Research on the properties of magnesium oxychloride cement prepared with simulated seawater

Simulated seawater (SW) was used to fabricate magnesium oxychloride cement (MOC) pastes. Compressive strength, water resistance, performance under salt attack, thermal stability, mineral composition and microstructure were studied in detail by using a materials testing system, thermogravimetry and differential scanning calorimetry methods, X-ray diffraction and scanning electron microscopy. The results showed that the compressive strength, strength retention in distilled water and thermal stability of MOC pastes made with simulated SW were slightly lower than those of the control MOC pastes. The main hydration product of both the MOC pastes was 5Mg(OH)₂.MgCl₂.8H₂O. The strength retention of the simulated SW MOC pastes was 11·27% higher than that of the fresh water (FW) MOC pastes after 28 d of immersion in raw brine. The properties of the MOC pastes appeared to be unchanged when manufactured using simulated SW instead of FW. Due to its good performance under salt attack, the MOC pastes mixed with simulated SW show potential as salt pan material.