Improvement and mechanism of the mechanical properties of magnesium ammonium phosphate cement with Chopped fibers

In order to improve the mechanical properties and brittleness of magnesium ammonium phosphate cement (MAPC), polypropylene fibers and EB fibers were added to the MAPC. The optimum fibers content was determined by evaluating the fluidity, flexural strength and compressive strength of the fibers-laden MAPC. The mechanisms of polypropylene fibers-based MPAC and EB fibers-based MAPC mortar samples were determined via micro-morphology analysis. The results show that the optimum polypropylene fibers and EB fibers contents range from 0.6%-0.9%, and that inclusion of both leads to an improvement in the strength of MAPC mortar. There exists a strong adhesive force between EB fibers and cement, which can prevent glass fibers from being pulled out of cement when it undergoes tensile stress. The polypropylene fibers, however, become eroded and weakened within the MAPC, which leads to a decline in adhesive force, and exposure of polypropylene fibers whenever the cement is subject to tensile stress. (C) 2020 Elsevier Ltd. All rights reserved.