Development and applications of MgO-activated SiO2 system—achieving a low carbon footprint：A review

Abstract

The MgO-activated SiO₂ system demonstrates potential for a low carbon footprint throughout its lifecycle and is characterized by favorable mechanical properties, low alkalinity, and a high specific surface area, which shows promise in replacing traditional silicate cement in certain applications. The current system faces challenges such as slow early hydration rate, low early strength, and inadequate volume stability, which impede its further development and application. The MgO-activated SiO₂ system was improved and optimized through multiple tests using carbonation (CO₂ gas/NaHCO₃ solution), nanomaterials (whiskers), and fiber (organic/inorganic fiber) composite reinforcement. This paper provides an overview of the hydration mechanism of the MgO-activated SiO₂ system, explores modifications and control measures based on this mechanism, and discusses the potential applications and future development of the MgO-activated SiO₂ system.