Abstract: Durability of glass fiber reinforced magnesium oxychloride cement (GRMC) was investigated by using the accelerated aging technique and the strand-in-cement (SIC) test method. Development of flexural strength and the deformation characteristics of GRMC samples immersed in hot water of 50 ℃ and 80 ℃ were studied. Micro-phase composition and corrosion degree of glass fibers in the oxychloride magnesium cement matrix were observed by X-ray diffractometer (XRD) and scanning electron microscopy (SEM), and the degradation mechanism was also analyzed. Results show that major factors that cause degradation of GRMC are the performance degradation of the matrix and the looseness of interface structure. While the corrosion of glass fiber, which is closely related to cement matrix performance, also plays a role. Changing in phase compositions of cement matrix cause corrosion of glass fibers, which in turn result in degradation of the material performance. Results of the experiments also show that incensement in the water- resisting of GRMC can obviously improve its performance and durability.

Key words: magnesium oxychloride cement;glass fiber;reinforced;durability;performance degradation