Short- and Longer-Term Consolidation Effects of Portlandite (CaOH)2 Nanoparticles in Carbonate Stones

AbstractThe consolidation effects of portlandite (CaOH)2 nanoparticles have been determined in carbonate stones (dolostone), typically used in historical buildings from Madrid, Spain, just after 20 days consolidation at 20°C under a dry [33% relative humidity (RH)] and a humid environment (75% RH) and after 18 months under room temperature and humidity conditions (20°C±5 and 50±10% RH). The improvement of the physical and hydric properties, from short to longer term, of this dolostone is shown through the combination of nondestructive techniques (environmental scanning electron microscopy, spectrophotometry, water absorption under vacuum and capillarity, ultrasonic velocity, and optical surface roughness analyses) together with destructive techniques (mercury intrusion porosimetry and microdriling resistance measurement) also necessary for a better accuracy determination of pore structure and resistance modifications. Consolidation process under both humid and dry environment gives rise to an improvement ...