Use of fines from waste concrete as an admixture in new concrete

Abstract

Recycling waste concrete is a practice that is advancing more and more in search of more eco-efficient practices in the production of cementitious materials. Whether when obtained fromsieving the primarily crushed waste concrete or from secondary grinding of recycled particlesunder 2-4 mm, the recycled powder finds the most valorisation difficulties. In this Chapter,studies in the literature covering the use of recycled powder are commented. Special attentionis paid to the properties of the recycled powder such as particle size distribution, internalporosity, and cement hydrates content, and their correlation with properties of pastes, mortarand concrete produced with recycled powder. Beneficiation procedures including additionalgrinding and thermal activation, as well as their limitations, are commented. Finally, thepotential application of recycled powder in the production of self-compacting concrete iscommented, including some recommendations for this valorisation strategy.