Microstructural characterization of basalt fiber reinforced magnesium phosphate cement supplemented by silica fume

This research studied the high-temperature resistance and water resistance of magnesium phosphate cement mortar containing different proportions of basalt fiber and silica fume. The improvement mechanism was discussed with several microstructural investigation techniques. It was noticed that increase in the content of silica fume and basalt fiber improved the water and high-temperature resistance of mortar composites. Performance of MPC mortar composite containing 10% silica and 0.5% basalt fiber was superior to other composites showing the water and temperature resistance coefficient of 1.16 and 0.5 respectively. Mass loss results of samples exposed to elevated temperature and those calculated from the thermogravimetric analysis were in similar range of 10 to 12%. Results from mercury intrusion porosimeter indicated that porosity of mortar composites was progressively decreased from 27.4% to 21.05% by increasing the contents of silica fume and basalt fiber. Finally, microstructural analysis of paste samples revealed that additional hydration products were formed beside the main reaction product struvite which supported the enhanced performance of MPC composites due to inclusion of silica fume and basalt fiber.