Performance and microstructural development of MgO-SiO₂ binders under different curing conditions

This study investigated the strength and microstructural development of reactive MgO–SiO2 binder systems under different curing conditions. Rapid strength development associated with accelerated dissolution and hydration involving magnesium silicate hydrate (M-S-H) formation was observed at early ages under elevated temperatures (60°C). Although samples cured under ambient temperatures demonstrated a slow rate of M-S-H formation at early ages, their hydration proceeded over time. Samples cured under sealed conditions achieved 28-day strengths >50MPa because of higher M-S-H contents, higher polymerization and denser microstructures. The content, structure and stability of M-S-H under different conditions determined the overall strength development of MgO–SiO2 binders.