纳米混凝土的制备及其干缩性能研究

发布时间：2018-05-24 01:01

本文选题：纳米混凝土 + 内部结构　；参考：《东北大学学报(自然科学版)》2017年08期

【摘要】：采用试验研究与理论分析相结合的方法,在普通混凝土中分别掺入不同量的纳米二氧化硅(Nano-SiO_2)和纳米碳酸钙(Nano-CaCO_3),制备出新型纳米混凝土.通过微观电镜试验分析了不同纳米材料对混凝土内部结构变化的影响规律.通过干缩性能试验对比研究了不同纳米材料对混凝土干缩率的影响及作用机理,并确定出最佳掺入量.研究结果表明:Nano-SiO_2和Nano-CaCO_3均能改变混凝土的干缩率,但对干缩率改变的效果不尽相同;掺入Nano-SiO_2的混凝土试件,其干缩率随掺量的变化比掺入Nano-CaCO_3试件的干缩率变化更为明显,当Nano-SiO_2的掺量为0.5%或Nano-CaCO_3的掺量为2.0%时,混凝土试件的干缩率最小.研究还发现,混凝土的干缩与混凝土自身密实程度、弯月面产生的数量以及内部湿度存在着动态平衡的关系.
[Abstract]:By combining the experimental study with theoretical analysis, a new type of nano-concrete was prepared by adding Nano-SiO-2 (nano-silica) and Nano-CaCO _ 3 (Nano-CaCO _ 3) respectively into ordinary concrete. The influence of different nano-materials on the internal structure of concrete was analyzed by microscopic electron microscope test. The effect and mechanism of different nano-materials on shrinkage rate of concrete were studied by dry shrinkage test, and the optimum blending amount was determined. The results show that both: Nano-SiO _ 2 and Nano-CaCO_3 can change the dry shrinkage rate of concrete, but the effect of the change of dry shrinkage rate is not the same, and the dry shrinkage rate of concrete specimens doped with Nano-SiO_2 is more obvious than that of Nano-CaCO_3 specimen. When the content of Nano-SiO_2 is 0.5% or the content of Nano-CaCO_3 is 2.0, the shrinkage rate of concrete specimen is minimum. It is also found that there is a dynamic equilibrium relationship between the shrinkage of concrete and the density of concrete itself, the amount of meniscus produced and the internal humidity.
【作者单位】：东北大学资源与土木工程学院;沈阳大学建筑工程学院;
【基金】：国家科技支撑计划项目(2013BAJ15B03)
【分类号】：TU528

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