再生保温混凝土力学性能尺寸效应研究

发布时间：2018-03-07 09:48

本文选题：再生保温混凝土　切入点：力学性能　出处：《太原理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：再生保温混凝土(RATIC)是一种多功能绿色混凝土,因在配制过程中利用了建筑垃圾-废旧混凝土和玻化微珠保温颗粒,从而它具有保温、环保、轻质承重等优势。再生骨料的合理利用不仅缓解了我国天然砂石资源匮乏的压力,而且缓解了由于大量建筑垃圾堆积产生的环境压力;保温骨料的加入则使得混凝土导热系数降低,实现了混凝土建筑保温系统和结构系统同服役周期。再生保温混凝土具有广阔的应用前景。尺寸效应是准脆性材料的重要特征,其强度会随着尺寸的增加而降低。混凝土作为一种脆性材料,也具有这种特征,本文以课题组已有研究为基础,开展再生保温混凝土力学性能尺寸效应研究,揭示其在不同再生骨料取代率和不同强度等级下力学性能的尺寸效应,并与普通混凝土、再生混凝土和保温混凝土进行对比分析,为工程应用提供基础数据。本文主要内容包括:(1)不同再生骨料取代率下再生保温混凝土尺寸效应研究。以C40强度等级RATIC为基准,设计0%、30%、50%、70%、100%五种再生骨料取代率,采用不同尺寸试块,开展力学性能尺寸效应试验。结果表明:试块尺寸一致时,随着取代率的提高,混凝土强度提高,弹性模量在50%达到最大值;随着取代率的增加,边长200mm的RATIC尺寸效应度分别为12.4%、20.5%、20.5%、7.4%和15.6%,这与混凝土强度随再生骨料替代率变化的规律一致。(2)不同强度等级的再生保温混凝土尺寸效应研究。采用C30、C40、C50三种强度等级RATIC,取再生骨料取代率为50%,开展力学性能尺寸效应试验。结果表明:随着强度等级的提高,尺寸效应增强,拉压比减小,混凝土脆性增强。C30、C40、C50强度等级的RATIC抗压强度尺寸效应度分别为10.4%、20.5%和19.8%。(3)不同类型混凝土尺寸效应研究。设计同强度等级的普通混凝土、再生混凝土和保温混凝土,对比分析再生骨料、保温骨料及其共同作用对混凝土尺寸效应的影响。结果表明:四种混凝土的强度均随着试块尺寸的增大而降低,但尺寸效应显著程度不同,设计强度为C40的普通混凝土、再生混凝土、保温混凝土以及再生保温混凝土的尺寸效应度分别为6.7%、9.2%、12.4%、7.4%-11.9%。四种混凝土的弹性模量并没有表现出明显的尺寸效应,其值变化在3%范围内。
[Abstract]:The recycled insulating concrete (RATIC) is a kind of multifunctional green concrete. It has the advantages of heat preservation and environmental protection because of the use of construction garbage-waste concrete and vitrified microbead insulation particles in the preparation process. The reasonable utilization of recycled aggregate not only alleviates the pressure of the shortage of natural sand and stone resources in our country, but also relieves the environmental pressure caused by the accumulation of a large amount of construction waste. The thermal conductivity of concrete is reduced with the addition of thermal insulation aggregate, and the thermal insulation system and structure system of concrete buildings have the same service cycle. The regenerated thermal insulation concrete has a broad application prospect. Size effect is an important feature of quasi-brittle materials. The strength of concrete decreases with the increase of size. As a brittle material, concrete also has this characteristic. In this paper, the size effect of mechanical properties of recycled insulating concrete is studied on the basis of the previous research by our research group. The size effect of mechanical properties under different recycled aggregate substitution rates and different strength grades is revealed, and compared with ordinary concrete, recycled concrete and insulating concrete. To provide basic data for engineering application. The main contents of this paper include: 1) study on the size effect of recycled insulating concrete under different recycled aggregate replacement rates. Based on C40 strength grade RATIC, the paper designs the replacement rate of 50% recycled aggregate and 100% recycled aggregate. The size effect test of mechanical properties was carried out with different sizes of specimens. The results showed that the strength of concrete increased with the increase of substitution ratio, and the elastic modulus reached the maximum value at 50%, and with the increase of substitution rate, the strength of concrete increased with the increase of replacement ratio. The dimension effect degree of RATIC with side length of 200mm is 12.4% and 15.6mm, respectively, which is consistent with the rule of concrete strength changing with recycled aggregate substitution rate. The size effect of recycled recycled concrete with different strength grades is studied by using C30C40C50 three strength grades RATIC. The size effect test of mechanical properties was carried out with the replacement rate of regenerated aggregate as 50. The results showed that: with the increase of strength grade, The size effect of RATIC compressive strength of concrete brittleness. C30 and C40C50 are 10.4% and 19.8% respectively. Design of ordinary concrete of the same strength grade, the size effect of concrete of different types is increased, the ratio of tension to compression is reduced, and the size effect of RATIC compressive strength is 10.4% and 19.8% respectively. The effects of recycled aggregate, thermal insulation aggregate and their interaction on the size effect of recycled concrete and thermal insulation concrete are compared and analyzed. The results show that the strength of the four kinds of concrete decreases with the increase of the size of the specimen. But the size effect is different. Ordinary concrete with a design strength of C40, recycled concrete, The dimensional effects of insulating concrete and recycled insulating concrete are 6.79.2and 12.4and 7.4- 11.9respectively. The elastic modulus of the four kinds of concrete does not show obvious size effect, and its value varies in the range of 3%.
【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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