Stone consolidation with SiO2 nanoparticles: Effects on a high porosity limestone

This study deals with the effect of a water colloidal suspension of nanosilica applied as a consolidant on a porous limestone. The stone performances were investigated by several analyses and tests. They fulfilled basic requirements such as consolidating effectiveness and compatibility with the original colour and water transport properties. A point of weakness was found in the behaviour under the salt crystallisation test, showing a decreased durability for the treated stone. The modification of the porous structure accounts for this result, suggesting that the distribution of the nanoparticle fillers into the stone substrate should be improved. (C) 2019 Elsevier Ltd. All rights reserved.