关键词: 硫氧镁水泥;氯氧镁水泥;力学性能;耐水性;物相组成;微观结构

Abstract: In order to improve the performance of the magnesium oxychloride cement.Combine magnesium oxysulfate cement with magnesium oxychloride cement, mixed system was prepared.The setting hardening characteristics and water resistance were studied by testing setting time, compressive strength and flexural strength.Microstructure, ingredient distribution and phase composition were analyzed by means of XRD, SEM and EDS.The experimental results demonstrate that the setting time increase with the increase of magnesium chloride content when the magnesium chloride content is less than 70％.The compressive strength of mixed system decreases and flexural strength increases slightly, it shows better water resistance after immersion water 28 d.The data of XRD, SEM and EDS show that there is no strong continuous structure between crystal to make mechanical properties of mixed system reducing.The main reason of improving water resistance is the change of microstructure of hydration products after soaking.

Key words: magnesium oxysulfate cement;magnesium oxychloride cement;mechanical property;water resistance;phase composition;microstructure