Influence of red mud on fresh and hardened properties of self-compacting concrete
Influence of red mud on fresh and hardened properties of self-compacting concrete
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DOI：
10.1016/j.conbuildmat.2018.05.171
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发表时间：
2018-07-30
影响因子：
7.4
通讯作者：
Cui, H. Z.
中科院分区：
文献类型：
--
作者：
Tang, W. C.;Wang, Z.;Cui, H. Z.
赤泥是氧化铝生产过程中产生的一种废弃物，目前其工业用途有限。本研究提出用赤泥部分取代粉煤灰（12.5%、25%和50%）配制自密实混凝土（SCC），并研究了赤泥对SCC新拌和硬化性能及微观结构的影响。对新鲜SCC混合物进行了坍落流、T-500和J形环试验。研究了赤泥自密实混凝土的抗压强度、抗拉强度和弹性模量等硬化性能。采用X射线衍射仪（XRD）、扫描电镜（SEM）和能谱仪（EDS）对赤泥混凝土样品的化学成分和微观结构进行了分析。结果表明，混凝土的力学强度随赤泥掺量的增加而提高。由50%的赤泥组成的SCC样品的抗压强度和弹性模量表现最好。微观研究结果表明，与对照混凝土相比，赤泥混凝土骨料与水泥浆体之间的界面过渡区（ITZ）略有改善。XRD结果表明，掺赤泥水泥浆体的化学组成中钠和铁的含量较高。随着赤泥掺量的增加，XRD也发现了一些呈三斜晶系的钠长石晶体。(C)2018爱思唯尔有限公司版权所有。
Red mud is a waste product from the production of alumina, it currently has limited industrial use. This study proposed to use red mud to partially replace fly ash (12.5, 25 and 50% by weight) in self-compacting concrete (SCC) and the influence of red mud on the fresh and hardened properties and microstructural behaviour of SCC were studied. Slump-flow, T-500 and J-ring tests were carried out on fresh SCC mixtures. The hardened properties of red mud SCCs including compressive strength, tensile strength and elastic modulus were studied. Moreover, the chemical composition and microstructural properties of red mud concrete samples were analysed using X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS), respectively. The results show that the mechanical strength of concrete increased with increasing red mud content. SCC samples consisting 50% red mud performed the best for the compressive strength and elastic modulus. The results from microscopic studies indicated that there was a slight improvement in the interfacial transition zone (ITZ) between aggregate and cement paste for red mud concrete compared with control concrete. The XRD results indicated that the chemical composition of cement paste containing red mud showed higher sodium and iron contents. With increasing red mud content, some albite crystals appearing in triclinic shape were also identified by XRD. (C) 2018 Elsevier Ltd. All rights reserved.