高温后钢管再生混凝土组合柱基本力学性能研究

发布时间：2018-08-04 13:30

【摘要】：我国每年都将产生大量的废旧混凝土，给生态环境带来了很大的负面影响。如何实现废旧混凝土的再生利用，对于生态、环境保护以及社会的可持续发展都具有紧迫的现实意义。再生混凝土是对废旧混凝土的再次利用，是将废旧混凝土经过破碎、清洗、分级之后作为骨料用于配制混凝土，再生混凝土与普通混凝土相比，其强度、弹性模量都低于相同配合比的普通混凝土，由此导致其力学性能、耐久性能、变形能力等都低于普通混凝土，这成了再生混凝土在结构工程中应用推广的最大障碍，目前再生混凝土在实际工程中的应用层次还比较低，主要用于非受力或者受力较小的结构中，如路基回填等，但再生混凝土与普通混凝土相比，具有升温滞后、耐高温性能好的优良特性，这种特性导致其在高温作用后力学性能丧失较少；同时由于钢材具有规则紧密的金相组织，导致其力学材性在高温作用后基本可以恢复。因此一些学者考虑将再生混凝土与钢管进行组合形成钢管再生混凝土组合构件，可有效提高构件高温作用后的力学性能，而且钢管对核心再生混凝土的“套箍”作用，可弥补再生混凝土力学性能差的缺陷。目前国内外针对钢管再生混凝土主要是常温下力学性能的研究，而对高温后的力学性能和工作机理的研究才刚刚起步，可参考的文献较少，因此，本文通过试验及有限元模拟对高温后钢管再生混凝土的力学性能及工作机理进行了探索，具体内容如下： 1.详细介绍了相关课题包括再生混凝土、钢管混凝土以及本课题钢管再生混凝土的特点、发展以及国内外研究现状，阐述了本文的研究方法、内容、目的及意义； 2.进行了17个高温后方钢管再生混凝土短柱和6个高温后圆钢管再生混凝土短柱的轴压试验，以考察不同温度、不同粗骨料取代率、不同截面形式对试件承载力的影响； 3.在确定了高温后钢材及再生混凝土的本构关系的基础上，通过ABAQUS建立与试验中试件参数相同的有限元模型，将ABAQUS计算结果与试验结果进行对比分析，验证了本文所建轴压模型的正确性，为了更全面的了解高温后钢管再生混凝土的力学性能，建立了与试验尺寸不同的轴压模型，分析了温度、取代率的影响，并进行了高温后钢管再生混凝土的受力性能及工作机理分析，最后在对大量数据进行回归分析之后，，推导出了高温后钢管再生混凝土短柱的轴压极限承载力的简化计算公式，并进行了验证； 4.使用有限元模拟软件ABAQUS建立高温后钢管再生混凝土偏压模型，首先建立与文献[44]中试验参数相同的偏压模型，并将模拟结果与其对比验证，验证了本文有限元模型的正确性。然后，建立与第三章中尺寸相同的偏压模型，对比分析了不同偏心率、温度、取代率、长细比对高温后钢管再生混凝土构件的影响规律，并进行了受力性能分析，最后通过对大量数据的回归分析，推导了高温后钢管再生混凝土短柱的偏压极限承载力简化计算公式，并进行了验证；
[Abstract]:Our country will produce a large amount of waste concrete every year, which has brought great negative influence on the ecological environment. How to realize the recycling of waste concrete has the urgent and realistic significance for the ecological, environmental protection and the sustainable development of the society. Recycled concrete is the reuse of waste concrete, and it is the waste concrete. After crushing, cleaning and grading, it is used as aggregate to make concrete. Compared with ordinary concrete, the strength and modulus of recycled concrete are lower than ordinary concrete with the same mix ratio. Thus, the mechanical properties, durability and deformability of recycled concrete are lower than ordinary concrete, which becomes the regenerated concrete in structural engineering. With the biggest obstacle of popularization, the application level of recycled concrete in actual engineering is still low, which is mainly used in non force or less stressed structures, such as subgrade backfilling, but regenerated concrete has the good characteristics of high temperature lag and high temperature resistance compared with ordinary concrete. This characteristic leads to the effect of high temperature. The mechanical properties of the steel have little loss. At the same time, the mechanical properties of the steel can be basically restored after the high temperature effect. Therefore, some scholars consider the combination of recycled concrete and steel pipe to form steel tube regenerative concrete components, which can effectively improve the mechanical properties of the components after the high temperature effect. The "hoop" effect of steel tube to the core recycled concrete can make up the defects of the poor mechanical properties of recycled concrete. At present, the research on the mechanical properties of recycled concrete is mainly at home and abroad, and the research on the mechanical properties and working mechanism after the high temperature has just started, and the references are less. Therefore, this paper passes through this paper. The mechanical properties and working mechanism of recycled concrete filled steel tube after high temperature are studied by experiment and finite element simulation.
1. the characteristics of recycled concrete, concrete-filled steel tube and steel tube recycled concrete are introduced in detail, and the development as well as the research status at home and abroad are introduced, and the research method, content, purpose and significance of this paper are expounded.
2. the axial compression tests of 17 short columns of recycled concrete filled steel tube and 6 short columns of recycled concrete filled steel tube after high temperature were carried out to investigate the influence of different temperature, different coarse aggregate substitution rate and different section forms on the bearing capacity of the specimens.
3. on the basis of determining the constitutive relation of steel and recycled concrete after high temperature, the finite element model with the same parameters as the test part is established by ABAQUS, and the results of ABAQUS calculation are compared with the test results. The correctness of the axial compression model is verified, and a more comprehensive understanding of the regenerated concrete of steel tube after high temperature is made. The axial pressure model with different test size was established, the influence of temperature and substitution rate was analyzed, and the mechanical properties and working mechanism of the steel tube recycled concrete were analyzed after high temperature. The ultimate bearing capacity of the steel tube regenerated concrete short column after high temperature was deduced after the regression analysis of a large number of data. The simplified formula is proved and verified.
4. the finite element simulation software ABAQUS is used to establish the eccentric compression model of steel tube recycled concrete after high temperature. First, the partial pressure model which is the same as the test parameters in literature [44] is established, and the simulation results are compared and verified, and the correctness of the finite element model is verified. Then, the bias model of the same size in the third chapter is established, and the comparison analysis is made. The effect of different eccentricity, temperature, substitution rate, length and length ratio on the steel tube regenerated concrete members after high temperature, and the analysis of the stress performance. Finally, the simplified calculation formula of the ultimate bearing capacity of the steel tube regenerated concrete short column after high temperature is deduced, and the calculation formula of the ultimate bearing capacity of the steel tube regenerated concrete short column is derived and verified.
【学位授予单位】：沈阳大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU398.9

【参考文献】