高硅型铁尾矿对混凝土和易性及抗压强度影响试验研究

发布时间：2018-01-14 22:03

本文关键词：高硅型铁尾矿对混凝土和易性及抗压强度影响试验研究　出处：《东北大学》2013年硕士论文　论文类型：学位论文

【摘要】：本文选择高硅型铁尾矿作为研究对象(尾矿来源于辽宁省鞍山齐大山铁矿)。对该种尾矿进行了性能测试及分析,包括尾矿的化学成分分析、矿物成分分析、粒度分析、活性分析,分析结果表明,该尾矿的主要化学成分为SiO2,主要矿物成分为石英,粒度集中分布在120μm,无火山灰活性。基于机械力化学基本原理,将所研究的尾矿进行机械力粉磨,经过粉磨,其粒度达到了12.231μm。XRD显示,粉磨后的SiO2结晶程度降低明显,火山灰性合格。经过机械力化学活化的高硅型铁尾矿与水泥复合而成的复合胶凝材料,标准稠度用水量、初终凝时间与水泥的标准稠度用水量、初终凝时间相近,安定性合格。将经机械力化学活化的高硅型铁尾矿作为混凝土辅助胶凝材料,以一定的比例取代水泥配制混凝土,通过试验探索该尾矿对混凝土拌合物和易性及抗压强度的影响。和易性试验结果表明：随着尾矿掺量的增加,混凝土拌合物的坍落度降低,混凝土拌合物的粘聚性和保水性随着尾矿掺量的增加增强。尾矿取代水泥的量为20%时,混凝土拌合物坍落度满足设计要求。抗压强度试验结果表明：随着尾矿取代水泥量的增加,混凝土强度有不同程度的下降,尾矿取代水泥量不超过30%,满足设计强度C30要求。掺入减水剂可显著提高混凝土抗压强度,此时,尾矿取代水泥量为40%时仍能达到设计强度C30。通过XRD及SEM对水泥硬化浆体及尾矿一水泥硬化浆体进行了物相及微观测试分析,试验结果表明,同龄期比较Ca(OH)2最强衍射峰总是出现在水泥净浆一组；同时,SEM显示随着龄期的增加,未反应的尾矿颗粒表面逐渐被水化产物覆盖,和同龄期水泥净浆比较,尾矿-水泥硬化浆体一组水化产物以C-S-H为主,相对水泥净浆组较少观察到Ga(OH)2。根据胶凝材料基本理论及机械力化学活化尾矿性能,判断尾矿-水泥浆体中发生了二次水化反应,
[Abstract]:In this paper, high silicon type iron tailings are selected as the research object (tailings originated from Qidashan Iron Mine, Anshan, Liaoning Province). The properties of the tailings are tested and analyzed, including the analysis of the chemical composition and mineral composition of the tailings. The results of particle size analysis and activity analysis show that the main chemical composition of the tailings is SiO2, the main mineral component is quartz, and the particle size is concentrated at 120 渭 m. No pozzolanic activity. Based on the basic principle of mechanochemistry, the tailings were milled by mechanical force. The particle size of the tailings was 12.231 渭 m 路XRD. The crystallization degree of SiO2 after grinding is obviously decreased and the pozzolanic property is qualified. The standard consistency water consumption is obtained by the composite cementing material composed of high silicon iron tailings and cement after mechanochemical activation. The initial and final setting time is similar to the standard consistency water consumption of cement, the initial and final setting time is close and the stability is qualified. The high silicon iron tailings activated by mechanochemistry are used as the concrete auxiliary cementing materials. The effect of the tailings on the mixing property and compressive strength of the concrete was studied by experiments, and the results showed that the content of tailings increased with the increase of the content of tailings. The slump of concrete mixture decreases, and the cohesion and water retention of concrete mixture increase with the increase of tailings content. The quantity of cement replaced by tailings is 20. The results of compressive strength test show that the strength of concrete decreases in varying degrees with the increase of the amount of cement replaced by tailings, and the amount of cement replaced by tailings is less than 30%. The compressive strength of concrete can be significantly improved by adding water reducer to meet the requirement of design strength C30. The design strength C30 can still be achieved when the content of cement replaced by tailings is 40. The phase and microcosmic analysis of cement hardened paste and tailings cement hardened paste are carried out by XRD and SEM, and the results show that. The strongest diffraction peaks of Ca(OH)2 in the same age period always appear in the cement paste group. At the same time, SEM showed that the surface of unreacted tailings was gradually covered by hydration products with the increase of age, which was compared with the cement paste of the same age. C-S-H is the main hydration product of tailings and cement hardened paste. Compared with the pure cement slurry group, there is less GaOH ~ (2). According to the basic theory of cementitious material and mechanochemical activation of tailings, the results are as follows: (1) the main hydration product of tailings is C-S-H. Judging that the secondary hydration reaction occurred in the tailings and cement paste,
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU528

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