Preparation and mechanical characterization of multi-functional high-ductility engineered magnesium oxysulfate cement-based composites

Aiming at the integrated requirements of building energy saving and thermal insulation reinforcement in reinforcement engineering, the technology of preparing multi-functional high-ductility engineered magnesium oxysulfate cement-based composites (MOSC-ECC) by magnesium oxysulfate cement (MOSC) was proposed; the mechanism of industrial waste fly ash (FA) to improve the ductility of MOSC-ECC was explored; the effects of FA on the density, thermal conductivity and water resistance of MOSC-ECC were studied; the phase composition and microstructure of the hydration products of MOSC-ECC were analyzed. The results show that the incorporation of FA instead of light-burned magnesium oxide (LB-MgO) powder of equal mass can effectively reduce the cracking strength, fracture toughness, density and thermal conductivity of the matrix, and improve the ductility and multiple cracking ability of MOSC-ECC. The incorporation of hydrophobic agent made MOSC-ECC have excellent water resistance. The findings of this study provide useful knowledge for realizing the integrated design of thermal insulation and reinforcement of structures, which is of great significance for promoting the engineering application of ECC and the promotion of energy-saving green building materials.