Un caso di degrado accelerato di Pietra leccese: la fontana dell’hotel Bellagio di Las Vegas (Nevada, USA)

One of the fountains of Bellagio Hotel in Las Vegas (USA), made of Lecce stone, was strongly affected by degradation few months after its construction. This study intend to establish the causes of the decay detected on the stone surfaces of the fountain.To this aim the following analyses were performed:observations by optical microscope on either thin or cross sections, observations of morphological features by environmental scanning electron microscope, X-Ray diffraction, Fourier transform infrared spectroscopy, pyrolysis gas chromatography/mass spectrometry analysis,determination of soluble salts content by ion chromatography, determination of carbonatic content. A great amount of salts into the stone was detected;the salts led to many cracked zones and phenomena of grain detachment; furthermore, in the superficial layer of the analyzed material an acrylic resin,probably applied to consolidate the stone, was identify.Both the salts and the acrylic resin, acting as synergistic factors, were able to enhance stone damage.