Fluidity and mechanical properties of magnetic-field-enhanced steel fibre reinforced coral mortar

Coral sand concrete is a sustainable building material in island engineering with unique fluidity and hardened strength. In this study, a numerical method based on Engineering Discrete Element Method (EDEM) was developed to investigate the fluidity and mechanical properties of steel fibre reinforced coral mortar (SFRCM) and steel fibre reinforced ordinary mortar (SFROM) with/without an external magnetic field. The simulated result is in agreement with experimental results, and the fluidity of SFRCM is lower than that of SFROM, but with a 30 % increased bending strength. Moreover, as the magnetic flux density increases, the bending strengths of SFRCM and SFROM increase by a maximum of 10.6% and 15.4 %, respectively. The effect of the magnetic field direction on the fluidity of steel fibre mortar depends on the interval between steel bars. When the interval is small, a magnetic field aligned with the flow direction can improve the fluidity of steel fibre mortar, with the Lflow distance increasing by 8.1 %. When the interval is larger, a magnetic field perpendicular to the flow direction can improve the fluidity of steel fibre mortar, with the L-flow distance increasing by up to 13.4 %. Regardless of the interval, a magnetic field aligned with the flow direction can increase the gap passing ability of steel fibre mortar, with the maximum increase in the gap passing coefficient G of 8.0 %.