Effect of nano calcium carbonate on hydration characteristics and microstructure of cement-based materials: A review

Nano calcium carbonate (NC) is a type of nanomaterial with remarkable properties. It significantly affects the hydration characteristics of cement and the microstructure of cement-based materials when added to these. Based on the related research on the influence of NC on cement hydration characteristics and the microstructure of cement-based materials, this paper summarizes the influence mechanism of NC on the cement hydration process, hydration products, pore structure, and interface transition zone in cement-based materials. It is observed that NC can promote the hydration process of cement as well as the formation of calcium-silicate-hydrate (C–S–H) gels and hydrated calcium carboaluminate through nucleation and chemical reaction. In addition, it can optimize the pore structure and interfacial transition zone of cement-based materials and improve the mechanical properties and durability of these materials. At present, the relevant research conclusions on the influence of NC on cement hydration characteristics and the microstructure of cement-based materials are being debated upon (e.g., regarding the optimal amount of NC and optimal particle size) Therefore, further research is necessary.