A RAPID METHOD TO DETERMINE THE AGING TIME OF LIME PUTTY

Lime putty has been used in mortars for masonry construction for millennia reaching the maximum level of quality during the Roman empire. It is prepared by slaking quicklime under an excess of water. An increasing use of hydrated lime as a binder occurring in recent years is connected with conservation of historic buildings being the lime mortarscharacterized by appropriate compatibility with materials of ancient structures. Lime putty aged for an extended period of time manifests improved quality of calcium hydroxide, Ca(OH)2, in lime mortar or plasters. High plasticity, easy workability, reduced shrinkage and increased speed of portlandite carbonation favor, in fact, better quality of corresponding mortar or plaster. How old should lime putty be? As stablished by an ancient Roman law, an aging time longer than 36 months is necessary. This communication concerns a rapid method for verifying the effective long aging of lime putty by using the thermo-gravimetric analysis.