Investigation of fibre distribution and orientation in SFRC specimens and their influence on flexural properties

The distribution and orientation of fibres were qualitatively estimated using statistical methods, and finite element analysis was conducted to evaluate the flexural behaviours based on these characteristics. The results demonstrate that the fibres disperse well in the concrete matrix when the water-to-binder ratio is 0.35, and the concrete mixture is prepared by sequentially adding coarse/fine aggregates, powder materials, water and steel fibres. In contrast to the order of fibre addition, the water-to-binder ratio significantly influences the fibre distribution coefficient and orientation factor. A water-to-binder ratio of 0.35 results in a higher orientation factor ( g h ) of 0.7. Furthermore, statistical analysis reveals that the orientation of fibres on the cutting section follows a Gaussian distribution, with the peak occurring at approximately 40° to 50°. Finite element analysis revealed that the orientation distribution of fibre affects not only the flexural strength, more significantly, the post-cracking flexural stiffness.