Theoretical analysis of the moment–curvature relationship of coal gangue concrete beams

At present, there are only a few studies on the application of coal gangue concrete to structural components. To study the moment–curvature relationship of steel-fibre-reinforced coal gangue concrete beams, a simplified calculation method was proposed in this study. The equations were optimised based on current design codes, including theoretical calculations of flexural stiffness, crack width and spacing, cracking moment and ultimate moment. Calculated results were compared with experimental results to verify that the cracking moment and ultimate moment of the beams were slightly lower than those of natural concrete beams. However, the cracking moment, flexural stiffness and ductility of coal gangue concrete beams was increased by incorporating steel fibres. Increasing the rebar ratio also significantly improved the load-carrying capacity, but reduced ductility. The calculated values for moment–curvature were close to the experimental values, proving the optimised calculations have high accuracy and are applicable for predicting the bending behaviour of steel-fibre-reinforced coal gangue concrete beams. This paper provides a theoretical basis for subsequent related research.