Mechanical properties of fiber and nano-Al2O3 reinforced magnesium phosphate cement composite

•The mechanical properties of magnesium phosphate cement (MPC) enhanced by adding fiber and nano-Al2O3 were investigated.•The empirical formulae for predicting the compressive strength and splitting tensile strength of FNRMC were proposed.•The modification mechanisms of nano-Al2O3 on the MPC were revealed by XRD and SEM. In this paper, the mechanical properties of magnesium phosphate cement (MPC) was enhanced by adding fiber and nano-Al2O3. The effects of fiber and nano-Al2O3 on the workability, compressive strength and flexural toughness of MPC were studied. The variables of the experimental investigation included the types of fiber, fiber volume fraction, nano-Al2O3 substitution rate and curing time. The experimental results showed that the workability and the mechanical properties of the MPC could be improved by adding nano-Al2O3. The workability decreased gradually with increasing fiber content, while the compressive and tensile strength gradually increased. Among different types of fiber, the micro-steel fiber (MSF) had the most significant effect on the improvement of flexural toughness. Based on the analysis of experimental data, empirical formulae for predicting the compressive strength and splitting tensile strength of fiber and nano-Al2O3 reinforced MPC composite (FNRMC) were proposed. In addition, the modification mechanisms of nano-Al2O3 on the MPC were revealed by XRD and SEM for microscopic phase tests.