高硅型铁尾矿对混凝土抗渗性及抗硫酸盐腐蚀性影响试验研究

发布时间：2018-12-28 08:37

【摘要】：本文采用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。该尾矿的主要化学成份为SiO2,主要矿物成份为石英,粒度集中分布在120微米左右。依据机械力化学基本原理,将所研究的尾矿进行机械力粉磨,其颗粒D50约达到了9.4微米。XRD微观试验分析,粉磨后的SiO2结晶程度降低明显,火山灰性合格。高硅型铁尾矿经过机械力化学活化后作为混凝土辅助胶凝材料,以10%、20%、30%、40%比例取代水泥配制混凝土,通过试验探索该尾矿对混凝土抗渗性和抗硫酸盐腐蚀性的影响。抗渗性共设计10组配合比试件,其中抗渗性试验试件包括掺减水剂和不掺减水剂混凝土两大系列,每一系列5组,包括无掺合料(基准混凝土)1组,尾矿部分取代水泥混凝土4组；抗硫酸盐腐蚀试件20组,其中清水中浸泡10组,硫酸盐溶液中浸泡10组。研究结果表明：高硅型铁尾矿部分取代水泥混凝土的抗渗性能优于基准混凝土的抗渗性,不掺减水剂尾矿取代水泥量可达30%,掺减水剂取代水泥量提高到40%；尾矿部分取代水泥混凝土抗硫酸盐腐蚀性能优于基准混凝土抗硫酸盐腐蚀性能,尾矿取代水泥量可达40%。针对水泥硬化浆体及尾矿-水泥硬化浆体进行XRD分析,分析结果表明,同龄期硬化浆体比较,尾矿-水泥浆体一组Ca(OH)2最强衍射峰总是低于水泥净浆一组。基于机械力化学活化尾矿性能及胶凝材料学基本理论,可以判断在尾矿-水泥浆体中发生了二次水化反应。
[Abstract]:In this paper, high silicon iron tailings are used as the research object. The tailings come from Qidashan Iron Mine in Anshan, Liaoning Province. The main chemical composition of the tailings is quartz, the main mineral component of SiO2, is quartz, and the particle size distribution is about 120 渭 m. According to the basic principle of mechanochemistry, the particle D50 of the tailings is about 9.4 渭 m by mechanical grinding. The results of XRD microcosmic test show that the degree of crystallization of SiO2 after grinding is obviously reduced and the pozzolanic property is up to standard. High silicon iron tailings are used as concrete auxiliary cementing materials after mechanically and chemically activated, and the cement is replaced by 10% or 20% cement to make concrete. The effects of the tailings on the impermeability and sulfate corrosion resistance of concrete were investigated. Impermeability is designed for 10 groups of mix specimens, in which impermeability test specimens include two series of concrete with and without water reducer, 5 groups per series, including 1 group without admixture (benchmark concrete), Tailings partially replaced 4 groups of cement concrete; There were 20 groups of sulfate corrosion resistant specimens, of which 10 groups were soaked in clear water and 10 groups in sulfate solution. The results show that the impermeability of cement concrete partially replaced by iron tailings of high silicon type is better than that of standard concrete. The quantity of cement replaced by tailings without superplasticizer can reach 30%, and the quantity of cement replaced by water reducing agent can be increased to 40%. The corrosion resistance of cement concrete partially replaced by tailings is better than that of benchmark concrete, and the quantity of cement replaced by tailings is up to 40. XRD analysis was carried out for cement hardened paste and tailings cement hardened slurry. The results showed that the strongest diffraction peak of Ca (OH) 2 in tailings cement paste group was always lower than that in cement paste group. Based on the basic theory of mechanochemically activated tailings and cementitious materials, the secondary hydration reaction in tailings and cement paste can be judged.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU528

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