ABSTRACT
In this paper, the high variability generally associated with Fibre-Reinforced Concrete (FRC) is investigated by evaluating the fibre spatial inhomogeneity in a composite section. A photometric image analysis technique was implemented to quantify fibre inhomogeneity and the results were related to the flexural performance obtained from notched three-point bending tests. The experimental framework considered two different hook-ended steel fibres with different lengths incorporated into a 50 MPa concrete mixture at volume contents ranging from 40 kg/m3 to 120 kg/m3. Spatial distribution is explored by assessing the uniformity of fibre distribution across a section and defining the inter-batch spatial variability as the variation in uniformity. The findings highlight the role of fibre length and fibre dosage on the spatial distribution of fibres and it is revealed that sectional uniformity and inter-batch variability reduces as the number of fibres intersecting the cutting plane increases. Furthermore, the results demonstrate the substantial influence of fibre distribution on the flexural response of SFRC and it is concluded that the variability in flexural strength reduces as the variation in fibre spatial distribution reduces.
