Influence of substrate pore structure and nanolime particle size on the effectiveness of nanolime treatments

Nanolime is a promising consolidation treatment for the conservation of historic structures thanks to its high compatibility with carbonate-based substrates. Nanolime products can effectively reduce the porosity and restore the mechanical properties of treated surfaces. Whilst the popularity of nanolime has been growing, its consolidation mechanism still needs to be fully understood when applied to porous substrates. The aim of this paper is to determine the influence of nanolime particle size and substrate pore structure on the effectiveness of nanolime treatments. Results suggest that nanolime products with larger particle size tend to close predominantly large sized pores, while nanolime with smaller particle size tends to fill both large and small pores equally. These results suggest that for a consolidation treatment, the nanolime product must be chosen taking into consideration the substrate pore structure.