Kang Sung-Hoon, Hong Sung-Gul, Moon Juhyuk
Department of Architecture and Architectural Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea.
Department of Civil and Environmental Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea.
Materials (Basel). 2020 Sep 3;13(17):3901. doi: 10.3390/ma13173901.
Silica fume (SF) is a key ingredient in the production of ultra-high performance fiber-reinforced concrete (UHPFRC). The use of undensified SF may have an advantage in the dispersion efficiency inside cement-based materials, but it also carries a practical burden such as high material costs and fine dust generation in the workplace. This study reports that a high strength of 200 MPa can be achieved by using densified SF in UHPFRC with Portland limestone cement. Additionally, it was experimentally confirmed that there was no difference between densified and undensified SFs in terms of workability, compressive and flexural tensile strengths, and hydration reaction of the concrete, regardless of heat treatment, because of a unique mix proportion as well as mixing method for dispersing agglomerated SF particles. It was experimentally validated that the densified SF can be used for both precast and field casting UHPFRCs with economic and practical benefits and without negative effects on the material performance of the UHPFRC.
硅灰（SF）是超高性能纤维增强混凝土（UHPFRC）生产中的关键成分。使用未压实的硅灰在水泥基材料内部的分散效率方面可能具有优势，但它也带来了实际负担，如材料成本高和工作场所产生细粉尘。本研究报告称，在含有波特兰石灰石水泥的UHPFRC中使用压实硅灰可实现200MPa的高强度。此外，通过实验证实，由于独特的配合比以及用于分散团聚硅灰颗粒的搅拌方法，无论是否进行热处理，压实硅灰和未压实硅灰在混凝土的工作性、抗压和抗折强度以及水化反应方面均无差异。实验验证了压实硅灰可用于预制和现场浇筑的UHPFRC，具有经济和实际效益，且不会对UHPFRC的材料性能产生负面影响。
