泥质页岩煤矸石对混凝土常温及高温性能影响

发布时间：2018-07-10 16:21

  本文选题：泥质页岩煤矸石 + 混凝土　； 参考：《哈尔滨工业大学》2015年硕士论文

【摘要】：煤矸石是在煤炭开采和洗选加工过程中产出的固体废弃物,是碳质、砂质和泥质页岩的混合物,其巨大的排放量和露天堆存现象造成严重的土壤、水体和大气污染,破坏生态环境和景观,给人类的生存和经济的发展造成危害。研究表明,煤矸石被广泛使用在填充材料、替代混凝土骨料或者水泥掺合料等方面,其中将煤矸石用作混凝土骨料具有投资少、易开采、使用量大、加工简单及综合利用效果明显等优点得到普遍应用。近年来,随着建筑行业的蓬勃发展以及建筑安全事故的频繁发生,建筑的安全性也越来越受到重视,在利用煤矸石配制混凝土方面,常温下的性能研究已经比较成熟,但在高温下依靠自身的材料强度或者煤矸石活性的激发来维持煤矸石混凝土的正常使用方面研究比较少,且没有比较完整的试验数据支持。本研究目的是通过对泥质页岩煤矸石对混凝土常温及高温下强度和体积稳定性等性能影响的研究,探索煤矸石混凝土在常温下能够保持结构的安全度并在高温下能够正常使用的应用条件。以煤矸石混凝土的强度、体积稳定性及耐久性等宏观性能为基础,确定煤矸石作为粗骨料的最优取代率,研究表明:随着煤矸石掺量的增加,煤矸石混凝土的抗压强度及干缩逐渐增大,抗渗、抗冻性逐渐降低,静弹性模量先增大后减小,当取代率为20%时最大。结合微观结构分析手段探索泥质页岩煤矸石对混凝土处于不同温度条件下(常温、200℃、300℃、400℃、500℃、600℃、700℃、800℃、900℃)的性能影响机理,结果表明:随着泥质页岩煤矸石掺量的增加以及经历温度的升高,煤矸石混凝土的抗压强度逐渐减小,破坏情况越来越严重。煤矸石的活性在高温下并没有得到激发,无法提高混凝土的抗高温性能,因此在对煤矸石混凝土进行生产制备过程中要注意对泥质页岩煤矸石掺量的控制,以保证建筑材料及结构构件的安全度。
[Abstract]:Coal gangue is a solid waste produced in the process of coal mining and washing and processing. It is a mixture of carbonaceous, sandy and muddy shale. Its huge discharge and open-air storage cause serious soil, water and air pollution. Damage to the ecological environment and landscape, human survival and economic development caused harm. The research shows that coal gangue is widely used in filling material, replacing concrete aggregate or cement admixture and so on, in which coal gangue is used as concrete aggregate with less investment, easy to be mined and large amount of usage. The advantages of simple processing and obvious comprehensive utilization are widely used. In recent years, with the vigorous development of the construction industry and the frequent occurrence of building safety accidents, the building safety has been paid more and more attention. In the use of coal gangue to prepare concrete, the performance research at room temperature has been relatively mature. However, the research on maintaining the normal use of coal gangue concrete under high temperature depends on its own material strength or the activation of coal gangue activity, and there is no complete test data to support it. The purpose of this study is to study the effect of shale coal gangue on strength and volume stability of concrete at room temperature and high temperature. To explore the application conditions of coal gangue concrete which can keep the safety of structure at room temperature and can be used normally at high temperature. Based on the macroscopic properties of coal gangue concrete, such as strength, volume stability and durability, the optimum substitution rate of coal gangue as coarse aggregate is determined. The compressive strength and dry shrinkage of coal gangue concrete increase gradually, the impermeability and frost resistance decrease gradually, and the static elastic modulus increases first and then decreases, and the maximum is when the replacement ratio is 20. The influence mechanism of shale coal gangue on the properties of concrete at different temperatures (200 鈩，

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