硅灰对水泥-减水剂体系水化早期Zeta电位的影响研究

Influence of silica fume on Zeta potential of early superplasticiser-cement hydration

硅灰作为常用的活性矿物掺合料,在当前配制绿色高性能混凝土中得到了广泛的应用。采用电声法测定了不同掺量的硅灰与不同掺量的减水剂对水泥早期水化Zeta电位的影响,并同时测定水泥水化溶液体系的电导率,以此来判定拥有巨大比表面积的硅灰按照一定比例替代水泥后对水泥-减水剂体系水化早期Zeta电位的影响情况。结果表明:自身Zeta电位呈强负电的硅灰提高了水泥水化早期的Zeta电位值;在对FDN-水泥水化体系的影响中主要表现为降低该溶液体系的Zeta电位的绝对值;而对PCA-水泥水化体系的影响中则主要表现为促进该溶液体系的电导率。

Silica fume, as an activity mineral admixtures of common used, has been widely used in the current producing of green high performance concrete.In this paper, it has measured the Zeta potential values of different dosages of silica fume with different superplasti-cizer amounts to the influence of the cement hydration at early age by the electro-acoustic method,and measured the electrical conductivity in the system of cement hydration solution at the same time.According to the above, it could be the judgment of the influence conditions of Zeta potential in the cement-superplasicizer system after the silica fume which owing huge specific surface area in certain proportion to re- place cement in the early hydration age.The results showed that,the silica fume which showed the negative charge itself could increased the Zeta potential values in cement hydration at early age; The influencing factors mainly presented as decreased the absolute value of the Zeta potential in FDN-cement hydration system;On the contrary, it mainly showed as improved the electrical conductivity in PCA-cement hydration system.