Structural shear behaviour of recycled concrete with silica fume

This paper is the outcome of the second stage of studies carried out on the structural behaviour of recycled concrete. The first stage determined, using beams specimens, the shear behaviour of recycled concrete with which 50% of the coarse aggregate was replaced by recycled coarse aggregate (obtained from concrete demolition waste). This stage revealed minor differences (recycled concrete – conventional concrete) in ultimate loads and these differences were found to increase when cracking was taken into account. In this study, it was determined that the addition of 8% silica fume to recycled concrete (recycled concrete with silica fume) improved this behaviour. Moreover, the use of this material in recycled concrete produced changes in its structural behaviour similar to those induced in conventional concrete (conventional concrete with silica fume). Finally, experimental results were compared using current codes and it had been seen that all of them were conservative so t can be used for the shear design of recycled concrete beams with silica fume.