Monitoring steel fibre orientation in self-compacting cementitious composite slabs during pouring with dynamic X-ray radiography

Abstract

This paper presents a new technique based on dynamic X-ray radiography that can be used to assess fibre orientation during pouring of steel fibre reinforced cementitious composites. Synthetic examples were used to assess the suitability and robustness of the technique, which was shown to provide reliable measurements of fibre orientation even when the signal-to-noise ratio is relatively high. A study was then carried out on the effect of formwork aspect ratio, time/duration of pouring, and rebar placement on the fibre orientation while pouring self-compacting cementitious composite slabs. Results demonstrated the ability of the technique in monitoring the movements of fibres while pouring, and the strong effect of the flow in inducing preferential fibre alignment within the slabs. Fibre orientation was found to vary progressively over time and could take about half of the duration of pouring to fully stabilise.