Improving the carbonation of air lime mortars at ambient conditions via the incorporation of ball-milled quarry waste

Abstract The carbonation of air lime mortars modified by the addition of 5% and 15% w/w (in partial replacement to lime) quarry waste, rich in Ca-, Mg- and Fe-silicate minerals, is hereby investigated. Ball milling was initially applied to the waste to reduce its particle size to the nanoscale and increase its reactivity towards CO2. The incorporation of the nano-sized waste at 15% w/w resulted in mortars with denser microstructure and higher compressive strength. This is attributed to the enhanced diffusion of atmospheric CO2 through the mortar pore structure and the improved CO2 uptake of the nano-sized waste additive.