摘 要：根据分形几何理论评价超细粉体的活性，探讨纳米 SiO₂ 对水 泥早期水化的影响。用激光粒度分布仪测试水泥试样在早期水化时的 颗粒分布状况， 应用分形理论分析评价了水泥试样的粒度分布特征， 测试、计算了不同试样相应的分形维数。研究结果表明，随水化时间的 增加， 掺入纳米 SiO₂ 的水泥试样的分数维的数值变化的程度更大一 些， 掺入纳米 SiO₂ 的水泥试样水化更快， 进而说明了由于纳米 SiO₂具有更高的火山灰活性而促进了熟料水化更快。 

关键词：纳米颗粒；硅灰；分数维；颗粒分布

Abstract：The superfine powder activity was evaluated by fractal geomet rical theory， and the effect of SiO₂ nano-particles on early hydration of Portland cement was explored. The cement samples were studied with the laser particle sizer. The characteristic of particle size distribution of the cement samples was investigated using fractal theory. The fractal dimen sion of different samples were tested and counted. The results showed that the sample containing with SiO₂ nano-particles had more change in fractal dimension and faster hydration. So the SiO₂ nano-particles with high pozzolanic activity advanced faster hydration of clinker. 

Keywords： nano-particle； silica fume； fractal dimension； particle size distribution