【摘要】 钢渣和水泥具有相似的矿物组成,可以作为一种潜在的胶凝材料,然而钢渣掺量较高时并不利于混凝土早期性能的发展。以钢渣质量分数为30%的钢渣水泥基胶凝材料为研究对象,探讨纳米SiO₂对其早期性能的影响。主要通过测量流动度、凝结时间和抗压强度评估物理力学性能,并利用微量热分析、X射线衍射（XRD）、差热分析（DSC-TG）等方法对掺有纳米SiO₂的钢渣水泥基胶凝材料的水化过程和水化产物进行分析。结果表明,当纳米SiO₂掺入的质量分数为3%时,纳米SiO₂可充分发挥火山灰活性,消耗大量Ca（OH）₂,同时由于纳米SiO₂颗粒的结晶成核作用和微集料填充作用,促进了钢渣和水泥的水化,水化初期的放热速率有所提高,从而提高钢渣水泥基胶凝材料的力学性能,28 d的抗压强度提高了14.0%。更多还原

【Abstract】 Steel slag has similar mineral composition with cement, which can be used as a potential cementitious material. However, the high content of steel slag is not conducive to the development of early properties of concrete. Steel slag/cement-based cementitious materials with 30%（by weight） steel slag as the research object were used to discuss the influence of nano-SiO₂ on its early properties. Physical and mechanical properties were evaluated by measuring fluidity, setting time, and compressive strength. The hydration process and hydration products of steel slag/cement-based cementitious materials with nano-SiO₂ were analyzed by micro-thermal analysis, X-ray diffraction（XRD）, and differential scanning calorimetry（DCS-TG）. Results show that when the mass fraction of nano-SiO₂ is 3%, nano-SiO₂ consumes large amounts of Ca（OH）₂ due to its high pozzolanic activity. Meanwhile, due to the crystallization nucleation and micro-aggregate filling effect of nano-SiO₂ particles, the hydration of steel slag and cement is promoted, and the heat release rate at the initial stage of hydration is improved, thus improving the mechanical properties of steel slag/cement-based cementitious materials, and the 28 d compressive strength increases by 14.0%.更多还原