Pengfei Wu , Chao Wei , Xiaoming Liu , Zengqi Zhang , Yang Xue , Xinyue Liu
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引用次数: 0
Abstract
Red mud (RM), a waste by-product of alumina production, is increasingly used in cementitious materials. However, the high iron content and alkaline substances in RM, in addition to heavy metal elements, hinder its utilisation in cementitious materials. To overcome these issues, a ternary system of RM, blast furnace slag (BFS), and cement was prepared to assess the effects of iron in RM on hydration and environmental performance. The results indicated that 97 % of the iron in RM exists in the form of Hematite. As the Hematite content in the system increases, the cumulative hydration heat, heavy metal immobilisation rate, hydration-product content, degree of polymerisation, initial and final setting times, as well as early compressive strength gradually decrease. However, the later strength of the matrix initially increases and then decreases. In addition, the soluble alkali in RM was utilised. When the Hematite content in the system is between 2.47 % and 7.82 % (corresponding to 9.68 %–31.28 % Hematite in RM), the mechanical properties of the matrix meet PO.42.5 standards, and the concentrations of hazardous elements such as Na in the leachate comply with China's drinking water standards (GB/T 5749-2022).
期刊介绍:
Cement & concrete composites focuses on advancements in cement-concrete composite technology and the production, use, and performance of cement-based construction materials. It covers a wide range of materials, including fiber-reinforced composites, polymer composites, ferrocement, and those incorporating special aggregates or waste materials. Major themes include microstructure, material properties, testing, durability, mechanics, modeling, design, fabrication, and practical applications. The journal welcomes papers on structural behavior, field studies, repair and maintenance, serviceability, and sustainability. It aims to enhance understanding, provide a platform for unconventional materials, promote low-cost energy-saving materials, and bridge the gap between materials science, engineering, and construction. Special issues on emerging topics are also published to encourage collaboration between materials scientists, engineers, designers, and fabricators.