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 degrees 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 >50 MPa 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. (C) 2017 Elsevier Ltd. All rights reserved.