Mineralogical and textural considerations in the assessment of aesthetic changes in dolostones by effect of treatments with Ca(OH)₂ nanoparticles

The present paper shows the results of the application of calcium hydroxide (Ca(OH)₂) nanoparticles on dolostone substrates. A commercial product with nanoparticles was obtained by colloidal route. The main objective is to associate the possible aesthetic changes of a dolomitic stone substrate with the mineralogical and textural characteristics caused by the applied product. The nanoparticles were applied in three different concentrations onto classical dolostone samples used as construction material. During the whole process the relative humidity was controlled. Final results correspond to an exposure period of 45 days, indicating that the aesthetic changes produced on the stone have a direct connection with the porosity and the compatibility between dolomitic stone and Ca(OH)₂ nanoparticles. The presence of carbonate efflorescences has been identified in samples subjected to treatments with higher concentrations applied on heterogeneous porous substrates.