Directionally distributed steel fibre-reinforced concrete (SFRC) cannot be widely applied due to the limitations of current construction technology, which hinders research on its mechanical properties. With the development of new construction technologies, such as self-compacting concrete or 3D printing, directionally distributed SFRC has found new developmental opportunities. This study tested, compared, and analysed the basic mechanical properties of ordinary concrete, randomly distributed SFRC, and directionally distributed SFRC. The differences between the damage patterns parallel and perpendicular to the direction of the steel fibres were evaluated in directionally distributed SFRC. When the fibre volume fraction is high and the compression is applied perpendicular to the fibre direction, as the loading increases, the transverse deformation of the specimen is constrained by the fibres. When the compression is applied parallel to the fibre direction, the fibre cannot effectively constrain the transverse deformation of the specimens. When the volume fraction of directionally distributed steel fibres was 1.6%, the elastic modulus of the directionally distributed steel fibres was 39% higher than that of ordinary concrete. Comparison of the experimental values of the elastic modulus with those estimated by existing calculation methods revealed that a modification of the current calculation theories may be required to calculate the changes in the elastic modulus of directionally distributed SFRC with a high volume fraction of steel fibres.

Directionally distributed steel fibre-reinforced concrete has been proposed as a novel concrete because of its high tensile strength and crack resistance in specific directions. Based on the existing studies of the effect of the fibre direction on the mechanical properties of fibre-reinforced concrete, the authors in this paper performed further studies of the mechanical properties of directionally distributed steel fibre-reinforced concrete by conducting split tensile and bending tests. The split tensile strength of the directionally distributed fibre-reinforced concrete clearly exhibited anisotropy. The split tensile strength perpendicular to the fibre direction was much higher than that parallel to the fibre direction. The split tensile strength perpendicular to the fibre direction was almost twice the tensile strength of plain concrete. The flexural performance of directionally distributed fibre-reinforced concrete in the fibre direction significantly improved compared to that of randomly distributed fibre-reinforced concrete. Specifically, the flexural strength increased by as much as 97%. Gravity resulted in a deviation in the tensile properties of concrete prepared by manually and directionally placing fibres in a layered casting process. The test results can be utilised in subsequent concrete designs. The conclusions reached in this paper provide comprehensive mechanical design parameters for the application of directionally distributed fibre-reinforced concrete.