再生骨料物理性质对再生保温混凝土力学性能的影响研究

发布时间：2018-05-18 23:18

本文选题：再生保温混凝土 + 再生骨料物理性质　；参考：《太原理工大学》2017年硕士论文

【摘要】：再生保温混凝土的研究对我国实现资源综合利用与节能减排具有重要的推动作用,但再生骨料来源复杂,离散性较大,这限制了再生保温混凝土的推广应用。另外,再生保温混凝土受再生骨料、保温骨料的双重影响,其内部含有多种界面结构,破坏时的内部损伤产生部位随机性大,因此如何建立这一类内部含多种界面结构的混凝土随机损伤模型,具有重要的理论意义。针对此背景,本文侧重于研究再生骨料物理性质对再生保温混凝土基本力学的影响规律,通过应力-应变试验回归得到再生保温混凝土应力-应变关系方程,并在此基础上,建立再生保温混凝土受压随机损伤本构模型,揭示再生保温混凝土单轴受压破坏机理。本文主要工作及主要结论:1.研究了不同再生骨料级配、不同再生骨料原生强度、不同再生骨料初始含水率对再生保温混凝土工作性能的影响,结果表明:再生保温混凝土的初始坍落度随骨料粒径的增大而增加,而骨料原生强度和含水率对其初始坍落度影响不明显,但再生骨料含水率对经时坍落度影响较大:随着时间的增长,再生骨料含水率为0%时,混凝土坍落度急剧减小,30min可损失76.7%;而含水率为100%时,30min坍落度损失仅为37.6%。2.研究了上述三种因素对再生保温混凝土基本力学性能的影响,研究表明,A/B=3/7时的再生粗骨料制备的再生保温混凝土强度最低,级配调整后可增加立方体抗压强度,当级配A/B=2/8时强度最大,提高了27.3%。再生骨料原生强度越高,所配制的再生保温混凝土强度越高。随着再生骨料初始含水率的增加,再生保温混凝土强度逐渐降低。与普通混凝土相比,再生保温混凝土弹性模量较低。弹性模量与强度的变化规律基本一致,但不同再生骨料级配对混凝土弹性模量影响不明显,混凝土弹性模量介于2.36×104mpa~2.42×104mpa之间。再生保温混凝土弹性模量随着再生骨料原生强度的提高而增加,随再生骨料初始含水率的增加而降低。通过对三种不同因素下再生保温混凝土强度的分析,得到了立方体抗压强度与轴心抗压强度关系,即fc/fcu=0.93。3.在应力-应变关系方面,主要的工作及结论为:第一,再生保温混凝土的峰值应变大于同强度普通混凝土,不同再生骨料级配下的再生保温混凝土峰值应变在0.002307~0.002863之间,不同再生骨料原生强度下的再生保温混凝土峰值应变在0.002080~0.002399之间,不同再生骨料初始含水率下的再生保温混凝土峰值应变在0.001647~0.002340之间;第二,再生保温混凝土极限应变与峰值应变的比值随粗骨料粒径增加而增加,随骨料原生强度的增加而降低,而再生骨料初始含水率的大小对其影响不明显,再生保温混凝土延性比普通混凝土好;第三,以试验数据为基础,回归分析了再生保温混凝土单轴受压本构方程,拟合曲线与试验数据拟合度较高;第四,考虑到再生保温混凝土组成材料物理性能的差异性以及再生骨料本身的随机性,对再生保温混凝土在细观尺度上进行了划分,建立了再生保温混凝土细观破坏弹簧模型,该模型不仅仅适用于再生保温混凝土这一种材料,同样适用于内部含多种界面结构的其他材料;另外,在细观弹簧模型的基础上,推导了再生保温混凝土随机损伤本构方程。受压随机损伤本构方程与试验点、应力-应变曲线拟合方程吻合度较高。
[Abstract]:The research on recycled thermal insulation concrete plays an important role in promoting the comprehensive utilization of resources and energy saving and emission reduction in China. However, the recycled aggregate is complex and large, which restricts the popularization and application of recycled thermal insulation concrete. In addition, recycled aggregate concrete is affected by recycled aggregate and thermal insulation, which contains a variety of interfaces. It is of great theoretical significance how to establish a random damage model of concrete with multiple interface structures in this kind of structure. This paper focuses on the study of the effect of the physical properties of recycled aggregate on the basic mechanics of recycled thermal insulation concrete. The stress-strain relation equation of recycled thermal insulation concrete was regressed by variable test. On this basis, the constitutive model of recycled thermal insulation concrete was established to reveal the single axial compression failure mechanism of recycled thermal insulation concrete. The main work and main conclusions are as follows: 1. the primary strength of recycled aggregate is studied, and the primary strength of recycled aggregate is studied. The effect of the initial water content of recycled aggregate on the performance of regenerated thermal insulation concrete shows that the initial slump of recycled concrete increases with the increase of aggregate particle size, while the primary strength and water content of aggregate have no obvious effect on its initial slump, but the water content of recycled aggregate has a great influence on the slump degree: with the time of time, the water content of recycled aggregate has a great influence on the slump When the water content of recycled aggregate is 0%, the slump of concrete decreases sharply and 30min can lose 76.7%. When the water content is 100%, the 30min slump loss is only 37.6%.2., and the effect of the above three factors on the basic mechanical properties of the recycled concrete is studied. The study shows that the recycled coarse aggregate prepared by the regenerated aggregate at A/B=3/7 The soil strength is the lowest, and the compressive strength of the cube can be increased after the gradation is adjusted. The strength of the recycled aggregate concrete is higher when the gradation of A/B=2/8 is maximum. The higher the original strength of the recycled aggregate 27.3%. is, the higher the strength of the regenerated thermal insulation concrete. The elastic modulus of the raw concrete is low. The elastic modulus of the elastic modulus and the strength of the concrete are basically the same, but the elastic modulus of concrete with different recycled aggregate grades is not obvious, and the elastic modulus of concrete is between 2.36 * 104mpa~2.42 * 104mpa. The relationship between the compressive strength of the cube and the axial compression strength is obtained by the analysis of the strength of the recycled concrete under three different factors. The main work and conclusion are as follows: first, the peak strain of the recycled thermal insulation concrete is greater than that of the same fc/fcu=0.93.3.. The peak strain of recycled thermal insulation concrete under different recycled aggregate gradation is 0.002307~0.002863, and the peak strain of recycled thermal insulation concrete under the original strength of recycled aggregate is 0.002080~0.002399, and the peak strain of recycled thermal insulation concrete under the initial water content of recycled aggregate is 0.001647~0.00234 0, second, the ratio of the ultimate strain to the peak strain of recycled concrete increases with the increase of coarse aggregate size, and decreases with the increase of aggregate primary strength, but the initial water content of recycled aggregate is not obvious. The ductility of recycled aggregate concrete is better than that of ordinary concrete; third, based on the test data, the regression score is based on the test data. The uniaxial compression constitutive equation of recycled thermal insulation concrete is analyzed. The fitting curve of the fitting curve is higher than the test data. Fourth, considering the difference of physical properties and the randomness of recycled aggregate, the regenerated thermal insulation concrete is divided on the meso scale, and the meso of recycled thermal insulation concrete is set up. The model of failure spring is not only suitable for the material of recycled thermal insulation concrete, but also suitable for other materials with various interface structures. On the basis of the mesoscopic spring model, the constitutive equation of the random damage of recycled concrete is derived. The constitutive equation and the test point and the stress-strain curve of the compression random damage are derived. The fitting equation has a high degree of anastomosis.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

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