Orientation and distribution of steel fibres in self-compacting concrete

TORRIJOS, M. C.; TOBES, J. M.; BARRAGÁN, B.; ZERBINO, R.

Chennai

Simposio; 7th International RILEM Symposium on Fibre Reinforced Concrete: Design and Applications; 2008

Indian Institute of Technology Madras

The objective of this study is to evaluate the influence of the casting procedure in the distribution and orientation of fibres in a Fibre Reinforced Self-Compacting Concrete (FR-SCC). Two types of hooked end steel fibres of different lengths (50 mm and 30 mm) were used. Beams of 150x150x600 mm were cast in three different ways: filling the moulds from the centre in accorcdance with the EN 14651 Standard method, pouring concrete from one end of the mould after the FR-SCC had flown through a 5 m length and 150 mm diameter tube and finally, filling the moulds placed in a vertical position. Flexural tests were performed by three point loading test in accordance with the EN Standard. To analyse the fibre orientation and distribution, the beams were cut in three different directions. It was observed that fibres acquire a preferential orientation along horizontal planes in FR-SCC, like in conventional vibrated fibre concrete, with a very marked boundary effect. The mechanical response of beams cast with longer steel fibres was strongly affected by the casting procedure, i.e. concrete flow.