Determination of dominant fibre orientations in fibre-reinforced high-strength concrete elements based on computed tomography scans

Computed tomography (CT) is a nondestructive technique, based on absorbing X-rays, that permits the visualisation of the internal structure of materials in micron-range resolution. In this paper, the CT scan is used to determine the position and orientation of the fibres in steel fibre-reinforced high-strength concrete elements. The aim of this paper was to present a numerical procedure, automated through a MATLAB routine specially developed by the authors, which enables, fast and reliable, to obtain the orientation of each and every one of the fibres and their centre of gravity. The procedure shown is directly extrapolated to any type of fibre-reinforced material, only if there is a wide difference between density of fibres and density of matrix. The mathematical basis of this procedure is very simple and robust. The result is a fast algorithm and a routine easy to use. In addition, the validation tests show that the error is almost zero. This algorithm can help the industry to implement the technology of CT in the protocols of product quality control.