Literature review on steel fibre, silica fume and fly ash: improving methods for recycled and multiple recycled aggregate concretes

If all concrete is to be recycled in a future scenario, recycled concrete will be needed. Usually concrete recycling causes loss of properties, but this does not have to be truth for all the mixtures. This paper shows a comprehensive knowledge about the improving methods used to keep the properties of the recycled aggregate concrete (RAC). In the reviewed literature several kinds of RAC were tested with various replacement ratios. The effect of adding steel fibres, silica fume or fly ash to the mixture were also examined both separately and together. Most of the experiments demonstrated excellent mechanical properties of the RAC compared with ordinary concretes. Based on these results the ideal RAC composition can be deduced and a future can be imagined when concrete can be recycled multiple times (MRAC).