Effect of Silica Fume on Early Performance of Precast Concrete with Early Strength Agents

硅灰对掺早强剂预制构件混凝土早期性能的影响

The effect of silica fume on the early performance of precast concrete with an early strength agent was investigated.The ternary compounding technique of silica fume,fly ash and early strength agent were used to examine the compressive strength,heat of hydration,hydration products,and microstructures of the precast concrete.The experimental results showed that the optimum amount of silica fume in the precast concrete was 9%.Silica fume filled the fine pores between the cement particles.However,the cement hydration was mainly influenced by the waterto-cement ratio and cement particle size.As the hydration reaction continued,silica fume provided more nucleation sites,and the characteristic volcanic ash reaction increased both the hydration degree and hydration rate of the early strength agent doped cementitious materials.

为研究硅灰对掺早强剂预制构件混凝土早期性能影响,采用硅灰、粉煤灰和早强剂三元复掺技术,测试分析混凝土抗压强度、水化热、水化产物及微观结构,探究硅灰对掺早强剂预制混凝土构件早期性能影响。试验结果表明:掺早强剂预制混凝土构件中硅灰最适宜量为9%;硅灰填充了水泥颗粒间的细小孔隙,但水泥水化初期主要受水胶比及水泥粒径影响;随着水化反应的不断进行,硅灰提供更多成核表面,特有的火山灰反应使掺早强剂水泥基材料水化程度及水化速率增大。