多轴压应力下再生混凝土动态力学性能研究

发布时间：2018-06-29 18:56

本文选题：再生混凝土 + 多轴压　；参考：《北方工业大学》2017年硕士论文

【摘要】：再生混凝土技术实现了废弃混凝土的再利用,既节约了资源又对环境保护起到了积极的作用。实际的混凝土结构中混凝土大都处于多轴应力状态,研究混凝土在复杂应力下的力学性能,对于这类结构的合理设计、安全运行和节省建筑材料有着重大意义。混凝土结构在使用过程中易受到地震、冲击等动态荷载作用,对不同应变速率下再生混凝土力学性能的研究,可以为该类结构的抗震设计提供依据。基于上述分析,本文主要进行了以下研究:1.进行了 5种再生混凝土在4个应变速率等级下的单轴拉、压试验,对再生混凝土在单轴受压下的试验现象和破坏形态、试验结果及强度规律进行描述和分析。建立了再生混凝土单轴压强度与应变速率间的关系式,并根据关系式中参数的规律对该关系式进行了简化,简化后的单轴压动态强度关系可以作为不同强度等级下替代率为30%和50%的再生混凝土单轴压动态强度计算式。通过对试验实测数据的分析处理,给出再生混凝土试件单轴压应力应变曲线。2.进行了 5种再生混凝土在4个应变速率等级下的双轴压试验,对再生混凝土在双轴受压下的试验现象和破坏形态、试验结果及强度规律进行描述和分析,研究不同应变速率、不同应力比对再生混凝土双轴强度的影响,建立了再生混凝土动态双轴压破坏准则,该破坏准则适用于本次试验中的5种再生混凝土材料,在给定再生混凝土材料后即可计算任意应力比和任意应变速率下的双轴压破坏强度。通过对试验实测数据的分析处理,给出再生混凝土试件双轴压应力应变曲线。3.进行了 5种再生混凝土在4个应变速率等级下的三轴压试验,对再生混凝土在三轴受压下的试验现象和破坏形态进行描述,给出再生混凝土三轴受压试验结果,研究应变速率、应力比对再生混凝土三轴压强度的影响。在本人导师以往研究的基础上,对再生混凝土三轴破坏准则在不同应变速率下的参数进行回归分析,建立了含有应变速率参数的再生混凝土三轴破坏准则。通过对试验实测数据的分析处理,给出再生混凝土试件三轴压应力应变曲线。
[Abstract]:Recycled concrete technology realizes the reuse of waste concrete, which not only saves resources but also plays an active role in environmental protection. In practical concrete structures, the concrete is mostly in the state of multiaxial stress. It is of great significance to study the mechanical properties of concrete under complex stress for the rational design, safe operation and saving of building materials of this kind of structures. Concrete structures are easily subjected to dynamic loads such as earthquake and impact during use. The study on the mechanical properties of recycled concrete under different strain rates can provide a basis for the seismic design of this kind of structures. Based on the above analysis, this paper mainly carries out the following research: 1. The uniaxial tension and compression tests of five kinds of recycled concrete under four strain rate grades were carried out. The experimental phenomena and failure patterns of recycled concrete under uniaxial compression were described and analyzed. The relationship between uniaxial compressive strength and strain rate of recycled concrete is established and simplified according to the law of parameters in the formula. The simplified dynamic strength relationship of uniaxial compression can be used as a formula for calculating the dynamic strength of recycled concrete under uniaxial compression with substitution rates of 30% and 50% under different strength grades. The uniaxial compressive stress-strain curve of recycled concrete specimen is given by analyzing and processing the measured data. The biaxial compression tests of five kinds of recycled concrete under four strain rate grades were carried out. The experimental phenomena and failure patterns of recycled concrete under biaxial compression, the test results and the strength law were described and analyzed, and the different strain rates were studied. The dynamic biaxial compression failure criterion of recycled concrete is established by the influence of different stress ratios on biaxial strength of recycled concrete. The failure criterion is applicable to five kinds of recycled concrete materials in this experiment. The biaxial compressive failure strength under arbitrary stress ratio and strain rate can be calculated when the recycled concrete material is given. The biaxial compressive stress-strain curve of recycled concrete specimen is given by analyzing and processing the measured data. The triaxial compression tests of five kinds of recycled concrete under four strain rate grades were carried out. The experimental phenomena and failure patterns of recycled concrete under triaxial compression were described, and the results of triaxial compression tests of recycled concrete were given. The effect of strain rate and stress ratio on triaxial compressive strength of recycled concrete is studied. On the basis of previous research by my tutor, the parameters of recycled concrete triaxial failure criterion under different strain rates are regressed and the triaxial failure criterion of recycled concrete with strain rate parameters is established. Through the analysis and processing of the measured data, the triaxial compressive stress-strain curves of recycled concrete specimens are given.
【学位授予单位】：北方工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

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