Industrial archaeological sites and architectonic remains: the problem of consolidation in humid areas

The article focuses on all those external areas that are to be maintained intact with respect to their amount of information, but which, due to their low resistance to atmospheric agents, require a superficial consolidation however made difficult by the presence of constant high humidity. The object of this research is a deposit of lime within the area of the "Fornace Bianchi", a site of industrial archaeology in Cogoleto (GE) (XIXth century). Three suitable inorganic consolidating products have been tested, ammonium phosphate, ammonium oxalate, nano-lime. These products, due to their inorganic nature, display high affinity and compatibility with the material object of the intervention compared to the normally used organic products. The reaction can take place even in damp conditions. Together with these products also nano-silica has been tested as comparison. The ammonium phosphate has been recently studied and in contact with CaCO3 develops its strengthening action through the formation of calcium phosphate hydrate (hydroxyapatite). The ammonium oxalate, used as "passivation" of carbonate stone surfaces for several decades, develops its action forming calcium oxalate.