【摘要】 本工作通过测定不同硅灰掺量下,掺有无碱速凝剂水泥浆体的凝结时间、抗压强度、水化放热、早期体积变化、喷射回弹率等性能,研究了硅灰对掺有无碱速凝剂水泥浆体性能的影响。结果表明,掺加适量硅灰可以缩短掺有无碱速凝剂水泥浆体的凝结时间,提高喷射混凝土的抗压强度,降低喷射混凝土的回弹率,同时可以促进水泥水化。此外,根据水泥浆体早期体积变化和水化放热特点,可以将掺有无碱速凝剂水泥浆体的早期水化进程划分为四个阶段,即溶解-结晶期、晶体生长期、水化加速期和稳定期,硅灰对掺有无碱速凝剂水泥浆体的早期水化的影响主要表现在晶体生长期和水化加速期。更多还原

【Abstract】 This study evaluates the effect of silica fume on the properties of cement paste with alkali-free accelerator. Setting times,compressive strength,hydration heat emission,early volume change and rebound rate of accelerated cement paste with different silica fume dosage were measured. The results show that a proper dosage of silica fume can shorten the setting time and increase the compressive strength of the accelerated cement paste,decrease the rebound rate of shotcrete and promote the cement hydration. Moreover,according to the characteristics of the early volume change and hydration heat emission curve,the hydration process of the cement paste with alkali-free accelerator can be divided into four periods,including dissolution-crystallization period,crystal growth period,acceleration period and stable period. The effect of silica fume on the properties of cement paste with alkali-free accelerator mainly manifest in crystal growth period and acceleration period.更多还原