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

[Display omitted] • Quarry waste added to air lime mortars at 5% and 15% w/w with respect to lime. • Ball milling was applied to the waste to reduce its particle size to the nanoscale. • Mortars with 15% w/w nano-sized waste showed improved carbonation and strength. • Enhancement of carbonation reactions achieved at ambient conditions. 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 CO 2. 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 CO 2 through the mortar pore structure and the improved CO 2 uptake of the nano-sized waste additive. [ABSTRACT FROM AUTHOR]