The effect of fibres in the rheology of self-compacting concrete

Resumen

The successful use of self-compacting concrete (SCC) in the construction industry is based on the simplification of pouring procedures, as it fills the formwork merely by the action of its own weight. However, the presence of fibres might undermine the fresh-state properties and, hence, minimise the advantages obtained from use of SCC. From the point of view of fibre reinforced concrete (FRC), the flow of SCC enhances the positioning of the fibres and therefore the residual tensile strength of the composite material. Consequently, study of the rheology of SCC-FRC permits the characterisation and classification of the mix and provides a remarkable tool for design. That is to say, it is essential in analysing fresh state not only by conventional slump flow tests but also by associating such results with those obtained by a rheometer. The significance of this research lies in the comparison of the fresh-state results obtained through slump flow and V-funnel tests with those from a BT-Rheometer, using two types of SCC and both steel and polyolefin fibres. The results show the remarkable influence of the type of fibres and limitations of measurement in terms of physical parameters. This provides relevant information for future applications of the fresh state of FRC-SCC whether using steel or polyolefin fibres.