Wang Jintang, Deng Xiufeng, Tan Hongbo, Guo Huiyong, Zhang Junjie, Li Maogao, Chen Pian, He Xingyang, Yang Jin, Jian Shouwei, Yang Zhuowen
State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, PR China.
State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, PR China; National Engineering Laboratory for Fiber Optic Sensing Technologies, Wuhan University of Technology, Wuhan 430070, PR China.
Sci Total Environ. 2023 Dec 10;903:166015. doi: 10.1016/j.scitotenv.2023.166015. Epub 2023 Aug 12.
The cementitious material based on phosphogypsum (PG) and ground granulated blast furnace slag (GBFS) demonstrates good economy and sustainability, whereas its drawback of ultra-slow strength development seems unacceptable. In this study, an attempt to drive the hydration of PG-GBFS and further facilitate the strength development by introducing nano-ettringite (NE) was carried out. The impact of 1- 5 % NE on the compressive strength, hydration process, dissolution behavior, and microstructure evolution of PG-GBFS were investigated. The results showed that the incorporation of NE significantly increased the compressive strength of PG-GBFS. At 7 d, the strength grew from 0 MPa to a range of 7.6- 20.2 MPa, and at 28 d, it was enhanced from 22.9 MPa to a range of 45.6- 79.0 MPa. The reason was that the introduction of NE induced the formation of AFt, thereby accelerating the hydration process and promoting the development of the skeletal network, resulting in higher early strength. Besides, NE facilitated the formation of C-S(A)-H gel, which further refined the pore structure and led to continuous growth in later strength. Additionally, PG-GFBS with 5 % NE exhibited significantly lower total costs (35.0 % of NaOH-activated slag and 51.7 % of water glass-activated slag) and lower carbon emissions (30.8 % of NaOH-activated slag and 49.8 % of water glass-activated slag) at the same 28 d compressive strength, indicating its strong competitiveness in both sustainability and economy.
基于磷石膏（PG）和粒化高炉矿渣（GBFS）的胶凝材料具有良好的经济性和可持续性，但其强度发展极慢的缺点似乎难以接受。在本研究中，尝试通过引入纳米钙矾石（NE）来推动PG-GBFS的水化，并进一步促进强度发展。研究了1%-5%的NE对PG-GBFS抗压强度、水化过程、溶解行为和微观结构演变的影响。结果表明，NE的掺入显著提高了PG-GBFS的抗压强度。7天时，强度从0MPa增长到7.6-20.2MPa，28天时，强度从22.9MPa提高到45.6-79.0MPa。原因是NE的引入诱导了钙矾石的形成，从而加速了水化过程，促进了骨架网络的发展，导致早期强度更高。此外，NE促进了C-S(A)-H凝胶的形成，进一步细化了孔隙结构，并导致后期强度持续增长。此外，在相同的28天抗压强度下，含5%NE的PG-GFBS的总成本显著更低（分别为NaOH激发矿渣的35.0%和水玻璃激发矿渣的51.7%），碳排放也更低（分别为NaOH激发矿渣的30.8%和水玻璃激发矿渣的49.8%），表明其在可持续性和经济性方面均具有强大的竞争力。
