Flexural behavior of steel fiber-reinforced coal gangue aggregate concrete beams

The flexural behavior of steel fiber-reinforced coal gangue aggregate concrete (SFCGC) and steel fiber-reinforced ordinary concrete (SFOC) beams were investigated in this study. 11 specimens were tested using four-point bending tests to investigate the effect of coal gangue replacement rate (CGRR) (0%, 50%, 100%), steel fiber volume content (SFVC) (0%, 0.5%, 1%, 1.5%), rebar ratio (0.6%, 1.17%, 1.94%), and beam height (200 mm, 300 mm) on the beam flexural performance. The failure modes, flexural capacities, flexural stiffness, ductility, and energy dissipation coefficient of the specimens were analyzed. In addition, the stress-strain curve of SFCGC was obtained by axial compressive tests in this study. A equations for the stress-strain relationship of SFCGC beams were obtained by data fitting. a finite element model (FEM) of SFCGC beams was established in ABAQUS. A self-programmed Python script was used to create the steel fiber model in FEM of an SFCGC beam, in which steel fibers were distributed randomly and discretely to investigate the strengthening effect of steel fibers on SFCGC beams. Finally, a comparative analysis shows good agreement in the load-deflection curves and trans-verse strain obtained from simulations using the established FE model and tests.

Automated summary

This study investigates the flexural behavior of steel fiber-reinforced coal gangue aggregate concrete (SFCGC) and steel fiber-reinforced ordinary concrete (SFOC) beams. The effects of coal gangue replacement rate, steel fiber volume content, rebar ratio, and beam height on the beam flexural performance were studied. The specimens' failure modes, flexural capacities, flexural stiffness, ductility, and energy dissipation coefficient were analyzed. A finite element model was established to investigate the strengthening effect of steel fibers on SFCGC beams. Comparisons between simulations and tests show good agreement in the load-deflection curves and transverse strain.