Rheology of self-compacting concrete containing silica fume and recycled aggregates

AbstractRheology of Self-Compacting Concrete (SCC) containing selected silica fume dosages (0% (control mix), 5%, 10% and 15%) in a binary binder has been investigated using the flow-curve test protocol implemented on a co-axial cylinder rheometer. At each silica fume dosage, coarse recycled concrete aggregate volumetric replacement levels were 0%, 50% and 100%. Calibration of selected flow models with the measured flow data showed that rheology transitioned from shear thickening to shear thinning as the silica fume dosage increased from 0% to 15%, other mix constituents remaining unchanged. Similar flow behaviour was noted in the SCCs made with the recycled concrete aggregates (SCRACs) across all replacement levels though for a given silica fume dosage, degree of shear thinning decreased with increasing contents of the coarse recycled aggregates. The experimental results have been used to propose a workability box containing bounds for acceptable rheology of the SCCs and the SCRACs.Keywords: Rheologyself-compacting concreterecycled concrete aggregatesilica fumeshear thinningshear thickening AcknowledgementsThe authors would like to thank technical staff/Lab staff of structural Engineering Division, Department of Civil Engineering, Indian Institute of Technology Roorkee for their support to carry out the experimental work presented in this article.Data availabilityThe data that support the findings of this study are available on request from the first author, [RBS].Disclosure statementAll authors declare that there is no conflict of interest.