Sequestration of CO2 in reactive MgO cement-based mixes with enhanced hydration mechanisms

Strength development of reactive MgO cement-based concrete is limited by the low hydration and carbonation of MgO. This study aims to improve the hydration and mechanical performance of carbonated MgO mixes with the introduction of various hydration agents (HAs) at different concentrations. Influence of these HAs on the hydration and carbonation mechanisms under ambient and accelerated curing conditions was evaluated through isothermal calorimetry, TG, XRD and FTIR analyses. Introduction of HAs enabled extensive carbonation and strength development reaching up to ∼60 MPa at 28 days, which was 107% and 53% higher than the corresponding MgO and PC-based control mixes, respectively.