Modeling on the hydration and leaching of eco-friendly magnesium oxychloride cement paste at the micro-scale

Magnesium oxychloride cement (MOC) has been considered as a kind of eco-friendly cement in view of its significantly low calcination temperature and large capacity of carbon dioxide sequestration, compared with ordinary Portland cement (OPC). In this work, a computer model is established to simulate the hydration and leaching of MOC paste at the micro-scale. The composition of MOC paste in the ultimate hydration is investigated based on the thermodynamic method, and pore structure obtained from the computer simulation is compared with the one from experiments and literature, respectively. The simulated leaching results show that the original solid phase skeleton of MOC paste decomposes into magnesium hydroxide crystals. It is demonstrated that the simulation results are in good agreement with experimental data from literature and the proposed simulation can provide an effective method to reveal the hydration and leaching mechanism of MOC paste. (C) 2019 Elsevier Ltd. All rights reserved.