高温环境下叶蜡石对磷酸镁水泥作用机理分析.

The high-temperature resistance of magnesium phosphate cement (MPC) as an inorganic adhesive for strengthening and repairing building structures has attracted significant attention. In this paper, a pyrophyllite compound magnesium phosphate cement (P-MPC) was prepared. The high-temperature resistance of this material was analyzed through mechanical properties, mass loss rate, microscopic observation, and phase analysis. Results indicate that with increasing pyrophyllite content, the compressive strength retention rate of MPC gradually in creased at elevated temperatures. At 800 °C, the strength retention rate of MPC with 12% pyrophyllite content was 20%, exceeding 6% of the blank control group. Phase composition analysis revealed that the decomposition of hydration product struvite was a key factor leading to the decrease in compressive strength of MPC. Thermogravimetric analysis indicated that the mass loss rate of MPC decreased gradually with increasing pyrophyllite content. Backscattered electron spectrometer (BES) analysis of the microstructure and elemental composition of the blank control group and the experimental group with 12% pyrophyllite content at 200 °C and 800 °C showed that the pyrophyllite maintained good integrity with MPC at high temperatures, indicating that this silicate material can effectively combine with MPCthereby improv its high-temperature resistance. [ABSTRACT FROM AUTHOR]