Efficacy of nanolime in restoration procedures of salt weathered limestone rock

Abstract Salt crystallisation process is one of the mostpowerful weathering agents in stone materials, especially inthe coastal areas, where sea-spray transports large amountof salts on the stone surface. The consolidation of such degradedstone material represents a critical issue in the fieldof restoration of cultural heritage. In this paper, the nanolimeconsolidation behaviour in limestone degraded by saltcrystallization has been assessed. For this purpose, a stonematerial taken from a Sicilian historical quarry and widelyused in the eastern Sicilian Baroque architecture has beenartificially degraded by the salt crystallization test. Thendegraded samples have been treated with NanoRestore®,a suspension of nanolime in isopropyl alcohol. To evaluatethe consolidating effectiveness, the peeling test andpoint load test were performed. Moreover, mercury intrusionporosimetry has been executed to evaluate the variations inducedby treatment, while colorimetric measurements havebeen aimed to assess aesthetical issues.