Effects of colloidal nanoSiO2 on the hydration and hardening properties of limestone calcined clay cement (LC3)

Abstract

This research investigates the influence of colloidal nanosilica (CNS) on the hydration and hardening properties of Limestone Calcined Clay Cement (LC3).. The sulfation degree for LC3 was first optimized based on the hydration heat, and the results suggested that gypsum increases the cumulative heat release during the hydration process of LC3, with a dosage of 2% by weight gypsum leading to the highest heat release. The effects of CNS on hydration reaction, fluidity, mechanical properties and microstructure of LC3 were then investigated. According to the results obtained from isothermal calorimetry and thermogravimetric analysis, CNS can considerably accelerate the reaction rate of the LC3 system. 3% and 5% by weight CNS can significantly improve the compressive strength of LC3 blends, especially at early ages of 3 and 7 days. The findings from this study lead to a better understanding of the modification effects of CNS on LC3 which subsequently provides an insight into regulation mechanism of CNS on LC3.