Wang Shiheng, Zhao Peng, Tian Yaogang
School of Materials Science and Engineering, Chang'an University, Xi'an 710061, China.
Materials (Basel). 2025 Feb 28;18(5):1105. doi: 10.3390/ma18051105.
In order to improve the dispersion state of silica fume (SF) in cement concrete, accelerate the hydration rate of high-strength steam-cured cement concrete, and reduce production costs. In this paper, SF was made into a wet-ground silica fume (WSF) suspension solution through a wet grinding process and was applied to high-strength steam-cured concrete to replace the SF so as to improve the difficult dispersion of the inner SF and enhance the compressive strength of concrete. The physical and chemical properties of WSF were studied by XRD, SEM, and ZETA potential, and its effects on the mechanical properties, hydration development, and microstructure of cement concrete were studied using XRD, SEM, TG, BET, and NMR. The results show that SF mixed with water is transformed into a kind of suspension solution by wet grinding. After adding WSF, the compressive strength of concrete at 1 d increases when the substitution of WSF increases. Compared with SF-0, the 1 d compressive strength of SF-1 and SF-2 increased by 9.2% and 12.9%. When the WSF substitution was greater than 50%, the compressive strength of concrete did not improve significantly; the 1 d compressive strength of SF-3 and SF-4 is 14.3% and 15.4% higher than SF-0. With the increase in WSF substitution, the porosity of concrete at 1 d decreases, and the structure becomes denser. XRD, TG, and NMR analyses show that WSF can promote the hydration development of cement to form a C-S-H gel. As the amount of WSF substitution increases, its effect on the cement hydration reaction increases first and then tends to be flat.
为了改善硅灰（SF）在水泥混凝土中的分散状态，加快高强蒸汽养护水泥混凝土的水化速率，并降低生产成本。本文通过湿磨工艺将硅灰制成湿磨硅灰（WSF）悬浮液，并将其应用于高强蒸汽养护混凝土中以替代硅灰，从而改善内部硅灰分散困难的问题，并提高混凝土的抗压强度。通过XRD、SEM和ZETA电位研究了WSF的物理和化学性质，并使用XRD、SEM、TG、BET和NMR研究了其对水泥混凝土力学性能、水化发展和微观结构的影响。结果表明，硅灰与水混合后通过湿磨转化为一种悬浮液。加入WSF后，随着WSF替代量的增加，混凝土1 d龄期的抗压强度增加。与SF-0相比，SF-1和SF-2的1 d抗压强度分别提高了9.2%和12.9%。当WSF替代量大于50%时，混凝土的抗压强度没有显著提高；SF-3和SF-4的1 d抗压强度比SF-0分别高14.3%和15.4%。随着WSF替代量的增加，混凝土1 d龄期的孔隙率降低，结构变得更加致密。XRD、TG和NMR分析表明，WSF可以促进水泥的水化发展以形成C-S-H凝胶。随着WSF替代量的增加，其对水泥水化反应的影响先增大后趋于平稳。
