Effect of Coconut Fiber Dosage on Flexural Performances of Magnesium Phosphate Cement

Magnesium phosphate cement (MPC), as a new type of inorganic cementitious material, has the advantages of fast curing speed and high early strength. However, MPC still exhibits poor toughness similar to other cementitious materials. Coconut fiber (CF), a renewable plant fiber, was found to have the potential to improve the toughness of MPC in our previous research. As a result, further research should be completed to investigate the mechanical behaviors of MPC mixed with CF. This paper focused on the effect of CF volume dosage on MPC’s flexural performances. Flexural strength, load-deflection (L-D) relationship, fractural patterns, and flexural toughness were obtained by carrying out a three-point bending test. The results showed that flexural strength first increased and then decreased with increasing CF dosage, and the optimal CF dosage for flexural strength was 3%. Besides, it could be observed from the L-D relationship that the toughness increased continuously with increasing CF dosage. Additionally, the technique of scanning electron microscopy (SEM) was employed to analyze the microstructure of MPC mixed with different CF dosages.