Innovative and green nanolime treatment tailored to consolidate the original mortar of the façade of a medieval building in L'aquila (Italy)

This paper presents an original, green and compatible treatment to consolidate the pointing lime plastering of the façade of a medieval Italian palace, subjected to detachments and pulverization phenomena. The cohesion between the mortar constituents was refurbished by an aqueous nanolime suspension, synthesized by a cheap, time/energy-saving and scalable method, here originally tested on historic mortars. The suspension showed a high reactivity, assuring a complete carbonation in few hours, “restoring” the binder fraction with a new-formed network of calcite nanoparticles. The treatment efficacy was evaluated by chemico-physical, mineralogical and mechanical characterization both on untreated and treated specimens.