Campania's architecture has been characterised for centuries by the use of the local tuff-stone as building material because of its abundance and working facility. In the Neapolitan area the use of yellow tuff prevails 1, but the Campania's grey tuff is particularly diffused in Salerno 2. A great deal of work has been done on the features and properties of yellow tuff, but the existing literature contains only bits of information on grey tuff. As a consequence, in a research project about the renovation of Salerno's historic centre it is very important to perform a characterisation on grey tuff. In this study a chemical-physical, mechanical and microstructural characterisation of grey tuff-stone has been done. The examined samples of grey tuff come from some ancient buildings from the historic centre of Salerno and have been characterised by means of different experimental techniques 3 (chemical analysis, x-ray diffraction, thermal analysis, optical microscopy, SEM) and "in situ" analysis. Water's effects in stone walls have been studied obtaining capillarity absorption, immersion and evaporation curves; the coefficients of absorption, saturation and water vapour conductivity have been obtained. Moreover, compression tests have been carried out both on dried material and on samples immersed in water, for different times of immersion. The same tests have been conducted on quarry samples in order to estimate the amount of decay of the grey tuff previously analysed. In particular, the decay phenomena caused by humidity, air pollution, thermal gradients, salt crystallisation have been examined. The performed tests can be very useful also to evaluate the compatibility between the two materials, those used for building and those extracted from the quarries, in view of a possible substitution of the pre-existing grey tuff in the ancient buildings.
Grey tuff-stone characterization and decay analysis
INCARNATO, Loredana;
2001-01-01
Abstract
Campania's architecture has been characterised for centuries by the use of the local tuff-stone as building material because of its abundance and working facility. In the Neapolitan area the use of yellow tuff prevails 1, but the Campania's grey tuff is particularly diffused in Salerno 2. A great deal of work has been done on the features and properties of yellow tuff, but the existing literature contains only bits of information on grey tuff. As a consequence, in a research project about the renovation of Salerno's historic centre it is very important to perform a characterisation on grey tuff. In this study a chemical-physical, mechanical and microstructural characterisation of grey tuff-stone has been done. The examined samples of grey tuff come from some ancient buildings from the historic centre of Salerno and have been characterised by means of different experimental techniques 3 (chemical analysis, x-ray diffraction, thermal analysis, optical microscopy, SEM) and "in situ" analysis. Water's effects in stone walls have been studied obtaining capillarity absorption, immersion and evaporation curves; the coefficients of absorption, saturation and water vapour conductivity have been obtained. Moreover, compression tests have been carried out both on dried material and on samples immersed in water, for different times of immersion. The same tests have been conducted on quarry samples in order to estimate the amount of decay of the grey tuff previously analysed. In particular, the decay phenomena caused by humidity, air pollution, thermal gradients, salt crystallisation have been examined. The performed tests can be very useful also to evaluate the compatibility between the two materials, those used for building and those extracted from the quarries, in view of a possible substitution of the pre-existing grey tuff in the ancient buildings.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
