Long-term effectiveness, under a coastal environment, of a novel conservation nanomaterial applied on sandstone from a Roman archaeological site

Abstract

Abstract Water is the main factor of degradation in most stone monuments and buildings, and especially in those located next to the sea, since it acts as a vehicle for decay agents. The continuous exposure of the Baelo Claudia Roman archaeological site to marine aerosol has produced severe weathering. The aim of this study was to assess the performance of a novel consolidant/hydrophobic nanomaterial applied on sandstones from this archaeological site. The product durability was evaluated for three years of exposure at the archaeological site. For comparison, two commercial products (a consolidant and a hydrophobic product) were also evaluated. The obtained results showed that the product synthesised in our laboratory maintained the consolidant and hydrophobic properties, after three years of exposure, due to the production of a homogeneous coating with a penetration depth of 20 mm. The commercial consolidant was completely cracked and the hydrophobic product generated a superficial coating without penetration into the pores of the sandstone, which promoted a reduction in durability in both cases.