Choi Young-Cheol
Department of Civil and Environmental Engineering, Gachon University, Seongnam 13120, Gyeonggi-do, Republic of Korea.
Materials (Basel). 2025 Jun 12;18(12):2769. doi: 10.3390/ma18122769.
High-volume fly ash cement exhibits drawbacks such as delayed hydration and reduced early-age compressive strength due to the replacement of large amounts of cement with fly ash. In recent years, various studies have been conducted to overcome these limitations by incorporating nanomaterials, such as nano-silica, to promote the hydration of cementitious systems. This study aims to investigate the effect of colloidal nano-silica on the hydration behavior of cement. Cement paste specimens were prepared with varying dosages of colloidal nano-silica to evaluate its influence. To examine the hydration characteristics and mechanical performance, compressive strength tests, isothermal calorimetry, and thermo-gravimetric analyses were conducted. Furthermore, the effect of colloidal nano-silica on the hydration of cement blended with fly ash was also examined. The experimental results revealed that the incorporation of colloidal nano-silica accelerated the hydration reactions in both ordinary and fly ash-blended cement pastes and significantly improved early-age compressive strength. In particular, the 7-day compressive strength of fly ash-blended cement mortar improved by 22.2% compared to the control specimen when 2% colloidal nano-silica was incorporated. The use of colloidal nano-silica appears to be a practical approach for enhancing the early strength of high-volume fly ash concrete, and its broader application and target expansion could contribute to the advancement of a low-carbon construction industry.
高掺量粉煤灰水泥存在一些缺点，例如由于用大量粉煤灰替代水泥，导致水化延迟和早期抗压强度降低。近年来，已经开展了各种研究，通过掺入纳米材料（如纳米二氧化硅）来克服这些限制，以促进胶凝体系的水化。本研究旨在探究胶态纳米二氧化硅对水泥水化行为的影响。制备了不同胶态纳米二氧化硅掺量的水泥净浆试件，以评估其影响。为了研究水化特性和力学性能，进行了抗压强度试验、等温量热法试验和热重分析。此外，还研究了胶态纳米二氧化硅对掺粉煤灰水泥水化的影响。实验结果表明，掺入胶态纳米二氧化硅加速了普通水泥净浆和掺粉煤灰水泥净浆的水化反应，并显著提高了早期抗压强度。特别是，当掺入2%胶态纳米二氧化硅时，掺粉煤灰水泥砂浆的7天抗压强度比对照试件提高了22.2%。使用胶态纳米二氧化硅似乎是提高高掺量粉煤灰混凝土早期强度的一种实用方法，其更广泛的应用和目标拓展可能有助于推动低碳建筑业的发展。
