硅灰对混凝土抗冻性能及其孔结构的影响

Effect of silica fume on the frost resistance and pore structure of concrete

研究了硅灰对干湿-冻融条件下混凝土的抗压强度和质量损失的影响,利用压汞分析了试验混凝土的孔隙率及孔径分布特征,并计算了混凝土的孔径分形维数。研究表明:随着硅灰掺量的增加,经干湿-冻融循环后混凝土的抗压强度损失率和质量损失率减小,硅灰掺量增加有利于降低混凝土孔隙率、降低平均孔径,大于100 nm的孔数量减少,硅灰的加入使混凝土的孔分形维数增大。

The effect displayed by silica fume on concrete＇s compressive strength and size distribution of test concrete are analyzedthrough MIP, pore fractal dimension is also calculated.It is showed in the research that compressive strength and mass loss of the concrete,which has been through dry-wet thawing circulation, can be lessened by higher proportion of silica fume.Adopting a higher proportion ofsilica fume can also generatelower porosity and average pore size, less pores sized bigger than 100nm.Pore fractal dimension increased atthe effect of adding silica fume.