Effect of the pore network and mineralogy of stones on the behavior of alkoxysilane-based consolidants
B. Sena da Fonseca, A.P. Ferreira Pinto, Alexandra Rodrigues, Susana Piçarra, Carlos A. Santos, M.F. Montemor
Abstract
This study aims at assessing the role of stone porous network and mineralogy on the behavior of three partially condensed alkoxysilane-based consolidants, catalysed by different routes. Consolidants were applied on two porous stones of similar strength and with significant presence in built heritage (limestone and sandstone). The potential of the consolidants to improve the stone cohesion was found to be primarily affected by its catalytic route, amount of dry residue and pore size distribution of the stone. The influence of the mineralogical composition of the substrates was secondary when compared with the impact of these factors. The consolidants tends to deposit into smaller pores. Therefore, relevant strength increments could be expected on stones with a wide range of pore sizes (e.g. sandstones) even when treated with consolidants with poor bridging and filling abilities. Despite having quite different characteristics, the consolidants showed potential to increment the cohesion of calcitic and silicate stones, without promoting significant pore occlusion.