Recycling alkali activated slag into artificial aggregate: Influence of particle size distribution of the starting material on granulation

Abstract

Wet granulation is a potential method to develop artificial aggregates. In this paper, the granulation of recycled alkali-activated slag powders with different particle size (d50 ranging between 12.9–127.7 μm) distributions were investigated in order to find how these affect on the engineering properties of the artificial aggregates. Blast furnace slag was added as co-binder in 10–30 wt. % during the granulation process and to enhance the properties, especially mechanical strength. The results show that the particle size of the raw material significantly affects the engineering properties of the produced aggregates, such as the crushing force (19–131.8 N), bulk density, water absorption, porosity and microstructure of the granules. The results show that granulation is a promising method to recycle alkali-activated materials as lightweight aggregates to replace natural aggregates. Graphical Abstract