CHEMICAL CORROSION PHENOMENA OF ROOFING TILES

The deterioration phenomena of roof tiles in model systems, formed fro m clay minerals and Ca-carbonate component, have been investigated. Th e systems after a specific thermal treatment were exposed to real atmo spheric conditions, i.e. to attack of sulphurous acidic rains. The dua l action, of SO2 and atmospheric humidity, on roofing tiles, supportin g the destruction phenomena of samples, elucidated the formation of sp ecific phases: gel of calcium silicate hydrates and crystals of alumin ate hydrates, cancrinite, scawtite and zeolites. (C) 1997 Elsevier Sci ence Limited and Techna S.r.l.