白云石粉混凝土复合矿物掺合料的研究

发布时间：2018-03-31 02:01

本文选题：白云石　切入点：混凝土复合矿物掺合料　出处：《吉林建筑大学》2014年硕士论文

【摘要】：本论文通过试验研究了将细磨白云石粉加入水泥胶砂及混凝土中,利用水泥里的碱与白云石发生的碱-碳酸盐反应能产生体积膨胀的原理,制备出具有抗渗、抗冻功能的混凝土复合矿物掺合料。这一技术会对功能性混凝土复合矿物掺合料的生产和推广应用将会起到良好的促进作用。混凝土在凝结硬化过程中,由于混凝土中水分的变化、水泥的水化反应、温度变化等原因,均会导致混凝土产生一定的体积收缩。混凝土体积收缩以及由体积收缩引起的裂缝对混凝土自身的承载能力、工作性能、耐久性能等均会产生不利的影响。本论文通过对养护龄期内试件抗压强度及膨胀收缩变化的测定,证实了在水泥中掺入一定数量的白云石粉可对水泥体积收缩产生一定的补偿作用。用X射线衍射证明了在水泥中掺入的白云石粉经过水化已经形成了新的水化产物。用扫描电镜观察对比试件的微观结构,证实了在水泥中掺入白云石粉发生了碱-碳酸盐膨胀反应,消除了水泥水化体积收缩形成的显微裂缝。由水泥胶砂试件的抗压强度试验,了解了白云石粉含量对水泥强度的影响,证实了白云石粉的掺入对水泥的抗压强度和抗折强度均无明显的不良影响。本论文还进一步分析了不同碱作为引发剂及其掺量对水泥胶砂试件强度的影响,从而得出白云石的活性及其适合的碱引发剂,最后本文还对白云石粉掺量不同的混凝土试件进行了强度、抗冻、抗碳化、抗渗等性能的试验,经过分析讨论得出白云石复合矿物掺合料能很好的提高混凝土的抗渗、抗碳化性能。所以利用碱激发白云石能产生体积膨胀的原理,制备出具有抗渗、抗碳化性能的混凝土复合掺合料,理论可靠、材料用量少、效果明显、造价低廉,在混凝土以及砂浆的生产和使用方面,将具有广阔的市场前景和较高的推广价值。
[Abstract]:In this paper, the principle of volume expansion was studied by adding fine grinding dolomite powder into cement sand and concrete, and the impermeability was obtained by using alkali and dolomite reaction in cement to produce volume expansion. This technology will play a good role in the production and application of functional concrete compound mineral admixture. Because of the change of water content in concrete, the hydration reaction of cement, the change of temperature and so on, the concrete will produce certain volume shrinkage, and the concrete volume shrinkage and the crack caused by volume shrinkage will bring about the bearing capacity of concrete itself. In this paper, the compressive strength and expansion shrinkage of the specimens during the curing period were measured. It is proved that adding a certain amount of dolomite powder into cement can compensate the volume shrinkage of cement. X-ray diffraction shows that the dolomite powder mixed in cement has formed a new hydration yield after hydration. The microstructure of the specimen was observed and compared by scanning electron microscope (SEM). It has been proved that the alkali carbonate expansion reaction occurred in the cement mixed with dolomite powder, which eliminated the microcracks formed by the shrinkage of cement hydration volume. The influence of dolomite content on cement strength was studied. It was proved that the addition of dolomite powder had no obvious adverse effect on the compressive strength and flexural strength of cement. The effect of different alkali as initiator and its content on the strength of cement mortar was further analyzed in this paper. The activity of dolomite and its suitable alkali initiator are obtained. Finally, the strength, freezing resistance, carbonization resistance, impermeability and other properties of concrete specimens with different dolomite content are tested. Through analysis and discussion, it is concluded that dolomite compound mineral admixture can improve the impermeability and carbonation resistance of concrete very well. Therefore, by using the principle of volume expansion of dolomite excited by alkali, the impermeability is prepared. The carbonation resistant concrete compound admixture has the advantages of reliable theory, less material consumption, obvious effect and low cost. It will have a broad market prospect and high popularizing value in the production and use of concrete and mortar.
【学位授予单位】：吉林建筑大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU528

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