steel tubes under eccentric compression is calculated according to the typical domestic and foreign codes (CCECS159: 2004DJ13-51-20033-2003) and AIJ-1997 / BS5400-2005 / EC4-2004. The test data are closest, It is suggested that the above rules be used to calculate the ultimate bearing capacity of rectangular steel tube regenerated mixed short columns under eccentricity load. Finally, combined with theoretical research and experimental data regression analysis, A simplified formula for calculating the ultimate bearing capacity of rectangular steel tube regenerated mixed short columns under eccentric load is presented.
【学位授予单位】：华侨大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU398.9

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