偏高岭土、硅灰复掺对水泥混凝土强度与微观结构影响研究

Study on the Influence of Metakaolin and Silica Fume on the Strength and Microstructure of Cement Concrete

采用纯水泥混凝土为基准参照,研究偏高岭土、硅灰、水泥不同比例复掺对水泥混凝土强度、孔隙结构及孔径分布、微观结构形貌的影响。结果表明,对比纯水泥混凝土,内掺入10%硅灰的水泥混凝土抗压强度提高了66.8%、抗折强度提高50%;且大幅度减小了混凝土的孔隙率、平均孔隙直径、最可几孔径、临界孔径,孔隙结构与孔径分布明显改善。当硅灰和偏高岭土分别按10%内掺到水泥混凝土中,抗压强度增加了96.9%,抗折强度增加了57.9%,无害孔和少害孔的比例进一步提高,水化产物结构非常致密,孔隙极小,水泥混凝土抗压强度、抗折强度最大。

Using the pure cement concrete as reference,the influences of metakaolin,silica fume and cement mixed in different proportions on the strength,pore structure,pore size distribution and microstructure of cement concrete were studied.The results show that compared with pure cement concrete,the compressive strength of cement concrete mixed with 10%silica fume is increased by 66.8%,and the flexural strength is increased by 50%.Moreover,the porosity,average pore diameter,maximum pore diameter and critical pore diameter of concrete are greatly reduced,and the pore structure and pore diameter distribution are obviously improved.When silica fume and mekaolin are respectively added into cement concrete by 10%,the compressive strength is increased by 96.9%,the flexural strength is increased by 57.9%,and the proportion of harmless and less harmful holes are increased further.Hydration product structure is very dense with very small pores,so the compressive strength and flexural strength of the cement concrete is the largest.