Xu Dong, Fu Pingfeng, Ni Wen, Wang Qunhui, Li Keqing
School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Beijing Key Laboratory on Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, China.
Materials (Basel). 2021 Aug 24;14(17):4794. doi: 10.3390/ma14174794.
The use of ammonia soda residue (ASR) to prepare building materials is an effective way to dispose of ASR on a large scale, but this process suffers from a lack of data and theoretical basis. In this paper, a composite cementitious material was prepared using ASR and cement, and the hydration mechanism of cementitious materials with 5%, 10%, and 20% ASR was studied. The XRD and SEM results showed that the main hydration products of ASR-cement composite cementitious materials were an amorphous C-S-H gel, hexagonal plate-like Ca(OH) (CH), and regular hexagonal plate-like Friedel's salt (FS). The addition of ASR increased the heat of hydration of the cementitious material, which increased upon increasing the ASR content. The addition of ASR also reduced the cumulative pore volume of the hardened paste, which displayed the optimal pore structure when the ASR content was 5%. In addition, ASR shortened the setting time compared with the cement group, and the final setting times of the pastes with 5%, 10%, and 20% ASR were 30 min, 45 min, and 70 min shorter, respectively. When the ASR content did not exceed 10%, the 3-day compressive strength of the mortar was significantly improved, but the 28-day compressive strength was worse. Finally, the hydration mechanism and potential applications of the cementitious material are discussed. The results of this paper promote the use of ASR in building materials to reduce CO emissions in the cement industry.
利用氨碱废渣（ASR）制备建筑材料是大规模处理ASR的有效途径，但该过程缺乏数据和理论依据。本文采用ASR和水泥制备了一种复合胶凝材料，并研究了ASR含量分别为5%、10%和20%的胶凝材料的水化机理。XRD和SEM结果表明，ASR-水泥复合胶凝材料的主要水化产物为无定形C-S-H凝胶、六方板状Ca(OH)₂（CH）和规则六方板状Friedel盐（FS）。ASR的加入提高了胶凝材料的水化热，且随着ASR含量的增加而增大。ASR的加入还降低了硬化浆体的累积孔隙体积，当ASR含量为5%时孔隙结构最佳。此外，与水泥组相比，ASR缩短了凝结时间，ASR含量为5%、10%和20%的浆体的终凝时间分别缩短了30分钟、45分钟和70分钟。当ASR含量不超过10%时，砂浆的3天抗压强度显著提高，但28天抗压强度较差。最后，对该胶凝材料的水化机理和潜在应用进行了讨论。本文结果促进了ASR在建筑材料中的应用，以减少水泥行业的CO₂排放。
