Assessment of fibre orientation in reinforced concrete using Fourier image transform

In this study, ribbon‐shaped amorphous cast‐iron fibres were used to reinforce a concrete matrix. X‐ray photographs have been taken to detect fibres in situ. Their orientation has been investigated by automatic image analysis methods. However, this measurement should not be influenced by the digitization on the square frame of the analyser. For that purpose, the Fourier transform was used rather than the rose of direction method. This analysis revealed the transverse isotropic nature of the spatial arrangement of these fibres, whose axis of revolution corresponds to the concrete casting axis. Such a morphological characterization of the fibre‐reinforced concrete reveals its mechanical behaviour.