Development of novel mineral admixtures for sulphoaluminate cement clinker: The effects of wet carbonation activated red mud. (15th May 2023)

• Record Type: Journal Article
• Authors: Liu, Songhui; Pan, Chao; Zhang, Haibo; Yao, Suwan; Shen, Peiliang; Guan, Xuemao; Shi, Caijun; Li, Haiyan
• Is Part Of: Journal of building engineering. Volume 67(2023)
• Publication Date: 2023-05-15
• Subjects: Sulphoaluminate cement clinker -- Sintering red mud -- In-situ wet carbonation -- Compressive strength -- Hydration products; Building -- Periodicals; 690.05
• DOI: 10.1016/j.jobe.2023.105920
• Languages: English
• ISSNs: 2352-7102

Abstract

Abstract: In our previous work, an in situ wet carbonation method was proposed to enhance the activity of waste-sintering red mud (SRM) by producing large amounts of fine calcium carbonate and silica-aluminum gels. This paper further investigates the effect of carbonated SRM (C-SRM) dosing (0%, 5%, 10%, 15%, 20% and 25%) on the hydration-hardening properties of sulphoaluminate cement (CSA) clinker paste, such as flowability, setting time, reaction temperature, compressive strength, microstructure and pore structure evolution. The results show that the use of C-SRM as a new mineral admixture not only significantly improves early strength but also effectively compensates for the strength deficit of CSA clinker due to the conversion of AFt to AFm at a later stage. When the C-SRM content is 20%, the compressive strength reached its maximum at all ages, with the 1 d compressive strength increasing by 96.9% and the 90 d compressive strength by 19.8%. The microstructure analysis shows that the C-SRM has a good crystalline nucleation effect and can participate in the hydration reaction of CSA clinker, forming semi-carbonate aluminates and stabilizing ettringite, thus densifying the microstructure of the hardened paste. The above results open new possibilities for incorporating C-SRM as a novel mineral admixture into CSA clinker while further reducing CO2 emissions. Highlights: The maximum compressive strength was reached when the dose of C-SRM was 20%. The incorporation of C-SRM can form semi-carbonate aluminates and stabilizing the ettringite. The incorporation of C-SRM not only save costs but also allow effective sequestration of CO2 .