煅烧煤矸石粉的制备及其对混凝土性能影响研究

发布时间：2018-05-14 03:21

本文选题：矿物掺合料 + 煤矸石　；参考：《辽宁工程技术大学》2015年硕士论文

【摘要】：矿物掺合料是指在配制混凝土时加入的改善新拌混凝土和硬化混凝土能性的无机矿物细粉。作为一种辅助胶凝材料,它己成为高性能混凝土不可缺少的第六组分。煅烧煤矸石作为矿物掺合料,一能减少水泥用量,降低能耗；二能将煤矸石变废为宝,并减轻环境污染；三能改善混凝土的各项性能,提高工程质量,是实现煤矸石资源化利用的一条重要途径。本文是国家自然科学基金煤炭联合项目《煤矸石在水泥和混凝土资源化利用中关键科学问题研究》(U1261122)的子项目,所有研究成果都是在该基金的资助下完成并取得的。本文首先采用热活化和机械活化复合的方式,激发煤矸石潜在的活性。接下来通过煤矸石-水泥胶砂的流动度和强度试验,确定煤矸石的最佳煅烧温度和最佳粉磨时间；在此基础上,选择掺合料复掺品种、掺量两个影响因素,进行正交试验研究,通过混凝土稠度和强度试验,研究二者对混凝土拌合物工作性,以及7d、28d、60d和90d抗压强度的影响,给出最佳配合比。最后对最优配合比成型的试件进行混凝土抗压及劈拉强度、抗氯离子渗透和抗冻融循环的试验研究。研究结果表明：(1)阜新清河门矿未燃煤矸石,经过机械和热处理,满足作为混凝土掺合料的基本要求,作混凝土掺合料是可行的。(2)煅烧煤矸石粉作为混凝土矿物掺合料可显著改善新拌混凝土的工作性能,降低混凝土拌合物的经时损失,改善混凝土的可泵性。在改善混凝土工作性方面,煅烧煤矸石粉具有比相同细度的矿粉更优良的性能,但稍逊于粉煤灰。(3)煅烧煤矸石粉的活性介于粉煤灰和矿粉之间,作为掺合料用于混凝土中,可以起到火山灰效应,对混凝土后期强度的增进率贡献较大。(4)当煅烧煤矸石粉分别与粉煤灰、矿粉复掺时,随着煅烧煤矸石粉掺量的增加,混凝土强度表现为先增加后减小,煅烧煤矸石粉与矿粉或粉煤灰复掺比例为3：7时,混凝土28d抗压强度都达到了峰值。(5)煅烧煤矸石粉与粉煤灰或矿粉复掺使用时,混凝土抗氯离子渗透等级达到了中级水平；煅烧煤矸石粉与粉煤灰复合使用,能使混凝土的抗冻融循环次数达到550次。与矿粉复合使用,混凝土抗冻融循环次数达到500次。煅烧煤矸石粉与粉煤灰的相容性最好。
[Abstract]:Mineral admixture is the inorganic mineral powder that is used to improve the energy of fresh concrete and hardened concrete. As an auxiliary cementitious material, it has become an indispensable sixth component of high performance concrete. As a mineral admixture, calcined coal gangue can, first, reduce cement consumption and reduce energy consumption; second, it can turn coal gangue into a treasure and reduce environmental pollution; third, it can improve the properties of concrete and improve the engineering quality. It is an important way to realize the utilization of coal gangue. This paper is a sub-project of the National Natural Science Foundation coal joint project < Research on key Scientific problems of Coal gangue in cement and concrete Recycling Utilization "U1261122). All the research results have been completed and obtained with the aid of the fund. In this paper, the potential activity of coal gangue is stimulated by the combination of thermal activation and mechanical activation. Then through the fluidity and strength test of coal gangue cement sand, the optimum calcination temperature and grinding time of coal gangue are determined. The effects of consistency and strength of concrete on the workability of concrete mixture and the compressive strength of concrete for 60 d and 90 d were studied and the optimum mix ratio was given. Finally, the compressive strength, splitting tensile strength, chloride ion penetration resistance and freezing and thawing cycle resistance of concrete were studied. The results show that the unburned coal gangue in Fuxin Qinghemen Mine meets the basic requirements of concrete admixture after mechanical and heat treatment. It is feasible to use coal gangue powder as mineral admixture to improve the performance of fresh concrete, reduce the time loss of concrete mixture, and improve the pumpability of concrete. In improving the workability of concrete, calcined coal gangue powder has better performance than ore powder of the same fineness, but the activity of calcined coal gangue powder is between fly ash and ore powder, which is used as admixture in concrete. When calcined coal gangue powder is mixed with fly ash and mineral powder respectively, with the increase of the content of calcined coal gangue powder, the strength of concrete increases first and then decreases. When the ratio of calcined coal gangue powder to mineral powder or fly ash is 3:7, the compressive strength of concrete reaches the peak value in 28 days.) when the calcined coal gangue powder is mixed with fly ash or mineral powder, the grade of chloride ion permeation of concrete reaches the intermediate level. The composite use of calcined coal gangue powder and fly ash can make the times of freeze-thaw resistance of concrete up to 550 times. When combined with mineral powder, the times of freezing and thawing resistance of concrete reach 500 times. The compatibility of calcined coal gangue powder and fly ash is the best.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU528

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