多元组分对磷酸钾镁水泥高温下性能劣化的影响OA

Magnesium potassium phosphate cement(MKPC)is prone to dehydration and decomposition of its hydration products under high-temperature exposure,which leads to strength degradation and volumetric shrinkage,thereby limiting its engineering applications in high-temperature environments.To address this issue,an orthogonal experimental design was employed to systematically investigate the effects of the water-to-binder ratio and the content of silica sol,expanded vermiculite,and glass beads on the performance degradation of MKPC under high-temperature.The underlying mechanisms were further elucidated through microstructural analyses using XRD,SEM,and TG-DSC.The results indicate that expanded vermiculite and glass beads can effectively mitigate strength loss and volumetric shrinkage under high-temperature conditions and are the key components for suppressing the performance degradation of MKPC under high-temperature.When the water-binder ratio is 0.25 and the dosages of silica sol,expanded vermiculite and glass beads are 5%,15% and 12%(mass fractions),respectively,MKPC exhibits excellent strength stability and volume stability at high temperatures.Microstructural analyses reveal that expanded vermiculite promotes the formation of refractory silicate phases to construct a stable high-temperature skeleton,while glass beads soften to form a glassy phase that enhances particle bonding.The synergistic effect of these two components effectively improves the high-temperature structural stability of MKPC from both phase composition and microstructural perspectives.